The Stovebolt Site Forums The Shop Area Paint and Body Shop Copper Backing "Spoon"

I have some real small holes to weld up and saw that you can back the back-side of the hole with a copper plate temp while you weld. Eastwood sells this.

http://www.eastwoodco.com/jump.jsp?itemID=1181&itemType=PRODUCT

But would a piece of copper pipe, with a wood handle work just as well?

no need to get a spendy thing for that, find a piece of 1"+ copper pipe 12-18" long and flatten one end - don't need a handle - works a treat

Bill

I have used scraps of copper about 1/4" thick, and 1.5" x 3", works great, just clamp it behind the hole or crack.

Copper roofing is to thin, it will melt and fuse with the weld. Needs to have some thickness to dissipate the heat away from the weld immediately, or it melts.

Grigg

Thanks Guys, I figured the same thing, I got all sorts of scrap copper pipe laying aound the Water Plant, I'll get a piece in the morning.

I wonder how many of theose spoons does Eastwood sell a year?

That's what I used and it worked great. I made several different shapes for different applications, a whole shoebox full. I didn't put a wooden handle on any of em though.

If you buy a pair of c-clamp vise grips in the long size you can weld a pair of 1.5 flat washers between the jaws then take a piece of copper and line one of the washers with it. If I can figure out how to post a picture I'll take a few of the one I made, works great.

OK This is what I use works pretty slick, you can always modify to suit the job at hand.

http://i216.photobucket.com/albums/cc123/olcarguy52/Stuff%20Ive%20Made/workinaway054.jpg

http://i216.photobucket.com/albums/cc123/olcarguy52/Stuff%20Ive%20Made/workinaway053.jpg

http://i216.photobucket.com/albums/cc123/olcarguy52/Stuff%20Ive%20Made/workinaway047.jpg

Credit goes to Jim Bailey for this idea it's not mine

That's a neat tool and so simple too, like all the best ideas. Thanks for posting the images, another job to add to the "to do" list!

Stuart.

Slick tool thanks for posting the pictures.

Hi guys, thought I would share this little bit of information concerning copper flat bar source. If you check with people who do electrical work and change out large house panel boxes, or go to a scrap yard you can remove the copper busbar from the old electrical panels, Bussbars are solid copper bars approximately 1/4" thick x 1 to 1 1/2" wide and up to 2 ft long. Great for heat sheilds etc. Hopefully this can help fellow bolters.

Hey guys, ya don't need 1/4" thick copper buss bar as a heat sink to buck your welds and you don’t want it in most cases. Remember that copper has about the best heat transfer of any of the metals so just increasing the area will help pull the access heat away from the back side of your joint. You definitely want 100% penetration on you weld so you don’t want to pull to much heat from the area.
I've welded for most of my adult life and much of that time as an instrument welder at an accelerator laboratory. Heat sinking very thin materials is common practice and quite often used to match up heat transfer when welding thin to thick materials. When tig, gas or light mig welding even light .020" flashing available at any sheet metal shop or building supply is adequate and easy to form to the backside of your seam. The only place that you may need a thicker sink would be if you have a wide gap and you trying to mig weld it closed and even then the copper pluming fittings flattened out is usually more than enough.
Once your copper has been heated it will be annealed and soft enough that you will be able to form it by hand to fit flush against the backside of your joint.
Here is just one example of a .020” flashing used to back up a fender roll tear that was gas welded. Just a little additional tip for the new welders out there, by butting a same thickness stamp up against the end of the seam you can keep from melting away the edge. Start your weld at the edge and work in to the joint.
http://rides.webshots.com/photo/2736188780098611668ujExJC

A common problem area with the front of the rear fenders is where it is bolted to the running board. This area is often bent outward, stretched and torn around the edge of the boards. It was on mine and here is another area that was gas welded using a .020” copper-bucking sheet. To pull the lip back into shape and hold it while I welded the flanges I made maple form blocks: http://rides.webshots.com/photo/2077758280098611668etvvIN

Since this area is quite visible and is subject to some flexing, rather than use a plastic to fill the minor deviation due to the weld bead, it was cleaned and leaded. The lead filler, when properly tinned and applied is bonded to the base metal well enough that you could fold it in half and the lead still won’t separate from the base. Key here is clean, clean, clean: http://rides.webshots.com/photo/2163757360098611668YCEOkw
The finished lead filler, is an absolute minimum: http://rides.webshots.com/photo/2582800830098611668wtgreJ

Denny Graham
Sandwich, IL