Welding Patch Panels - Lap or Butt?

[@johnshaft5613]

The way to avoid the "gap" on the backside is to fit the patch so there is perhaps a 1/32 to 1/16 gap (if Mig welding) or just Tig weld it if you have a perfect fit.

[@yezok01]

Yes leaving a small gap and stitch welding it together is the correct way of patching a panel also applying a rust preventive and sealer on the back side of a panel is necessary.

[@Mikefngarage]

Well you gotta be pretty good to do that. i smell lots of burning through on thin sheet metal. on maybe 18 gauge that would be OK. Old cars may be Butted new ones Not so much IMO.

[@williammunny7133]

Seems to me on the lap weld, there's more area to catch salt and chemicals on the backside. Then I'm not the best judge of it because, I like butt welds over lap welds anyhow.

[@donaldappelhof2059]

It’s like what they teach in schools and what is done in the real world when you are under the clock. $$$$$

[@jonathanyates5198]

A body shop isn't going to pay you to take the time it takes to cut a patch to fit perfect. Time is money

[@mrfrank5757]

As a self taught MIG welder I had a fair number of burn throughs when butt welding 20 ga sheet metal. Lap welds were much less likely to burn through and in most areas I was going to knock down the weld and fill over it anyway. I stumbled over this point after struggling with a number of butt welds. Wish I saw your video before I started MIG welding. Many MIG welding videos suggest that lap joints are to be avoided, but I’m convinced they are wrong after seeing your video.

[@LakesideAutobody]

I like your thinking Frank. Keep in mind also, that cars are manufactured with over 4000 welds and none of them are butt welds - those seams hold up just fine. Here's another vid that clearly explains the truth: kzbin.info/www/bejne/gHqsoKGAhLulpZY Thanks for watching and the support - I'll use an endoscope to take a look inside panels to do an update video on some of the repairs I've done on this channel 2 years ago to show proof of longevity.

[@KevinKimmich44024]

Very helpful video. Thanks for the knowledge. I spent many hours trying to get cab corner to fit for butt welding on my rusted out F250, and then ended up with some fairly thin welds after grinding it smooth. I think I'll get much better results in much less time after this lesson.

[@Mikefngarage]

that is usually the case kev. only a few guys can do the magic. and on old 18 gauge butts are fine but these 22 cars nope. too thin. better off lapping.

[@SuperDalite]

Being from Frankenmuth, Michigan myself; I find your videos extremely helpful dealing with rusty panels. I’ve been wanting to take care of my father’s rocker panels on his 96 c1500 using his Miller fluxcore welder. I’ve purchased the body panels and will start tackling the work. Thank you for not only demonstrating the work but explaining the why as well.

[@LakesideAutobody]

You're welcome - glad you like them. Have a good weekend :)

[@jonathanbelanger6574]

I've done quite a few butt weld patches with flux core, yes it can be done without burning through.

[@BearBudgetgarage]

Make a video! I turn down everything to lowest setting and still get burn thru here and there on lao welds. It was 22 gauge tho. I switched up to 19 or cut pieces from old fenders to make patches.

[@SkinnySRT8]

@@BearBudgetgarage following I am about to start a cab with a Forney 140 Flux core. I have never welded. I am just a DIY type. If I have to buy a better machine I will.

[@sabergermd]

You left out a third option, "Cut and Butt", where you make the patch larger than the opening, tack it to the panel, then section by section cut away the underlying metal and tack welds, and butt weld the patch to the panel.

[@Mikefngarage]

yea that is usually how I butt weld when I do it. I do both depending on the repair. all fair game to me if it repairs the problem lasts and looks good.

[@sodiorne2]

Yep! Seems to be the best way to fix a panel. Strong as new! Can take some time.

[@DanTheManIOM]

I like to leave a gap and spot weld into that gap, or sometimes have a very small overlap and burn that edge away.

[@PompeyMatt17]

but you can't retrieve what you've cut off if you can't get to the backside

[@JohnClarke808]

​@@PompeyMatt17 then you would have to butt weld it, unless you remove the portion you cannot reach

[@gregwells2331]

I really enjoyed your explanation of butt welds vs. lap welds, this will really help me out with some rocker and cab corner work I am doing on a truck I just picked up. a fan from Canada

[@LakesideAutobody]

Glad to hear it. Lap is all that is done in regular body shops in Michigan aside from having to butt weld parts of a patch that need to be. It is my preference too but there is a quality way to butt weld panels if you really prefer that method - see: kzbin.info/www/bejne/m2rFm42Vit2ngMk

[@angelonicassio7131]

Not to mention, I love using a flange tool which I find gives much more structure in the metal around the hole plus it’s already flat when you weld. Further, I punch holes in the patch edge for plug welds. Ultra strong repair, I’ve only just started learning body work and my family and friends cannot believe the results. Of course, I’m leaning on minivans that won’t pass inspection with holes in the door. When I can afford a 1970 hemi cuda, I’ll butt weld and coach build.

[@motleyrodder5701]

One thing to note is that flanging the metal and lap welding creates an area on the body that is twice as thick as the rest. Not to mention the metal will be more sturdy due to the flange, thus more difficult to work with.

[@daveherrington9112]

Let us all know when you save up that 1/4 m for a driver quality Hemi Cuda.

[@billarroo1]

Good Pointers, before all the EPA, stuff I used to buy 1 gallon cans of ground up Asbestos with a binder mixed with water, like a putty, u plop it all around the area your welding, 1/2" away and it sucks away the heat so fast that there is hardly any warpage, Great Video

[@LakesideAutobody]

Very interesting - never heard of that

[@lcar9871]

@William_Ambrogio Yikes - asbestos! Scary how often that stuff was used years ago. You must be a "vintage" guy like me haha! There are gel sprays that are supposed to somehow wick heat away from welds - I've never tried them. I have used wet (but not dripping) strips of paper towel with decent results. Tear strips about 2" wide. Dampen then place them above and below the weld area. Blot more water onto them as needed with a very wet wadded paper towel. They will adhere to a vertical surface so no need to remove the door or fender for this. Larry

[@MrCbell57]

I see what you mean. I like the idea of a lap weld where you dont have to grind them flush. Just low enough to depress the metal for filler. And then butt weld the pieces that are more critical and show on edges and such. Very good info.

[@LakesideAutobody]

Thanks for your input Mr C. - have a good week :)

[@johnfharvey]

Great tips, have always felt guilty doing laps but now feel reassured.

[@LakesideAutobody]

Don't feel guilty at all - it's how it is done in a professional body shop. Lap welds are used where the seam can be knocked down and filled. Butts are used on edges and rigid areas that can't be tapped down.

[@ferguscolman354]

Another brilliant video ! Five years on, your experience and skills means that a novice like me ,will not grind away my welds to such an extent that they are weakend ! Well done and thank-you for all your Mig Flux Core tutorials !

[@LakesideAutobody]

You're welcome my friend - thanks for always watching through the years. 😊

[@OldJoe212]

On your lap weld's back side, you have a gap for moisture to sit. Unless you can get some seam sealer on the back, you have a greater chance of rust-out. On butt welds, you always leave a 1 mm gap. Roughly the thickness of your .024 to .030 wire.

[@LakesideAutobody]

Do you like to lap weld your patches or butt weld them? Honestly, I've never had a lap welded patch give me any problems with rusting out. The door bottoms, tail gate and quarters on that little blue truck on my channel were done in '08 - still no bubbling or rust but I do squirt some oil inside the panel after the repair - it sits in the pinch weld and really does well preventing future rust - Jerry

[@tooldemoguy]

I’m going to agree here with both of you two. In a butt weld, it’s imperative you leave a tiny gap 1/8” for the weld to seat. You will have a new weld the same thickness as the 18 g metal panel even after grinding

[@bearcat283]

Should always leave a thin gap when butt welding. Metal expands when heated and can cause the two pieces to come together at the joint. It can rise upwards because the metal has nowhere to go since there's no gap

[@nickrossi6821]

Leaving too big a gap will also cause the metal to shrink. 6 in one a dozen in the other...

[@DanTheManIOM]

Perfect timing. Just started working on a 1965 vw bus rear hatch with rust just like this. To me, lap is so much faster. I've had issues butt welding where it gets too hot and blows holes to what I am welding too. Thanks.

[@LakesideAutobody]

Good to hear. Here's some good info if you're interested - There are 3 ways professional body shops in SE Michigan fix rust: 1) Combination of Lap and Butt welds. If you insist on strictly butt welds, here's the best way to do them for longevity: kzbin.info/www/bejne/m2rFm42Vit2ngMk 2) Lap joint using structural adhesive or panel bond 3) Fiberglass cloth and fiber reinforced body filler See Eastwood’s video as to why body shops don’t butt weld then aggressively grind off the strongest part of the welds, and attempt to metal finish today’s extremely thin metal: kzbin.info/www/bejne/qKGrZmOhnZmKZpI

[@timferguson1526]

Thanks for being realistic and practical. So many candy ass welders showing off with s $5,000 tig welder doing hundreds of hours labor on a $1000 car they are going to destroy drag racing!

[@LakesideAutobody]

So glad you said that. Thanks - really. Sometimes I get discouraged looking at videos from Eastwood and other pro companies. Glad you appreciate the videos. Have a great week end. Jerry

[@joepacheco4038]

Insane half a repair

[@he-got-a-new-mommy]

Candy ass or not they have nice welders

[@andreasnystrom58]

Really enyoing your videos. Just bought a fluxcore mig welder and going to try to patch some rust holes on my project car. Never done it before

[@LakesideAutobody]

That's great to hear. Feel free to ask questions as you go along - I answer all comments 1 or 2 times a day. Let me know how it goes for you - have a good weekend :)

[@richardCorsautt]

This guy is fantastic, for real world body work! NOT over the top coach building. someone is paying to make their 10 year old vehicle look better for the next 4-5 years.

[@LakesideAutobody]

Thank you. If your looking for ideas to make a car last a lifetime you've come to the right place. I've been studying it for my whole life. I love cars :)

[@jonnyrox116]

That goes right back to what I said to you in your Citroen video, if you use .035 mig wire you need an .035 gap in your patch to ensure you get the build up on the back side. If your mig is set properly the top of the bead should be flat and the underside should be proud of the panel the thickness of the panel material, so virtually no grinding and minimal filler

[@LakesideAutobody]

I'm sure that is the correct way to butt weld two sheets of metal together but in the real world you get all kinds of irregular holes, cab corners, door bottoms, rockers etc that are so damaged it is nearly impossible to do what you are saying. Maybe a tiny little rust hole on a flat surface you could cut a perfect patch with a .035 gap all the way around but in a shop setting that's just not going to happen. I would do a video on that type of repair but I really don't want to mislead folks into thinking that is how it's done in a body shop. Have a good weekend - Jerry

[@jonnyrox116]

@@LakesideAutobody I live by the old saying, "bondo, primer and paint make a bodyman what he ain't"!

[@pauldow1648]

Appreciate your sharing your shop techniques for metal auto body. 👍😊

[@LakesideAutobody]

Glad you like them.

[@rpkietur]

i have done some lap welding patches that have held up over 40yrs. i round off corners and keep the lap to a minimum .

[@MrJwolf989]

Hello from Saginaw, Michigan! Great video, thanks for your time producing & editing.. off to work on my rusty bronco!

[@LakesideAutobody]

Hi Jack. There's a lot of folks up here from Saginaw and Flint. One of my friends I have coffee with worked for the city of Saginaw. He tells me how great it was back in the old days :)

[@mikeburton1703]

very well done... ....i realize in lap welding you must beat both the new patch {at the weld site} and the fender that you butt welded to and not go too far in beating the seam that you end up bondo ing half way up the qt. or bed side on trucks....good job guy.....even an old dog like me can learn new tricks....

[@LakesideAutobody]

You're absolutely right. Just tap in down a bit - basically putting dings all along the seam. Like a real good coworker once told me "Hit it low and fill it with dough" :)

[@annettesurfer]

Another option is punching holes around the perimeter so strips of metal could be spot welded underneath to create a "land" for the patch panel to help with the butt welding process. Punching holes in the patch could help solidify the area as well. Not the Fitzee “cut & butt" technique but it's quick and easy, plus I get a good lap type penetration without needing to hammer it down and the less filler the better IMO. To stave off potential rust inside, I typically use epoxy primer but lately I've just been coating everything with Krylon rust protector enamel since it dries in 8 minutes. Thoughts? Oh the fun I had using a Steck 20015 to can-opener out a couple complete interior rear wheel-wells from a salvage yard that didn't allow any power cutout tools, but it had to be done since only a fraction remained in the SV6. Today it's replacing rusted-out steel in a Ford Freestyle cradle/subframe/K-frame. The used replacements around here aren't great so I'll just do what I have to do.

[@LakesideAutobody]

Here's a good video on lap vs butt for patch panels - kzbin.info/www/bejne/gHqsoKGAhLulpZY and how to prevent future rust - kzbin.info/www/bejne/bonEi3WvbKx2baM

[@twgarage-terrywatson1672]

Both can give great results, when but welding take your time fitting your patch, when lap welding, you don’t need a big amount of lap over, in most cases a 1/4” is plenty. A shot of weld through primer doesn’t hurt.

[@LakesideAutobody]

You're right - most shops use both methods depending on the job :)

[@chrismitchell45]

Thank you for this video! My first attempt at patching some rust on the bulkhead of my Defender had mixed results with but welding. Mainly because of the thinness of the existing metal, luckily, none of it is on a edge. I’ll cut out the patches and lap weld it tomorrow. Thank you sir!

[@LakesideAutobody]

You're welcome -here's another vid I did on the topic because there is so much misinformation on this: kzbin.info/www/bejne/gHqsoKGAhLulpZY

[@roadiemort3589]

Tig weld to control your penetration, coach building VS bodywork.

[@richardCorsautt]

He's NOT coach building!!!

[@timcoffin2790]

100% correct. Iam not gonna jump into to the negative pool. This is production body shop work. It has its place in the world. Just as does Walmart. Timex or Rolex your choice. Time is always money. Check out another channel "Fitzee's Fabrication"

[@BradySzabo]

I guess when you have an extended cab and you get the rocker and cab corner as one piece, you should rough fit it and see if you can pund down the pillars and fillin or should you cut them at the pillars and butt weld the pillar portions? Really good video, BTW, showed me things I hadn't thought about.

[@LakesideAutobody]

Anything too stiff to knock down you can but weld solid but try not to grind the heck out of the welds and also attempt to knock it down if you can and fill. In open less rigid areas - lap weld, knock it down and fill. Here's and example of butt welding a rigid type area ( the ends of a rocker section). You can do it either way really (butt/lap) - just what works best for your situation - your choice. What ever is the easiest, will look the best, and last the longest. kzbin.info/www/bejne/aKeogYSforxobJY Here's a cab corner that's lap welded - use what you need from both videos - kzbin.info/www/bejne/f2m5h5-Pha6cnaM Jerry

[@JethrosGarage-op4bo]

Thanks for taking the time to make these videos, you are very thorough in your explanations. Keep up the good work and don't let the "nay sayers" bring you down.

[@LakesideAutobody]

You're so welcome. There are a few but can't worry about it. Happy New Year.

[@Mikefngarage]

totally agree

[@OldtimerRescue]

Hey, thank you. Since now, I had the plan to butt weld my current project. Now I will do both techniques. Best regards Ralph

[@LakesideAutobody]

Both is the key - absolutely. Generally shops that I've worked at use lap in open areas that you can easily knock the welds down and fill. Then on edges that can't be knocked down very much you butt weld. Or if the area is real rigid like a post or skinny rocker sometimes it's easier to butt. Got to be good at both ways and use to your advantage.

[@robertw5008]

Thank you sir for these videos I live in Michigan and known for rust I'm a beginner at autobody and welding just stopped at Harbor freight and picked up a titanium 125 fluxcore welder hope that will help on the welding end trying fix up the s10 truck rusted from the inside of rockers to the point it's bubbling up cab corners and the fenders are rusted as well us beginners need your videos to continue thank you sir for sharing your knowledge to help people who don't quite understand, but have a idea !

[@LakesideAutobody]

I picked up the HF $99 flux core welder to let folks know it is possible to use a non gas welder for sheet metal on cars. Give me a few weeks and I have that one uploaded :) I welded some sheet metal with it and it worked fine.

[@robertw5008]

@@LakesideAutobody will do! Thank you sir!

[@brianoneil5698]

Thanks for posting all the helpful videos. Your videos are always clear and easy to follow for even a novice like me. You just earned a new subscriber.

[@LakesideAutobody]

Thanks for subscribing - glad you enjoy the content :)

[@dukeallen432]

Another great video. Comments are good (intelligent) and your taking time to answer. Your videos will become popular. Your very good at instruction. Have promising career as instructor if you wanted. Also Great timing. Got my first bottle of shielding gas and practicing welds today. Thank you.

[@markletts2000]

How you getting on with the gas mate,.ive been using flux core ,no gas,and lm not impressed,.with the welds..I'm no professional,and gas isn't cheap,.is it worth getting?can you tell the difference.😊🇬🇧

[@husky1232]

Interesting I always thought but weld is better than lap will bare this in mind thank you Great information

[@LakesideAutobody]

I really use both methods - depending on if I can knock the welds down - if I can tap the welds down because they are on an edge, I butt weld

[@uzerap]

Thanks very much for this video, which is so helpful for an amateur like myself who will probably never become a professional welder but has an interest in doing bodywork repairs to the best of my ability. I've got a hole in my 2001 Silverado's roof and bonnet, and while I could go the plastic route I'd like to do a "proper" job. The other issue is my RHD1980 911SC which needs some attention to the suspension pan and the windscreen corners (sounds familiar to anyone with air-cooled 911 experience?!) and other bits. I will probably need to send it back to the U.K. (permanently) to get the suspension pan done as the island I live on may very well lack the crucial expertise, but I would like to have a go at some simpler jobs. Thanks once again!

[@LakesideAutobody]

In case you haven't seen this, it should give you the confidence to weld anything involved with auto body repair - kzbin.info/www/bejne/Z3O8on-DlNKMZ9U Flux core is a bit harder but still very achievable kzbin.info/www/bejne/n5SaeKqcbd5nj8U

[@uzerap]

@@LakesideAutobody Thanks a lot. Really appreciate your willingness to encourage the amateur trying to "have a go"!

[@LakesideAutobody]

@@uzerap You're welcome - thanks for watching my friend :)

[@jefferyeverly9431]

Lakeside Auto like use lap weld, but put patch behind instead on top then grind smooth>>>> lay some Evercoat-Metal to Metal/All metal filler or do some lead work just depends on the job I do old body work with lead, this is just how i do it, there's 25,000 body guys your going get 25,000 different opinions, tech ways, right way, wrong, in true metal work its the finished job that last the best....you put $4,000.00 worth paint with your $900.00 Sata HVLP spray gun, if that stuff ain't straight is going look like s@#t. 90% body=prep work, 6% paint, 4% finish. I have done 25 years auto body I started out knowing nothing still know nothing I am not "professional" nor do claim be one. I do it for fun make extra cash. I enjoy your videos keep them coming i learned little tech tips from you. As do I learn from everyone put use what best for me.

[@LakesideAutobody]

Absolutely! There's a million body men out there and a million different ways that work. Glad you enjoy the channel - Jerry

[@modgrip805]

Great video. No reason not to lap weld floors when it's going to be hidden by carpet?

[@erah3400]

some old farts want it to look 100% factory

[@michaelovers688]

HI nice video now can you please make a video on filling a panel with a lap weld and how you get filler level thanks again

[@LakesideAutobody]

Yes, sorry about the late response - Jerry

[@danielscarbrough4363]

A neat way to lap and weld a sheet metal joint is to crimp one of the joining surfaces with a crimping tool, the crimp/FLANGE tool I use is pneumatic. Your flange tool my be a little different than mine, test a scrap to be sure...then (if appropriate) we will to cut our patch roughly 1/2" larger than the area to be replaced, then crimp the joining original surface where your patch will meet, letting it in the same thickness of the sheet metal with approximate 3/8" flange. Then check and final trim to fit, align, clamp and tack weld..make any last adjustments then stitch it up and grind flush. There will be approx. 3/8" overlapping surfaces after crimping (considering the thickness of the metal) so there is a little room for adjustment. Depends on the job, sometimes I like to drill several holes through the overlap and screw it in place before even tacking it...especially when making one good front fender out of two half rotten old classic gems, joining a good front half with a good rear half of a rare impossible to find front fender. When it can be accessed as with a fender and most areas, one can clean up the weld burns and undercoat the seam on the other side.

[@LakesideAutobody]

Thanks a lot for the information and tips. There's a lot of good ways to fix rust damage :)

[@AndrewB23]

From my understanding lap welding is lazy and improper because it creates a pocket that can collect moisture and just rust away putting you back where you started

[@LakesideAutobody]

That's bad information from the internet - here's the truth on the subject - kzbin.info/www/bejne/gHqsoKGAhLulpZY Cars are build with thousands of welds and not one of them is a butt - for good reasons :)

[@jeffhuffman5433]

I have learned a lot watching your videos. Thanks.

[@LakesideAutobody]

You're welcome Jeff - I appreciate the support - enjoy the weekend 🏈🛠😊

[@firelaperriere6026]

As many have stated, the butt weld had way too little gap. That is why the penetration isn't good, also don't be so light on the trigger no need for skimpy tack welds and low heat if you take time and use air to cool the welds in between. I understand that you are trying to show the difference between the two but it should be properly done for a comparison. I disagree with the replies on it being a time based decision and i disagree with your idea that a flange weld is "stronger" so it is better in the sense that it needs to be twice as strong with two layers when sheet metal is only one layer thick from the factory. Putting panels that close together doesn't account for expansion furthering the possibility of warping. Not knocking you or the way you do things in your shop just commenting on the way you presented the difference. A DIY guy should be taking their time on the cars and projects they love to do it the best way possible. Lapping is fine for high volume shops, but I don't think it is the correct way for someone to learn to do it for personal cars when considering to them what they are doing is a quality restoration.

[@LakesideAutobody]

Pls direct the viewers to a video that shows how to repair the rust in this video using only butt welds :) kzbin.info/www/bejne/aWfdnJZviraUitU

[@philliparthur8672]

I'm not a welder and thought butt welding would be best and thank you for showing me lap is best. I'm thinking about getting a welder and trying it out on my truck. Would one of those 100 to 120 dollar welders be worth it? I'd appreciate your feedback.

[@LakesideAutobody]

MIG (gas welder) is easier but check this video out for the 100 dollar welder - kzbin.info/www/bejne/n5SaeKqcbd5nj8U Works just fine with a little practice :)

[@philliparthur8672]

@@LakesideAutobody Thank you I'll check it out. I hate paying someone else if I can do it myself and I think with a little practice I can. Again thank you for replying.

[@classicrestouk]

The trick to a good butt weld is the root gap. If the panels are tight fitting, the weld pool won't be the same on both sides. With the correct spacing, the root will allow the pool to flow through and give the correct penetration and you will get a panel welded perfectly.

[@LakesideAutobody]

That is true but in a real world setting that gap is not always going to be perfect - especially with severe Michigan rust. Check this video out for more on lap vs butt: kzbin.info/www/bejne/gHqsoKGAhLulpZY

[@fordchevinman4614]

Great video, informative for a beginner such myself.

[@LakesideAutobody]

Glad you liked it my friend - have a good week :)

[@gringotom242]

Thanks this is one of the most useful videos i have seen

[@LakesideAutobody]

Glad it was helpful. Have a great week :)

[@eapauto]

Good detail on patch panel welding.

[@waynecummings5021]

Very informative, thanks! I'm about to attempt to the onside rear wheel arch on my Honda Civil and I am nervous. I love KZbin!

[@LakesideAutobody]

Feel free to ask questions as you go - I get to them 1-2 times/day

[@waynecummings5021]

@@LakesideAutobody I do have one at the moment:- What if I can't get to the reverse side of the TIG or MIG weld to clean it up? If it's not exposed to weather/water, will it corrode? I guess it will as most metal oxidizes, but can it be protected in any way?

[@LakesideAutobody]

@@waynecummings5021 If you can't get to the back side to undercoat, squirt some used motor oil inside the panel and let it creep around and coat everything like an old valve cover. (after you paint) This video explains - kzbin.info/www/bejne/bonEi3WvbKx2baM

[@kj9219]

Excellent vid. Good to know my lap weld to fix the lower fenders on my F1 was an OK thing to do. I've wondered if I had done it wrong because it wasn't butt welded. Yae!

[@LakesideAutobody]

You can do it either way it doesn't matter really. If the panel is going to rust again it's not going to start up high - It will begin again at the bottom of the panel where salt water and debris sit.

[@fakename2481]

Awesome, simply awesome information.

[@timferguson1526]

interesting note.. when I didn't have a welder if cut rust out of a trunk in a camaro. I ground it clean and used steel pop rivets to hold in on, fiberglass and Eastwood encapsulated it. That was 1987 and the car had been outside ever since. NO signs of rust and it looks the same as when I did it. There is no butt weld that isn't porous to some degree. It doesn't matter how you weld it you better fill it with cosmoline or coat the inside with automatic transmission fluid or something. Butt welds are razor thin and just make you feel better. a good lap weld us strong and will outlast a crappy butt weld. There is more than one way to skin a cat. If you can fix something and it lasts 25 years, nobody can tell you it's wrong.

[@LakesideAutobody]

Nice. Absolutely agree with your views on fixing stuff! I would like to experiment with something like JB welding a patch on - just for folks that don't have access to welding equipment. I actually think it would last very long. I like the way you think! Jerry

[@scottevans7031]

@@LakesideAutobody look up a product called 3m 8115 panel bonder. way better than jb weld and will do exactly what you are talking about.

[@firelaperriere6026]

Incorrect. have you seen the backside of a properly penetrated weld on sheet metal? Has an extra 50%+ of metal and structure behind it as well as a good flush grind on the front will minimize thinning. I don't know where you get razor thin from. BTW that porosity you are talking about on a butt weld can be nonexistent or minimal compared to that huge gap you have in between the layers of a lap weld. Not saying you did it wrong or knocking you but i think your spreading some misinformation there. One last comment, saying some thing along the lines of butt welds only make you feel good is an excuse to make you feel better about doing it your way. Many ways to do it and nothing wrong with either way just a lot of misinformation in the comment section.

[@donaldappelhof2059]

Thank you for taking the time for us yeahoo’s!

[@LakesideAutobody]

You're welcome Donald - thanks for the support and watching :)

[@franksgarage8551]

Im in the midst of this right now. Im leaving a gap to butt weld. Lap welds trap moisure too. Unless you can seal it. Another one is stepping the parent metal then lap weld the panel in. They all need sealing from behind for a permanent repair. Rust starts the moment a weld cools.

[@LakesideAutobody]

Remember though that lap welding is like a shingle on the inside.... the seam is upside down moisture has a tough time traveling up. The bottom of the patch is usually the bottom of the car which is a pinch weld or just open. Hope that makes sense :)

[@432b86ed]

No more stalling. I got this. TY

[@adollarshort1573]

Thanks,AGAIN, Jerry! In regards to the 1st part with a SMALL totally lap- welded patch on any panel with space behind it,could the patch be applied from the back of the existing panel and welded? Then knock down the welds and fill the patch area and blend into the rest? It might be easier and look better in some cases. I know very little about this trade so forgive me if this is a stupid question! Also, I would have never thought about a "combination" lap/ butt patch! Thanks again!

[@LakesideAutobody]

Yes. You can fit it behind if you can. It's often hard to do because the patch is always bigger than the hole. Here's another video on this topic - I think it explains better - kzbin.info/www/bejne/gHqsoKGAhLulpZY Lap is how the factories did it for years when they attached the quarter to the roof at the sail panel - a lap weld in a valley filler with lead or plastic filler :)

[@mikegordon3436]

Why lap weld instead of just glues it on ?

[@canadianmarauder1923]

Interesting video. I been butt welding only so far. Doing a restoration and it just seems right thing to do. I’m also welding back side cause of what you said about welds getting too thin. Always learn something from you. Thanks

[@LakesideAutobody]

You're welcome. Use small overlap - weld solid - no moisture - especially if you keep the drain holes clean (most important thing in rust prevention). Please see this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs Good luck - the method you use is really up to you and what you think lasts the longest :)

[@rgc1961]

Check out Fitzee's Fabrications 'cut and butt' technique. He's from Newfoundland, and he's amazing!

[@tooldemoguy]

Another great video! Nice release, brother

[@ojscustoms9251]

My personal opinion on this is that it really depends on the project. If you're doing a higher end job I would never lap weld in the middle of a door or any panel for that matter. Really any panel that will see direct sunlight and be right in the viewers eye. There is a very good chace it will ghost back and you will see it. Small rust repair on a daily driver, sure why not. Its must faster and frankly on jobs like that, time is money!

[@LakesideAutobody]

You will never notice any of these repairs. The same methods found on this channel are used by one of the best body shops in the thumb area of Michigan - I know cause I worked there. Follow the steps exactly as you see on the videos and you'll be fine. Here's a video of a Charger I painted while working at that shop - It still looked perfect 20 years after painting it: kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@williamgrissom9022]

You didn't mention protecting the metal. When lap welding, you should spray the overlapped areas with high-zinc "weld-thru primer". An easy version is Rustoleum galvanized-metal primer spray cans, at most hardware stores. Any bare metal on the backside will quickly begin rusting, especially any tight gaps which can hold moisture.

[@LakesideAutobody]

Some manufacturers are actually getting away from that as it affects the weld pool. They recommend treating the seam after the welding process. see this video for info on a simple way to for treating after: kzbin.info/www/bejne/bonEi3WvbKx2baM

[@williamgrissom9022]

@@LakesideAutobody Oil works, and one reason I don't fret about minor oil leaks in my cars which blow oil underneath while driving to coat the bottom-side of the vehicle. I vaguely recall reading that one treatment is to form a porous black-oxide on a surface which is then soaked in oil. The oil remains to repel moisture, though the surface appears dry. That might be the trick in tools like black impact sockets and protecting firearms. For items like nuts and bolts that I don't have time to paint, plus the paint will scrape off when installing, I spray Rustoleum Rust Preventer, which seems like a waxy oil. It states "6 months outdoors" but I expect it lasts much longer when out of he elements. To remove surface rust on parts, I soak for a few days in phosphoric acid, which you can buy as concrete prep at Home Depot. I think it converts rust to black iron-phosphate, which either flakes off or can be wire-brushed, and left in deeper pits to hold oil to protect.

[@LakesideAutobody]

@@williamgrissom9022 Good information - thanks William - Jerry

[@cdnbroncolife1889]

To those who have watched this video Please don’t let this video scare you. Butt weld is the way to go .. 100% Look closely at the butt weld 1. Not enough proper gap left before he started welding 2. Not even welding along the seam or butt of the metals resulting in what you see 3. Not enough overlap in the spot welds I’m no pro but it certainly didn’t take me more than by the end of the first day of using my mig for restoration purposes to butt weld a sheet panel and have the backside look like little overlapping “buttons” in line with the seam. Good luck , take this video with some discretion

[@LakesideAutobody]

With all respect and truly wanting to help, strictly butt welding is not the way to go for these reasons - Strictly butt welding a patch panel, which has become popularized by the internet and TV, is not the best quality repair on today's thinner metal and there are many good reasons why professional body shops don't do it. Shops use a combination of both lap and butt (butt for rigid areas that can’t be tapped down) on almost every patch but would never just butt two pieces of metal up (gap or no gap), weld it, then grind away at the area attempting to metal finish it. Here why with good reason - especially Eastwood’s starting 22 seconds in: kzbin.info/www/bejne/qKGrZmOhnZmKZpI * kzbin.info/www/bejne/g5eunYGHe5Kiaqs * kzbin.info/www/bejne/m2rFm42Vit2ngMk Today’s metal is .030. That is literally 6 hairs (hair is .005) thick. You start grinding on that and the result is paper welds & surrounding metal. In the end it’s what works for you though. Keep in mind, you won’t find anyone butt welding in professional shops. Surely you’re not going to butt weld and metal finish this: kzbin.info/www/bejne/aWfdnJZviraUitU or some of my other rust repair videos. Use small overlap, weld solid and you won’t have to worry about moisture - especially if you keep the drain holes clean (most important thing in rust prevention). Note that the opening of the seam is upside down on the inside (no moisture trapped). Please see this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@cdnbroncolife1889]

@@LakesideAutobody appreciate the reply. We will agree to disagree. Agree to use different techniques at different times (fit for purpose ) Thanks But your example of butt welding was horrendous and only served as a scare tactic to those not knowing that it can be done much better than that. Cheers

[@andywells397]

Just cut a patch slightly lager than the hole, then mark it, cut around the marks and the patch will fit perfectly. Dont keep trimming the patch to fit the hole it will take forever...well thats how us brits do it anyway

[@drycreek3204]

If you lap weld, there is a nice opening between the two panels for salt & water to get into. That will rust away real good!

[@LakesideAutobody]

kzbin.info/www/bejne/nXq2YoeYq5x-rNk Check this out to make a really informed decision on the subject - can't listen to the TV, magazines and advertising - most have not studied it for years. kzbin.info/www/bejne/gHqsoKGAhLulpZY

[@zeke112964]

Just curious ...why didn't you show the back side of a lap weld compared to the back side of the butt weld you showed?

[@LakesideAutobody]

Good question. The lap weld would be very similar in that there will be small gaps or imperfections but the lap weld has the advantage of being faster, easier, saves on grinding discs, and holds up very good because you have a thicker layer of body filler over the repair. If you seal or coat the back side with some good undercoating it will last longer than us. I do not over lap the patch enough to trap moisture between the layers plus I like to spray the back side with used motor oil to stop rust. Hope this answered the ? if not ask again. Jerry

[@apples13able77]

@@LakesideAutobody I've been using the Penetrol, haven't tried spraying it yet tho, but I use it to protect my bodywork before I get to the bondo stage, trying to work out drive ability issues w my F150. I can brush the Penetrol on, it will seep into the crevices to protect them after I sand to Bondo Glass it. Then I'm thinking of using it as a "primer" and then spray that professional enamel Rustoleum spray can- thinking this may not be too bad a repair since my pneumatic spray paint situation isn't there yet - need to make a water separator and gun etc. But also looking for the effective inexpensive "quick-ish" decent repair to get my beater on the road again... not sure how good Penetrol is as a primer, I know it will wear off if not painted over. I may do some tests of my own, if I do a vid I'll send it to you, The tests may be a bit inconclusive since Father Time is the real test but exposure to the elements... ie try it on a "metal roof" test panel- anyway, another great vid! Thanx!

[@LakesideAutobody]

@@apples13able77 Excellent - look forward to hearing from you and how the experiments work. I've heard good things about Penetrol - have a good week

[@altheboss5722]

@@LakesideAutobody great video but i must say saving grinding disks cannot be an objective.you hv mentioned it several times in the video how much do these things cost were you live? I want the best outcome if i hv to go through 5 disks per door.

[@LakesideAutobody]

@@altheboss5722 In a body shop environment the boss/manager won't stand for it - anyone doing that would be laughed out of the shop. There's no need for it. Please see these videos for longevity of lap welding and the methods seen on this channel: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@abdulhamoui4376]

Like you clips dude , could you put the patch behind the panel then weld? Less grinding and not high and fill in with body filler?

[@LakesideAutobody]

I'm not going to say it can't be done. What I will say is you'll have to try it to find out for yourself if is something that will work for you.

[@motoman730]

Nice video...I overlap most of my repair panels...it's faster to do..!!

[@LakesideAutobody]

Glad you liked it - it is fast and it does hold up very well especially if you coat the back with some good rubbery undercoating of some good old used motor oil - after you paint. - Jerry

[@scottiejones3518]

What technique is best to fill small circle shaped holes that you want closed? From screws or bolts that are no longer being used. Can you do a plug style weld with a piece of metal as a backer?

[@LakesideAutobody]

Absolutely - I've done that plenty of times. Just weld it up like you said, grind the welds (just a bit), knock the area down and fill. Jerry

[@scottiejones3518]

Lakeside Autobody Thank you, and I love your videos!!

[@600miles]

How about flanging a patch panel and spot welding in place?

[@LakesideAutobody]

You could do that for sure. What about the corners? Maybe a round patch?

[@Greenturkeyman]

Still a great video

[@almierz4604]

HOW ABOUT PUTTING THE PATCH ON THE INSIDE ( LAP) AND WELDING AROUND THE PERIMETER , ( OUTSIDE ) WHILE HOLDING THE PATCH WITH A MAGNET , THEN JUST FILLING THE LOW AREA WITH BODY FILLER . THANK YOU AL.

[@LakesideAutobody]

You could do that but then know that the overlap will hold water on the inside as it will be facing up now. It is a bit harder to hold the patch in place too as you can't press it against the other panel. Your choice though - if it works for you - perfect. Jerry

[@0tt0mobile]

You still have an area of raw metal edges on the backside for the saltwater to start corroding, on the lap joint.

[@LakesideAutobody]

Remember, only the internet dislikes lap welding - new cars are lap welded together and all body shops use lap. I always use a combo of both though depending on the situation. I also have a video on butt welding patch panels. Use small overlap - weld solid - no moisture - especially if you keep the drain holes clean (most important thing in rust prevention). Please see this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@Dave5843-d9m]

Regardless of weld method, the back side has to be fully protected with cavity wax or some other rust stopper. Ignoring the hidden inside, will have it rusted through in under 2 years.

[@LakesideAutobody]

That is a good idea but if you just squirt some oil inside the enclosed panels they'll last way longer than you'll have the vehicle - kzbin.info/www/bejne/nXq2YoeYq5x-rNk Still perfect today actually - about 5 years :)

[@artyberkhoff8878]

Looks like you have been doing this for a long time and any professional knows there is no profit in comebacks. I appreciate you taking the time to show what your experience has taught you. Do you treat these new tin foil cars the same Id like to see these armchair body men butt weld a honda!

[@LakesideAutobody]

Thank you so much. Sometimes the critics are a bummer because you want the viewers to learn the easiest, practical and normal methods. There are a lot of fancy products out there trying to get your money but really the most practical ways from back in the old days are still relevant, and used in shops today even on a Honda. Happy Holidays

[@diyoregonnowtexas9202]

Hobbiest here. If i do a lap weld on the side a a pannel, that piece is higher than the pannel. Wont it look like a high spot after paint?

[@LakesideAutobody]

You knock the welds and high spots down before proceeding with the repair. With respect, lap welding is how all body shops in Michigan repair rust (welding or adhesive). Strictly butt welding a patch panel, which has become popularized by the internet and TV, is not the best quality repair and there are many good reasons why professional body shops don't do it. Shops use a combination of both lap and butt (butt for spots that can’t be knocked down like edges) on almost every patch but would never just butt two pieces of metal up, weld it, then grind away at the area attempting to metal finish it. Here why with good reason - especially Eastwood’s starting 22 seconds in: kzbin.info/www/bejne/qKGrZmOhnZmKZpI * kzbin.info/www/bejne/g5eunYGHe5Kiaqs * kzbin.info/www/bejne/m2rFm42Vit2ngMk Today’s metal is .030. That is literally 6 hairs (hair is .005) thick. You start grinding on that and the result is paper thin metal and welds. Lap and Butt methods can work well if done properly so in the end it’s what works for you.. Keep in mind, you won’t find anyone butt welding in professional shops. Surely you’re not going to butt weld and metal finish this: kzbin.info/www/bejne/aWfdnJZviraUitU or some of my other rust repair videos. Use small overlap, weld solid and you won’t have to worry about moisture - especially if you keep the drain holes clean (most important thing in rust prevention). Note that the opening of the seam is upside down on the inside (no moisture trapped). Please see this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@alexbaxter9512]

You mention that there is a problem with corrosion starting at the rear of butt welds, surely it'll be worse with lap welds, there'll be a perfect crevice for corrosion to start in behind the patch?

[@LakesideAutobody]

Here's a couple vids that will help on that exact topic. kzbin.info/www/bejne/gHqsoKGAhLulpZY & kzbin.info/www/bejne/bonEi3WvbKx2baM

[@alexbaxter9512]

@@LakesideAutobody So it's all just a matter of opinion...

[@LakesideAutobody]

@@alexbaxter9512 I just read a paragraph from a 1950's Ford Shop Manual that states the correct way to do repairs like this. I can send you that if you would like - Their instructions are: Weld it into place (shows lap) ---- Tap seam below surface with grooved dolly (never saw one myself) --- "tin" the welds and fill the groove in with lead ---- metal finish. Interesting..... I was always looking for something like that and a fellow in the comments sent it to me. I'll make a video on it far all to see - I think it would really help folks make up their mind

[@alexbaxter9512]

@@LakesideAutobody Yes, they would use oxy acetylene welding in the 50's, (the good old bad old days,) you'd be really skilled not to have distortion with gas welding so beating it in and leading it would probably be the only option.

[@LakesideAutobody]

@@alexbaxter9512 My dad used to braze and like you said, it had to be real tough dealing with distortion issues. I tried it a few times but got a job elsewhere where they used MIGs and that was the end of that :)

[@jmyers9853]

there is no way around it, the "fit" is extremely important

[@LakesideAutobody]

I'm not sure if a guy could get a good fit on this type of repair - kzbin.info/www/bejne/aWfdnJZviraUitU - Let me know honestly if a guy that butt welds exclusively would even try this

[@khamkham7134]

nice video... do you have an example of your knockdown technique? how are you controlling the blows?

[@LakesideAutobody]

Check this out at 14:20 - kzbin.info/www/bejne/a2TQmnSFl7SXjLs

[@Mikefngarage]

This is EXactly how I learned and do it. Haters need a few more years experience.

[@LakesideAutobody]

Thanks for the support. Lap is how all body shops in Michigan fix rust or should I say fixed rust. A lot of shops stay away from rust repair.

[@Mikefngarage]

@@LakesideAutobody When I was a painter in a body shop many years ago. If someone repaired a quarter, like replaced a section and Butt welded it in they would loose their contract if the adjuster saw it. All these young guys are saying butt is the RIGHT way to do it. I say on an old 16 gauge car or a 18 gauge car it is fine but on a newer 22 no way. not safe.

[@Mikefngarage]

also in a blind area you could possibly clamp on a patch panel with panel adhesive then there would be no possibility of the water getting through the 2 layers. Not that it will happen that easily

[@LakesideAutobody]

@@Mikefngarage You are so right! I don't want to hurt anyone's feelings or be negative but the truth is, a guy would be laughed right out of the shop if he attempted to butt weld the whole patch panel - really. He would not last long - very slow, inefficient and just not the right way to go about it - poor quality too - see Eastwood’s vid starting 22 seconds in: kzbin.info/www/bejne/qKGrZmOhnZmKZpI. That's just the truth, it's not to be degrading to anyone or disrespectful, it's just the way it is and was. You are right on with the thicker old cars like the 20's - 40's too - That you can probably butt weld and metal finish - not today's metal. Have a great weekend :)

[@LakesideAutobody]

@@Mikefngarage Absolutely - like this maybe: kzbin.info/www/bejne/rYPPYoScoNd1m7s

[@mustanggarland24]

Holy crap I am so glad I seen your videos! I totally subscribed to your channel

[@LakesideAutobody]

Thanks for subbing. I'm glad you enjoy the videos - I'll keep them coming :)

[@scottiejones3518]

So what do you do when you have ground down the welds and there are little tiny pits in it? They are not holes just tiny pits. Do you fill them? Will there be issues with paint bubbles later on? Thanks for any help!

[@LakesideAutobody]

Good question. First, remember that if the panel is going to rust again it will begin at the bottom where the salt water and debris gets trapped. Up high it stays dry or drys out. 2nd, Of course you are going to get a few bad welds - you're not a machine - it happens to everyone - even ones that say it doesn't. If it does, you can grind it down a bit and hit them again with the welder or like me, I do my best, grind them down, sand blast them clean, knock them down and fill. If you expect perfection, you'll get frustrated. Hope that helps somehow - Jerry

[@scottiejones3518]

Lakeside Autobody Awesome, thank you for your help! Your videos and help have made a world of difference! Much appreciated!

[@LakesideAutobody]

@@scottiejones3518 You're welcome - have a great week :)

[@appliancedude63]

Very practical for diy. Thanks for sharing.

[@LakesideAutobody]

You're welcome - Jerry

[@pickleball_tomorrow]

Thank you for the knowledge sir

[@LakesideAutobody]

You're welcome SVT - thanks for watching :)

[@stevefuller1779]

i almost always lap weld, butt joins look nice but everything has to be perfect which is hard to do with insitu repairs, also time is a factor when a customer is paying you to repair, you have to strike a balance between cost and perfection, obviously if it's a showcar you will want totally invisible repairs but many people are just wantig to extend the life of their car not win concours.

[@LakesideAutobody]

I agree. See this video it may give you more confidence in the longevity and looks of laps - kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@joelkoonce8559]

You da Man !!!

[@kellyappel3015]

I know this is old, but it's one of few discussions on this topic. I'm doing wheel arch patches on a pickup and going back and forth on lap welding, butt welding, or maybe even gluing the panels in place. What concerns me most is that with lap seams (welded or glued), ghosting shows up later on. Apparently, on a warmer day, as the steel warms up, the joints that are doubled up take longer to expand than the single layer of steel and a line is visible. It's only noticeable by eye. You can't feel it, and I'd have to believe you wouldn't be able buff it away either, as it's not a flaw in the filler or paint. Anyone have knowledge of this or experienced it???

[@LakesideAutobody]

You'll never have it if you knock or tap the seams down. If you grind the heck out of the welds, try to metal finish the patch, and have the seam right under the paint it'll likely occur. Weld how ever you prefer lap or butt, knock it down and fill - no problems. Check this follow up video out - still looks the same even today 3/2023 - (5 years) kzbin.info/www/bejne/nXq2YoeYq5x-rNk

[@kellyappel3015]

@@LakesideAutobody Thanks for the reply Jerry. Just to be clear, what I'm talking about is a perfect looking repair that shows no line when cool...and as the vehicle warms up in the sun, a ghost line appears where the seam is. It's not a flaw in the bodywork, but a difference of expansion as the panel warms up.

[@LakesideAutobody]

@@kellyappel3015 You should never have a problem with that - really. Remember every sail panel from the 60's 70' and 80's was done in the very same way from the factory. A lap joint in a shallow channel, then leaded or filled with something other than lead (later models). The sail panel is where the roof connected to the quarter panel behind the quarter glass or back of the side doors :) One of the best body shops in Michigan and many others in Michigan use this method. I really believe the key is tapping the seam down so there's a buffer between the seam and the finish. When any seam, no matter how it was done, is directly under the finish, you're asking for trouble 😊

[@kellyappel3015]

@@LakesideAutobody I understand what you're saying, but (if you were to search), there has been issue with ghosting on lap jobs. Not with all, but enough to say there's a problem. As long as we're chatting, what's your opinion on a recessed glued seam? Does 3/8" give enough of a seam for 3m's (or similar) panel bond to hold?

[@LakesideAutobody]

@@kellyappel3015 With a ton of respect, I'm sort of curious if you have ever seen ghosting with your own eyes or is this something you've read about in magazines or heard on TV. A ton of guys talk about it online but they most likely talking about jobs that were done incorrectly. As for 3/8" for a flange.... I would not feel good about it my self (just me though) - that's why I don't use a flange tool for glue. You can certainly use the flange tool if you weld though. Let me know what you're thinking 👍

[@Imwright720]

If you overlap it wouldn’t you have a problem if rust gets between the 2 panels. Since you can’t get to the inside salt water will get into the overlap and soon rust it out. You have actually increase the area that could be affect 4x’s. The butt weld is actually a much smaller area to be affected. I guess I’m confused.

[@LakesideAutobody]

No it would not - I've never had rust get between the panels (it's < 1/4" overlap) that's internet fake fear. Been patching rust like that since 1984 never had a patch bubble. Cars rust from the bottom of the panel up because moisture sits down there not on the side of the panel. Squirt oil in the panel after the repair to protect that lower area. Really... see this video for the truth. kzbin.info/www/bejne/bonEi3WvbKx2baM

[@lostjalopygarage8150]

Do you recommend weld-through primer? Thanks for the video. It helped me decide to do lap welds for my floor pans and rocker panels. It's an old car (50 Plymouth business coupe) in rough shape all around and at best I plan it for a daily driver. Most stuff will be hidden so I'm not worried.

[@LakesideAutobody]

I don't use it. Here's a bit from an article on the subject: "Once other OEMs started backing off on the use of weld-through primer - Tobie cited FCA, for example - Honda began to study the effects of such typically “zinc-rich primers” on welds, particularly on higher-strength steels, he said. The OEM found that the zinc can contaminate the weld pool, particularly when too much weld-through primer is used - “which it often is,” Tobie said. (And if the surface isn’t prepared correctly, the primer does you no good by flaking off anyway, he said. A better option would be to make a weld, and then use a corrosion-inhibiting primer after the weld is done." Tobie said. www.repairerdrivennews.com/2016/12/08/honda-explains-rationale-for-new-change-in-weld-through-primer-rules/#:~:text=%E2%80%9CWeld%2Dthrough%20primer%20should%20not,affect%20weld%20or%20joint%20quality.%E2%80%9D Here's a video on how I treat it after the repair: kzbin.info/www/bejne/bonEi3WvbKx2baM

[@mohawksniper79]

If you bevel your edges for what he called a butt weld and set your welder right you should have little to no grinding and full penetration. It takes practice but is worth it.

[@LakesideAutobody]

I agree with beveling the edges - that is the way you should butt weld a patch - I prefer lap welding though just because you can repair massive rust holes and damage - there's not a rust hole out there that can't be repair quickly and efficiently using lap Please see this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@paulcarter2907]

Surely on the back of the lap weld patch, you will have a complete circle of a gap, that you didnt like on the butt weld..! Or am I missing something?..Cut the patch first, lay it over the bad metal, scribe, cut leaving the width of wire, magnet, then MIG Stick or TIG..But I.m not an expert....

[@LakesideAutobody]

That's what the magazines, TV, blogs want you to believe. That you're welds will be perfect. Remember, in the real world, you're welding upside down, sideways, galvanized metal, thin metal, extreme rust repairs, etc. If you butt welded a patch on a gas tank and ground the welds flush would you trust it? Would you light a match near the welded patch? One pin hole and your paint bubbles. On a lap welded patch only the top of the patch is usually a lap - and the seam is upside down like a shingle on a roof. It won't hold moisture. The bottom of the patch is usually the bottom of the vehicle panel and either open or plug welded to an inner panel. In a real body shop setting you use both really - lap where the seam can be tapped down and butt where it can't. In every day driving the lap welded seam usually outlasts the butt welded seam. That's just my experience over the past 40 years of rust repair in real body shop settings - and you don't want come backs because then you're working for free. Hope this helps a bit. See this vid for more real world info on the topic - kzbin.info/www/bejne/gHqsoKGAhLulpZY

[@danielb2145]

Interesting, I'm always scared that rust will start again behind overlaps where you can't paint.

[@LakesideAutobody]

These videos may help answer some ?s: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@Mikefngarage]

lasts many years depending on where the car is and how its treated. coat the backside with seam sealer on a car you can and if its newere its gonna rust out somewhere else if in the rust belt.

[@appleapple3855]

In my head I kept saying, "you're a butt weld!"

[@LakesideAutobody]

Nice.

[@dazad1972]

should always leave a tiny gap between the joint so the weld fills it. try using butt weld clamps they are great to work with. plus if you need to, its easier to use hammer and dolly on butt welded panels. not so easy on a overlaped joint, but hey what ever works for you. im only a hobbyist not a pro.

[@LakesideAutobody]

Thanks for the tips:)

[@MrCook-kl2qe]

On the but weld, the welds were off center which caused the gap.

[@LakesideAutobody]

Check these videos out for a clear picture of what I'm trying to get across it this vid. kzbin.info/www/bejne/m2rFm42Vit2ngMk kzbin.info/www/bejne/qKGrZmOhnZmKZpI*** kzbin.info/door/CRd-C63GOe5ZhHPKO6gHmw

[@johnrobison4635]

The main problem with lap welds is there is no way to eliminate ripples or dimples at the site of the patch. On average street cars it would probably be fine but on classic or show quality cars lap welds would never do unless you create a lip to lay the patch in flush with the body panel.

[@LakesideAutobody]

You only have to read this if you are interested in the truth. With respect, lap welding is how all body shops in Michigan repair rust on late model vehicles (welding or adhesive) the seem is tapped down and filled. Strictly butt welding a patch panel, which has become popularized by the internet and TV, is not the best quality repair on today's thinner metal and there are many good reasons why professional body shops don't do it. Shops use a combination of both lap and butt (butt for rigid areas that can’t be tapped down) on almost every patch but would never just butt two pieces of metal up (gap or no gap), weld it, then grind away at the area attempting to metal finish it. Here why with good reason - especially Eastwood’s starting 22 seconds in: kzbin.info/www/bejne/qKGrZmOhnZmKZpI * kzbin.info/www/bejne/g5eunYGHe5Kiaqs * kzbin.info/www/bejne/m2rFm42Vit2ngMk Today’s metal is .030. That is literally 6 hairs (hair is .005) thick. You start grinding on that and the result is paper welds & surrounding metal. In the end it’s what works for you though. Keep in mind, you won’t find anyone butt welding in professional shops. Surely you’re not going to butt weld and metal finish this: kzbin.info/www/bejne/aWfdnJZviraUitU or some of my other rust repair videos. Use small overlap, weld solid and you won’t have to worry about moisture - especially if you keep the drain holes clean (most important thing in rust prevention). Note that the opening of the seam is upside down on the inside (no moisture trapped). Please see this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@teamdrummond6915]

Thank you, sir. Good video.

[@LakesideAutobody]

You're welcome TD :)

[@jameshendrix8217]

People have to understand that he's in a BODY SHOP environment where people ain't going to pay for tig welded butt welds and no filler repairs. He's not RESTORING porches and lambo's. Anyone whos done bodywork knows how time consuming it can be. They got to get the cars in and out to make $$$$. Now would I do this on my project car at home ...probably not, but I have the time, what I don't have is a customer on my ass asking when can I pickup my car. Good repair for your daily beater, not for your classic or high $$$ car. Lakeside Autobody no negativity implied cheers

[@LakesideAutobody]

Thanks for the comment and the support but here's where I stand on that stuff. I use a combination of both lap and butt on almost every patch but I would never just butt two pieces of metal up, weld it, then grind away at the area attempting to metal finish it and neither would any body shops in MI, for many reasons but here are 3 really good reasons: kzbin.info/www/bejne/g5eunYGHe5Kiaqs kzbin.info/www/bejne/qKGrZmOhnZmKZpI kzbin.info/www/bejne/m2rFm42Vit2ngMk Today’s metal is .030. That is literally 6 hairs (hair is .005) thick. You start grinding on that and the result is paper thin metal and welds. Lap and Butt methods work well if done properly so in the end it’s what works for you.. Keep in mind, you won’t find anyone butt welding in professional shops. Surely you’re not going to butt weld and metal finish this: kzbin.info/www/bejne/aWfdnJZviraUitU or some of my other rust repair videos. Use small overlap - weld solid - no moisture - especially if you keep the drain holes clean (most important thing in rust prevention). Note that the opening of the seam is upside down on the inside too. Please see this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@brianshambleau3913]

what's the back side of a lap weld look like? a little pocket?

[@LakesideAutobody]

If you have a very small overlap it is an upside down super small pocket so no moisture can get trapped. Usually the patch goes all the way to the bottom of the panel so you almost never have llap joint facing up. See this video for longevity of this type of repair if done correctly: kzbin.info/www/bejne/bonEi3WvbKx2baM or kzbin.info/www/bejne/aKCWaJeOYpKqZqs

[@syncrosimon]

Nicely explained, thanks🇬🇧🇬🇧🇬🇧

[@LakesideAutobody]

You're welcome :)

[@bessforman1773]

I wasn't sure if this about a strip club ....butts and laps. 🤔😁

[@ericwilkes238]

What would you suggest for a car top welding from? Back door to dack door

[@LakesideAutobody]

Not sure what you are asking - could you ask that again - different way?

[@joewest2560]

I've been welding seems like forever, bodywork... not so much. In fact I'd say I could count the times on one hand. So, a question, if your preference is to lap weld a portion, why not, weld a little short piece of welding rod to the middle of your patch and turn it on an angle and put it behind the parent metal and lap weld with the patch on the inside holding it by pulling on the welding rod while you tack? Admittedly not knowing a thing about body work, the thought of putting a patch on the outside of a repair would have never even entered my mind. Just seems like you would need do much more filler.

[@LakesideAutobody]

One reason is that irregular patches are welded as you go using the heat to mold the patch a little at a time. Another is that like shingles if you put the patch inside the seam opening would face up sort of holding any moisture (maybe). Last - I actually believe a thicker layer of filler is better because its more rigid than a thin layer. If the surface is prepared properly it doesn't matter how thick the filler is. Usually on a rust patch the thickest I think I ever used was maybe 3/8" .