BMW E30 Wheel Well Rust Repair & Underseal Removal | Welding Thin Metal With DIY Copper Block | 034

BMW E30 Wheel Well Rust Repair & Underseal Removal | Welding Thin Metal With A DIY Copper Block | 034
In this BMW E30 Build video, I turn my attention to the wheelwells which are the last area of the car I need to strip the underseal from. I'd already noticed a few ugly looking rust patches within the front wheel houses that needed attention so I was expecting to find a few rust holes to weld up.
Here's what I use in this video:
Clarke Weld MIG 150 TE Turbo: ebay.us/jbdfE8 (this is the newer version)
0.8 Welding Wire: ebay.us/eQWqWx
Argon/CO2 Welding Gas & Regulator: ebay.us/7BOngD
Angle Grinder Wire Brushes: ebay.us/sSJjtM
Dewalt Angle Grinder: ebay.us/CmsNuW
Safety Goggles: ebay.us/2Dvt5C
I got to work using an angle grinder with a wire brush on to strip the E30s underseal away and reveal what was underneath. It's worth noting that on the BMW E30 there is an additional factory coating on top of the typical BMW factory beige underseal and body colour spray. The additional coating is a black substance applied only in the wheel-wells to give them some extra protection from grit and stone chips.
After a few hours of grinding away at the underseal I had cleared the areas of rust and worked back to bare metal, and also resurfaced the larger solid areas of underseal ready to take on a new coating.
Continuing with my previous train of thought, I decided not to strip the wheelwells to bare metal and remove the factory e-coat. It's my belief that stripping away the original ecoat would only enable the chassis to rust more readily on the car. If something has been solid for 30 years, why disturb it and start it off rusting?
The areas of rust I feared would become rust holes turned out to be just areas of surface rust, the worst of it being some pitting. However in the passenger side wheel well I found that one of the studs which a plastic retainer for the fuel breather line screws onto had completely rusted away and needed replacing.
The worst of it however was a series of holes drilled into the top of the wheel well by a previous owner of the E30. These holes were drilled to fit an aftermarket alarm system, but this old system was no longer functioning so I ripped it out along with the wiring when I first got the car and it was driving.
Unfortunately, these holes were really poorly positioned to allow for future rust or grit to be flung into the engine bay, so I knew they needed to be sealed up. The good news was that I had great access to both the top and bottom side of this thin sheet steel, but the bad news is it was some of the thinnest sheet metal I'd ever needed to weld, and it was suffering from a little bit of pitting and surface rust too.
A previous commenter, and someone who clearly knows a lot more about how to weld thin sheet metal than I had informed me of the neat trick of using a copper block to aid with the welding of thin sheet steel.
I decided to try and fabricate my own small copper welding block DIY style with a length of old copper pipe which I cleaned up and hammered flat into a small copper welding block successfully.
How to use a copper welding block consists of pressing it against the back side of the thin sheet steel you're trying to weld, and it helps in these ways:
- It draws heat out of the thin steel, reducing the chance of warping
- It helps prevent blow-through by keeping the weld pool in place
- It prevents wire shoot-through when the weld current disconnects
I think this trick really is a game changer and combined with a simple MIG welder like my Clarke MIG150 machine you will be able to undertake all types of thin bodywork welding on the lower settings.
Needless to say, the repair went very well and once ground down with a flap disc the fix is almost invisible.
I've not got the areas sprayed up in etch primer to prevent flash rusting ready to apply my new underseal and seam sealer in a future video.
For more helpful how-to guides and restoration project logs, visit our blog: www.spannerras...
As an Amazon Associate, Ebay Partner and Awin Affiliate, we earn a small commission from qualifying purchases. Some of our links are affiliate links, and if you decide to purchase things through them, we earn a small commission. It costs you nothing but helps us to keep the content coming. Thanks for your support!
#bmwe30 #welding #rust #repair #restoration #bmw #e30

[@stephenbrown5844]

Fantastic video my friend. Really enjoyed it 😊❤🇬🇧

[@SPANNERRASH]

Cheers Stephen, glad you enjoyed it! 😃

[@clunk54]

Apparently lighter coloured cars got the black wheel-wells, darker colours were left body-colour. Hence my Dolphin grey E30 doesn't have the black paint whereas my other,Luxor beige one, does.

[@SPANNERRASH]

Hi Sid, thats very interesting, and kind of makes sense too as no doubt they were trying to save a few quid in the process. I've undersealed my E30 now, and gone for a grey Dinitrol stuff. Maybe I will go back and over-paint the wheel wells in black if I can see into them when the car is back together properly.

[@JaberRosmalen]

i can smell this through the screen.

[@SPANNERRASH]

I hope you aren't referring to my armpits. 🤣 Haha yeah, its always pretty unpleasant, anything to do with underseal. That goes for both applying it and removing it.

[@125sm3]

Removing underseal is such a tedious job to do , Have done it myself too many times to count lol. Glad you knew about the copper block trick . The BMW is coming along nicely. 👍

[@SPANNERRASH]

It's truly the worst! Glad I decided to avoid getting carried away and going full bare metal underneath. I'm fairly confident it's not necessary on this one. 🤞 The copper block is an absolute welding cheat code. I wish I'd known about that earlier. Thanks man

[@MrCeige85]

Such a tedious job. I used an air hammer/ chisel for the flatter sections of the body before finishing with the wire wheel. Definitely a shout if you’re doing the floor next. A joiners oscillating saw also works

[@SPANNERRASH]

Thats a nice idea for sure, I'm fearful about being destructive with a tool like an air chisel though, but maybe there's a technique to it. Cheers!

[@stampede720]

Every e30 I've ever seen had the factory paint color on the frame rails. The gray stuff there looks like it was added later, which is why it covers the brake line grommet (which looks original to me).

[@SPANNERRASH]

Ahh so you think the black was added later? I swear someone told me they came with black wheel wells from the factory but never been sure. It would definitely explain why the rubber grommet is covered. Thought that didn't look factory. Saying that, it is ancient underseal on them so I could believe it was original.

[@adamhaycroft5610]

Fantastic repairs. Very neat job welding that screw on, faced with similar I've fitted a rivet nut and locktighted an M5 thread in. Less work than your method but also doesn't arrive at the OEM looking result you have achieved, bravo. You can get (very expensive!) Stud spot welders too, but they are a very specialist tool beyond reasonable purchase for us chaps in our garages restoring these things at home.

[@SPANNERRASH]

Thank you! Using a rivnut converted to a rivstud sounds like a pretty good idea actually. I hadn't thought of that. Others have told me you can actually get rivstuds which sound better. I think I'd have looked down that route a bit more if I had more of them to replace. But seemed extreme when this worked so well for just one.

[@adamhaycroft5610]

@@SPANNERRASH I did not know rivstuds are a thing! Might well have to do some research and get me one of those!

[@PocketRocketGarage]

Loving your work! I’m doing a classic mini and we are both doing very similar work! Get yourself a clear visor from screwfix for grinding, keep up the good work dude! Kev

[@SPANNERRASH]

Awesome thank you mate! That sounds interesting I will check your channel out. A face guard is on my shopping list! 👍

[@chrisdovenbarger4329]

I really enjoy this build thanks

[@SPANNERRASH]

Thank you Chris, glad you're enjoying the vids! 👍

[@eberaladar5530]

Thank you very much for this new episode! Helps me a lot with my E30 project!

[@SPANNERRASH]

Great to hear! I hope your project is going well mate, hopefully faster than mine too. 😂

[@eberaladar5530]

@@SPANNERRASH Thank you! The quality is the matter not the speed.

[@SPANNERRASH]

@@eberaladar5530 A wise man to take your time and get it right.

[@nobiazcustomsinc5030]

Hey niccee!! its weird hearing my suggestion mentioned on a video lol but the copper block works a treat! such a headache saver on thin material. Glad it helped man!!

[@SPANNERRASH]

100%, really appreciate it dude, its something I'll be using going forward. Sorry I couldn't name you specifically, my recall wasn't that great on the day! 😂

[@nobiazcustomsinc5030]

@@SPANNERRASH Naa its all good just glad to make a fellow e30 restorers life easier!

[@clutsta]

Mate! I wouldn't be breathing in that dust if I were you!! Don't forget that mask! Loving the vids so far though! Your newest subscriber, Australia

[@SPANNERRASH]

Welcome aboard mate! And yes I agree it's very foolish to be rocking without a mask, crap coming out of my nose for a while after. I will take note. 😷

[@clutsta]

@SPANNERRASH i'm just taking a break from grinding a wheel arch of my own (N43W Mitsubishi Chariot) and sheltering from the 38° heat outside. Tbh, i'd rather it be cold where you are... the sweat that runs down the inside of goggles then into your eyes is bloody annoying. Must crack on tho! :P

[@SPANNERRASH]

@@clutsta Haha!! Damn I could not operate in 38 degree heat. I don't envy that at all, hope you get though it without getting heat stroke!

[@clutsta]

@@SPANNERRASH beer helps! :D

[@s4ms0n1t3]

For the missing stud you could use a rivsert with a thread, is how redish do it on their restorations (made this comment before you welded one on)

[@SPANNERRASH]

Cheers pal! That was my plan for if this more basic repair didn't work. If I'd needed to repair more studs I'd have definitely bought the kit. Maybe I'll pick one up in the future! 😁

[@Diamonds_Bulli_Ecke]

Hi Mate, please take a security mask and do not work without it. Protect your lungs. Great work! Thanks

[@SPANNERRASH]

Cheers mate! I should definitely take your advice on that, I know it's foolish of me not to. 👍

[@denguefever9489]

Hi mate before you paint the underside then underseal bare in mind wire wheels (used for the underseal removal) tend to polish the metal so it really needs to be keyed before the first coat of epoxy (or whatever you're using)

[@SPANNERRASH]

That's excellent advice, I actually have found that out the hard way a few times, it's one of the reasons I use etch primer as it etches the metal for maximum adhesion and then another coating can go on top. But I think keying the metal back up with a scotch pad is even better before applying it. I'll ensure I scuff up the bare surfaces and then etch prime before I go ahead and epoxy prime on top, then the new under seal. Hopefully, I can get that done soon, I'll make sure to shoot a vid when I do! 😃

[@xelad6159]

Hey mate, I replaced all my rotten threaded studs with riv nuts and will use bolts

[@SPANNERRASH]

I was tempted to do similar, but as only a couple needed replacing I decided to try this first, and I reckon it'll do the job! 😃

[@endrymetsmaa2668]

Nice job! For studs you used some kind of screws? What kind and what’s the thread size? Have to do the same on mine

[@SPANNERRASH]

Thank you! Yes I simply used a steel wood screw. I'm not certain of the actual size, as to be honest I picked it out of the box of loose miscellaneous screws every man has. 😂 I matched it up as close to the original stud as possible. As these studs are to retain plastic clips that screw on, it only needs to bite in, not be a specific size necessarily. I wasn't expecting this fix to work as well as it did. If you have lots to replace I'd recommend Rivnuts or Rivstuds as a superior fix. Hope that helps!

[@bobfrankish8883]

Just caught up on all your E30 vids and have really enjoyed them. Just some constructive comments. Were you to invest in a better quality welder, your work would be even better. I have used a Sealey Supermig 150 for all my cars, and it is OK, but if I had my time again I would definitely by an RTech unit. You probably know this, but if not, check out Dave's Garage channel, he is truly inspiring. Also, I don't know how you get to grips with 0.8mm wire on thin sheet, I'm sure your welds would be less blobby with 0.6mm, and the gas sounds far too high on the video sound, maybe not. I don't have the flow gauge, I just set it at the minimum flow to get nice clean welds, it is pretty expensive stuff. Going back to Dave, he uses straight CO2, much cheaper, and gets superb results with an RTech welder. I am 99% sure that the black underseal coating is not factory, certainly don't remember it on my E30, which was a 1987 and only 3 years old when I bought it so had had no interference whatsoever. Anyhow, you're doing a great job overall, so look forward to the next instalment.

[@SPANNERRASH]

Awesome thank you Bob, pleased to hear you're enjoying the vids. Interesting what you say about the welder. I had a terrible knackered Wolfweld welder before this and couldn't work out why I was just making a right mess. Getting this cheap but actually working Clarke welder was a step up. I've no doubt a higher quality machine would be another step again, so one day I will hopefully be able to justify that. I'll look Dave's Garage up, sounds like he has some good tricks for me to pick up. Yeah, a few people have mentioned that 0.6mm would be better, I really should take that advice and pick some up for thinner sheet metal welding. I'm using the 5% CO2/Argon mix gas at around 5-10L per minute which I thought was about right, do you think that's high? That's very interesting what you say about your 1987 E30's wheel wells not having the black underseal. Maybe mine has been given some love before now after all. Cheers!

[@selespeed3]

i have a bit of crack on the front left shock tower. how can i repair this? crack line surrounding the front shock tower.

[@SPANNERRASH]

A crack surrounding the front tower? Hmm that's not ideal! I have heard of this happening before as the towers aren't that strong, more often they dome slightly. I think the only option is to weld it, or if its really bad I think the whole tower panel can be welded in and replaced. You'd have to do a great job of this though because it would impact the alignment.

[@medievilassassin]

Great work mate , how did you like the seam sealer in your beard , ears and nose 😂 I took mine to bare metal and it was hideous along with the wire from the wheel stuck in my face 😂

[@SPANNERRASH]

Cheers Jason, I can tell you I've been finding seam sealer on my person for days 🤣 Bloody horrific stuff! And yeah I had that same problem with the wire wheel, the bristles fly off like darts, really stings! So glad I've removed what I planned to and can move forward. Don't know how you had the stamina for bare metal haha I can't wait to be working on the top side of this E30 rather than the underneath.

[@ronniewilson6597]

👍🏻😀

[@SPANNERRASH]

😁

[@Dennis-eh2vx]

Why don’t you ever wear a mask my friend, it’s almost suicidal what you were doing

[@SPANNERRASH]

I agree it is foolish not to, but I can confirm I'm alive and well! 😂 I certainly should take more care though, I just really struggle to work with so much PPE on, can't breathe or see when I do. I appreciate your concern though.

[@Aikaramba12]

Please use a mask. Think about your family and loved ones. Not good to breath this😢

[@SPANNERRASH]

Thanks for your concern, I should take your advice and be more careful! Luckily I survived this time! 😄

[@frundlemud]

No mask ! You may regret. Just a car. Put your health first.

[@SPANNERRASH]

Agreed, I should take more care!

[@Boatlife1964]

Wear a mask mate….you’ll thank yourself,in later life…believe me.

[@SPANNERRASH]

I should take your advice on that mate, the real nasty stuff is hopefully behind me now at least.