How to Weld a Steel Patch Using a Copper Backer – Kevin Caron

How to Weld a Steel Patch Using a Copper Backer – Kevin Caron

(Text on screen): How to Weld a Steel Patch Using a Copper Backer, Kevin Caron, The Voice: Hey, Kevin. What are you doing? Kevin Caron: Well, have you ever had a hole you had to fill in on a piece of metal? The Voice: Yeah? Kevin Caron: I’ll show you a little trick here. Here, let me just tack this together real quick and then I’ll show you something you can use. (welding) OK, so anytime you wind up with; you’ve got a little hole here, working on, like, a body panel, you’re working on a, you know, a little something. You’ve got a hole, you blow a hole in it, the fit isn’t quite good. Here’s a little trick you can use. Copper! It melts at a much higher temperature than steel does. So, as long as you have a piece that you can shape (this one’s a little thick to shape, but . . .) You have a piece that you can put behind your hole, and then clamp it on, like behind a body, or just right here on the table. Now you can come in and you can weld that steel, lay the fill right down inside that hole. Fill that hole all in. It’s not going to stick to the copper. It’s not going to blow through. You don’t have to fight and have this big glob and then you’ve got to go back and grind it all. Now, let me show you. (welding) See, I can start to fill this hole in here. You know, if you look at the back side, you can see it here. So I could come back in and grind this just a little bit. Or I could even come in with the TIG and get it just a little bit more on the back, just to fill in any little gaps that are there. But you can see how nice and smooth it came out on the back. No big bubble, no big glob to deal with or anything. And as for the copper, we just wound up with just a little burn mark on it. That’ll just buff right off, and use it again. Great, great thing to have around. You know; little different-sized sheets. You can get some of the thinner sheeting. I’ve even gone so far as to take a thin sheet of copper and a couple of rare earth magnets, and you can put one piece on the back side of the copper, the other piece on your steel side, and they’ll clamp together. When it’s so far in, you don’t have a clamp that you can reach in and do it with. Good thing to do; good thing to know. I’ll catch you next time. (Text on screen): Subscribe to See More Videos! See and hear more at


  1. Kevin, that's a "hole" lot of good info! Another of those little tricks that will benefit alot of us! Mary, somehow you always ask just what we would, such as "Hey Kevin, whatcha doin'?". I don't know how ya do it…

  2. @SkeluhtoR Well, Ok, the egg on my face is almost done.. You got a plate? I will be making some bacon in the next video….

  3. Great tip along with the magnets awesome I also noticed the protective leather hanging from the face mask, I'm going to do that ASAP Thanks

  4. @CBaughman I would say no. Keep your machine set for the metal you are working with. If you add more heat you run the risk of welding to the copper.

    Great question, thanks for posting…..

  5. @spelunkerd I just got my local scrap yard. You can also just pick up some copper water pipe and pound it flat.

  6. Hi Kevin right now i am working on a sculpture of a robotic arm. i will have a video of it posted soon. thanks a million from Bob in seattle

  7. @1tusk4nicks That bright red glow coming from my computer is me blushing.

    Thank you for these kind words. I always try to remember the difference between a pat on the back and a kick in butt is a foot.

  8. I got mine at the local scrap yard. They have a copper building in the corner of the yard. You might check with your local scrap yard or a new steel yard. You can also get it on line but shipping with get you in the shorts….

  9. FYI.  Steel has a higher melting temperature ( 2600 – 2800 F) than copper (1983 F).  Copper is a good conductor of heat, which is why it doesn't melt when used as a backer.  I find your videos very informative and you are a better welder than I will ever be. 

  10. Get a piece of copper bar stock about 3/16 thick x 1.5 wide and what ever length you want. On each side of copper bar 1/4in from the edge drill a 1/8in hole every 3 or 4 in. Then Lay the copper over the seam to be welded and using it as a template take a 1/8th drill and transfer the holes one at a time. After you drill the first hole put a 1/8 cleco in it to hold it then the next and so on. Now your holes on the bar stock and floor pans or body panel what ever match perfect. Then you remove the clecos and put the bar stock on the back side of seam to be welded. Now place the clecos to hold it in place. This will pull the sheet metal down real nice and tight so you get a great weld. After repair is made remove the clecos and plate. Just a little tack with the mig to fill the 1/8 holes and you are done. Then your plate can be used over and over. If you not sure what a clecos is. Then look them up. Basically it is a temporary rivet. A special set of players to apply them. I think I purchased 50 of them and the players off eBay for $35. I know I should of made a video instead of rambling. I hope o explained enough you can follow. I sure Kevin might be able to follow. It sounds a lot harder than it is. If anyone has any questions I try to help.

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