How to mig weld a flex pipe on a car

In this episode we Mig weld in a flex pipe on a Honda accord. Not something I really like doing, but I did it for the greater good of helping you guys learn 😃
0:00:00 Intro
0:00:54 Solving the worlds problems
0:04:02 The offender
0:04:50 Saw it out
0:05:58 The setup
0:07:57 Welder setup
0:13:08 Let’s weld
0:15:30 Conclusion

[@Jeff-rk8hq]

I can’t tell you how much you say I found out of your videos, Greg I genuinely appreciate your efforts and can’t tell you how much you have taught me over this past yr

[@makingmistakeswithgreg]

Thanks for the kind words and i put the effort in to help people out so they can fix things too 😀. I enjoy helping people and making videos, glad to know it made a difference for you.

[@JeffWok]

Great videos Greg. I really like the way you work and explain.

[@AXNJXN1]

Excellent work Greg and thanks for covering down on the deets, super helpful!

[@MK-xn6qx]

Good job Greg. Who cares about buttons or finess in welding. I believe in "as long as it gets the job done"

[@Cptnbond]

Hi Greg, I always learn something new after watching how you to tackled each broken metal repair job. Cheers.

[@scrapperstacker8629]

Great video this is exactly the type of welding that I do.

[@makingmistakeswithgreg]

It’s a tough job. It’s so easy to weld clean material on a work bench. Welding on a car with poor access, poor visibility, in position, and on poor quality (thin) material takes a lot of skill, and patience lol.

[@Stewartlearnstoweld]

Yeah I love my little flux core welder it’s small portable and the gun is small

[@aros007z]

Awesomeness

[@MathewPollard-vj4uq]

Great point on figuring out why something broke and addressing that before "fixing" it. Replaced three motor mounts on my Lexus es350 and am here because the flex pipe is broken.

[@makingmistakeswithgreg]

I hope the motor mounts weren’t a pita to do on that car. No doubt bad mounts break flex pipes. After redoing a couple new flex pipes that broke I realized it pays to look at how much the engine moves before assuming the pipe was just old and that’s why it failed 😅.

[@MathewPollard-vj4uq]

Motor mounts on the ES330 (it's a fancy Camry) weren't bad to do. But the point of figuring out why something failed before slapping in a new part or repair applies to lots of things. I'm "this close" to buying a welder so I can do this repair myself.@@makingmistakeswithgreg

[@makingmistakeswithgreg]

@@MathewPollard-vj4uq well I can tell you the harbor freight titanium 125 for 170$ or less with coupon can definitely do the job, and anything better would be even easier. I won’t sugar coat it though, welding exhaust sucks. It has a lot of angle changes, uphill welds (which is very easy to blow holes) and you’re welding on paper thin material (which sucks in general). If you practice a bit on the same pipe size it’s doable with minimal skill. You must run hot enough to get proper fusion, and you must move slow enough to deposit metal. If you can do slip fits on the flex pipe it’s 5x as easy as a butt weld. If you only had stick welding as a option I would say no way, but flux core wire is doable. Gas shielded mig is actually harder to weld exhaust with because of the uphill welds.

[@ls2005019227]

Welding exhaust under a vehicle (without a lift) is a complete PITA.....but mig is significantly more convenient than tig (& running a foot control). My helmet always seems to be wrong/fall off. Similar to welding on the bottom of an aluminum boat that's still on the trailer. Great job!

[@makingmistakeswithgreg]

Never done a bottom of a boat, that’s got to be terrible on a trailer lol. I have heard of guys using a “tig button” to control amperage without a foot pedal. Closest thing I ever did was fix the frame on a enclosed trailer, the axles pushed through the main beams. Took me 8 hours and I couldn’t stand up straight for two days after. No more of that for me lol.

[@mkearn724]

I’ve always known the leather masks/hoods to be referred to as monkey hood. Not exactly sure why but in the field that’s what a soft hood is called. Those autodark masks are pretty slick. I have a Miller that I use when I have to get in tight spots like column webs. I e been in a bind before where I removed my 2x4 auto lens and taped clear lens covers on it and just held it in front of my eyes. I e never been a fan of exhaust work nor welding it while under the vehicle. That’s a good catch with the motor mount and not just welding the exhaust for a temporary fix

[@makingmistakeswithgreg]

Haha a monkey hood, I never heard that. Youre not missing anything on welding exhaust that’s for sure. I can build real nice tig welded header on a bench and enjoy it, but welding under a car is a frustrating time lol. Especially in this state where everything is rusty beyond belief.

[@DG-fn7qg]

Glad I ran across your video. I was going to ask you about welding on vehicles and you beat me to it! Do you disconnect the battery when you weld on vehicles? Thanks for posting!

[@makingmistakeswithgreg]

Generally speaking I don’t but it won’t hurt. Disconnecting the ECU (if easy) if it’s by where I am welding I will do though. The most important thing with vehicles is having a really good ground really close to where you are welding at 😀

[@DG-fn7qg]

@@makingmistakeswithgreg So much information out there, don't know what to believe. I do however trust your judgment. Have a great weekend, and thanks for responding!

[@beyondmiddleagedman7240]

This is why I gas weld. Exhaust systems. But everything being SS now ups the ante a might.

[@makingmistakeswithgreg]

Yeah, I am pretty sure parts of the factory exhaust were 409 stainless on that Honda. Everything I own is aluminized steel still.

[@TheForerunner117]

When a guy tells you to go out and buy the welder that you already have😅 makes me feel less worried about this flex pipe I gotta go after here. Welding the top part is what I’ve been looking for tips and tricks on. Seen people recommend using a hole saw on the bottom, welding it from the inside and welding the disc back on lol…

[@makingmistakeswithgreg]

Haha I have never heard of the holesaw trick, that definitely could work. The best way to weld car exhaust that I have found is a “swan neck” flexible Mig gun with flux core wire. By not having a nozzle on it and the flex neck you can get in anywhere. The top of the pipe is a absolute bastard to get at in some cases and the flex head/no nozzle is a life saver.

[@TheForerunner117]

@@makingmistakeswithgreg I’m wondering if a flex boy is obtainable for the titanium 125. Sounds like the acetylene welder with a bent piece of rod is the absolute easiest old school way to do her. I figure I could drop the exhaust hangers on this 300$ Malibu I’m about to buy and flip, but it probably wont help me much on the down pipe from the manifold side, lol. One of them pairs of auto darkening glasses on Amazon are looking pretty cute right about now 😂

[@randonloebsolvingproblems4421]

What steps/knowledge to avoid sparks near the gas tank?

[@beyondmiddleagedman7240]

If you can smell gas, don't weld there. (Something is loose or leaking). Otherwise, just weld it. If it is worrisome, hold a piece of tin flashing between your work and the tank.

[@makingmistakeswithgreg]

I totally agree with @beyondmiddleagedman7240. I tend to not weld near gas tanks in general but if I do I have fiberglass fire blankets that I put up to keep the sparks off the tank. If you can smell fuel you definitely need to address that first lol.

[@jcvazz756]

You didnt need to unplug the battery?

[@makingmistakeswithgreg]

On exhaust its generally not a big issue. The book answer is to unplug the battery, because it’s not worth risking the potential damage to the computer or the wiring. The funny thing is with the way cars are wired, disconnecting the battery will not prevent wires from being used as part of a circuit for welding. It just reduces the chance of them being used. If you have your ground clamp near where you’re welding, and it’s a solid connection, I wouldn’t worry too much at the amperage levels you weld exhaust at. If you try to run 200+ amps and weld near a computer, well you sure could end up frying some things.

[@TheOneAndOnlySame]

MIG is 100% argon. Argon mixes or straight C02 are MAG.

[@makingmistakeswithgreg]

You are probably in another country besides the USA. Although you are technically correct, (the only wire process that uses 100% inert gas is aluminum, which is done with spray), universally MAG (if the term is ever used in the USA) is generally only used for spray arc gasses that contain oxygen, or other blends where the purpose of the active gas is to increase heat input and not just stabilize the arc. Universally “Mig” is used to define the short circuit process, and it is still called that by Lincoln electric, miller, and virtually every school in the country (outside of GMAW). What you must remember is MIG isn’t necessarily incorrect for c10 or c25, they are more inert than active gasses, and the term is widely accepted in the states. So although it may be somewhat “incorrect” in the country you’re from, it’s not necessarily wrong or incorrect in general. Just as MMA vs SMAW isn’t a “right or wrong” situation, they are two commonly understood terms that work. Nothing wrong with that.

[@TheOneAndOnlySame]

@@makingmistakeswithgreg Ok, I see. Didn't know it was the norm in the usa to call any GMAW "mig" I learned something 👍

[@thegarbagegladiators4735]

Hit the thumbs up before 5 seconds go on .

[@al-bp1pi]

It can be age cause it to break

[@stovolbelinche3178]

youtube is being stupid its genral greivous got an qustion about some stick welding sticks i need a high streanth decent pentration decent depset innother word a 70 rod with some good pentraction cuz i need fix my home 4 ton bench vice well rated for 4 tons of presure and need it to be realy strong and the steel is i think high carbon and the rod needs to be on AC ahh amd if it an't chevy or ford its scrap i have an 1986 chevy square body 454 v8

[@makingmistakeswithgreg]

For what your looking at if you are welding in the flat position 7024 would be a rod I would definitely consider. In my testing it penetrates better than 7014, and is far easier to weld than 7018. 7024 will run on AC. Otherwise 7018 AC rods will work, but I have found many don’t seem to run the best. Many non ac rods will work on AC. Now if the material has high carbon content I would look for some nickel 55 rods. Preheat the part to 400 degrees and run the nickel 55 rod. The nickel will absorb the carbon and not become brittle, which will prevent cracking. The preheat will prevent fast shrinkage and subsequent weld cracking as well.

[@stovolbelinche3178]

@@makingmistakeswithgreg thank you sooo much this vice hase been in the famly since like 1898 when carbon steel was discoverd and it like i dont know how vauble it is to me if i could send you some money just for this info i would you will go down in my famly history as "greg the famly heirloom savior" i dont know how much more i could show my "appreciation" and i hade to look that word up but yea the point is your a very important guy now

[@makingmistakeswithgreg]

@@stovolbelinche3178 no problem. I went cast iron all the time and it either comes down to preheat to 400 (whole thing is heated to 400) and weld with nickel 55 or 99 stick rods, or braze it with silicon bronze/aluminum bronze. Nickel is a better repair, but sometimes it’s not a option. The big thing is carbon absorption. When that carbon absorbs into the molten metal the weld will become so hard you can’t even file it. Very high probability of a crack in that case. Nickel doesn’t become brittle when it absorbs carbon, so it’s a life saver. In a little bit I will have a video out on welding cast iron and a ton of tips on how to do it 😀.

[@stovolbelinche3178]

@@makingmistakeswithgreg yay new video also hows the move going ? also i just got done smoking my pipe then i strik an ark the 321 power goes out so back to smoking a pipe or cigar and yes i know it will kill me by cancer but hey welding is slowy killing me to by cancer so MAXIMAN LUNG CANCER it like one pipe a day tho