The Stovebolt Site Forums The Shop Area Paint and Body Shop Low cost homemade welding tool.

We have all seen this tip mentioned on the forums, I thought I would put it in the "flesh." Weld won't stick to copper or brass. So, if you had a hole in metal you could temporarily put a piece of copper or brass behind the hole, weld into the edge of the hole with your MIG and literally fill the hole up without the weld falling thru. Remove the copper or brass and the back side will actually be as smooth as the surface of the copper or brass! It is a very neat trick and there are a bunch of tools you can buy for this purpose.

For example, I have a pair of "Vice grip" pliers with the copper backing built onto it. This is a very useful tool and like all tools, you just can't have enough. But it is very limited by the "throat" of the tool. If you have a hole out in the middle of a panel, it is worthless.

http://www.matcotools.com/ProductImages/pp23.jpg

One day I found myself needing a copper backing, I walked over to a pile of pipe cut off a piece about 9" long, smashed one end down real good with a hammer and a new tool was born. This is 1" diameter but it could be made from about any size. It has a handle so I can hold it up for a fast weld were even my clamp would have worked. Or I can reach around the back of panels to weld a hole out in the middle. Works like a charm. It was free because I had the pipe sitting there but one quick trip to the hardware store and a few bucks (or less) and you can make one too.

Brian

http://i200.photobucket.com/albums/aa167/BasicsofBasics/Copperpipe.jpg

http://i200.photobucket.com/albums/aa167/BasicsofBasics/Copperpipeend.jpg

That's a very good idea Brian. I've had that problem also, the hole to far away from the edge to get the copper/brass vice grips to it.

I am going to look for some copper pipe laying around the shop.

Thanks Brian

Great tip Brian ! i am gettin ready to fill the holes from an AD-ON antenna on my drivers side fender and i need to fill the original mirror mount holes on my 52 ....I am goin with a set of custome mirrors.
Thanks for the Great Advise !

I use those welding magnets to hold the flattened copper pipe in place - I'm new to this welding thing and I need both hands to steady the gun. It sure made smoothing the firewall easy.

You know what Desert, I forgot to mention that you can clamp this in place. There is a large enough area there that with a C clamp Vice grip you can grab it.

Brian

If I may I’d like to add this guys, Brian is correct in that pure copper is excellent for a back up with your mig or tig and small scrap pieces are readily available almost anywhere. How ever, when it comes to the copper alloys such as brass, which is alloyed with Zinc, and Bronze which is alloyed with tin, both of these alloys have a low melting point. I would not recommend using any of the copper alloys for a back up. Your almost guaranteeing that you are going to contaminate the weld puddle by using these as a back up heat sink.
Denny Graham
Sandwich, IL

I've always used a 1" "Tee" copper fitting as my back-up. One end I have mashed flat the other I have left round for repairs on the curvy parts. I put a "handle" in the remaining section. Most cases if I cannot reach it with a C-clamp, I can clamp the handle to something achieving the same end result.

MARTINSR,
Brian,
I love all your posts and have always listened and learned,when you have posted.
Thank You for the Expertise.
Just a suggestion but couldn,t you make a copper backup pad to fit on a big set of deep throat welding vise grips

LOL, YES you could! But that takes much more work than hammering a pipe. And quite honestly, I never thought of it!

Brian

If it's not practical to get to the back with any sort of a clamping device, then I resort to holding it with a bow. I have a bunch of different length bows that I made from a high carbon wire made from 1/8" and 1/4" wire. I got some of it out of over large head cable. It’s not one of the conductors but the tension wire that is used for supporting the cable in long spans. Of course any flat spring steel or high carbon wire will work. You don't want to use to small of a heat sink or it will push the parent metal out around the weld when it gets hot. Use a three or four sq.in. stamp to spread out the pressure applied by the bow to the back side.

As an example, In the top of my 1950, 3604 I have nine 1/4" holes in the top of the fender. They are arranged in three, three hole patterns where the flashing lights and siren were mounted when the truck belonged to the fire department. This is important, I hammer a flat stamp about three sq.in. so the curvature fits the back side of the fender nice and tight, then use one of my longer bows braced against the axle or frame to hold the heat sink in place while I tig weld the holes up. Then grind and hammer it flat, you might have to stretch it a bit or shrink it some. Generally it will shrink up the area around the welds and with some light hammer and dolly work, and a little picking you can stretch it back up to grade. I have yet to try a shrinking disk but might try one when I do the major body work this winter.
Denny Graham
Sandwich, IL

Brian...Had my hot water heater replaced yesterday and kept the old copper piping. Made a bunch of different configurations from it last night. Short pieces, long pieces, round pieces, some with handles, some without handles, some with different bends. Using it the way you mentioned is diffently the cats meow.

A bit of warning here guys. The copper is a heat sink for your weld jobs but go slow on your body panels none-the-less. If you pour the coal to the weld you can warp the panel causing you much work. So, do a little, take a beer break for the metal to cool then do some more.