I have heard many times about using a piece of copper to put behind a hole when MIG welding so the weld doesn't stick to it.
I just it was a pride thing "Hey, I don't need any crutch to weld up a hole" http://www.chevelles.com/forum/smile.gif
Anyway, I had a hole that was rather large on the edge of a panel. I looked at a piece of scrape copper tubing on the floor and said, "what the heck". I smashed the tubing flat and used it. It works like frigging MAGIC! You can weld a hole an inch across! It is really neat, if you havn't tried it, do so.

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

Pretty cool MARTINSR, I have read about it too and figured it made sense and it HAD to work. Now that I see your post, now I'm gonna give it a try. Just a reminder to the younger crowd that copper dissipates heat rapidly, use a holding device. Thanks.

I'm glad you tried it. It's a tip that's helped me a bunch a times. Here's the reply I put in your "MIG welding bascis" post from a week or so ago.

posted 04-15-2002 09:39 PM
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Excellent post.
Another tip to add...
When welding thinner metal and wanting to fill in holes or "blow thru" is hold a piece of copper behind the weld. Rather than get frustrated that you "blew thru" take a step back, relax, place the copper against the backside (a partner is usually needed for stuff such as floor pans) and fill it in. The copper acts as a heat sink also. This tip may be more appropriate for beginners trying to find the right setting but even the best blow thru every now and then.

My brother even used an old cymbal from his drum set to do this.
Happy welding.
B~


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Brian
66 SS396 frame off WIP
"If things ain't going right, go back to sleep. Dreams will get ya there."

I used to work for a company that manufactured automated welding machines that could weld sheet stock as thin as .005. We used a 1/2" thick copper plate and ran a Tig torch on a ball screw controlled by a servo drive. It truely is amazing. These machines could make a weld that nearly disapeared when it was painted.

I have been thinking about this recently as I am going to have to take a fender to have some trim holes filled.

Anyone have any ideas on holding the copper to the panel during welding?

Thought about tape, but that would probably burn off. Thought about magnets, but the heat might effect them. A clamp would not work if the hole were in the center of the panel. Anyone?

Also, would the copper sheet allow you to stick weld a panel without blowing holes in it?

Thanks,

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Charles Perrell
cperrell@yahoo.com
65 malibu SS Convertible
283 2v powerglide

charles,

There are magnets that are made to hold welding material - but it might not help with copper - depending on your angle.

The best tool is the wide mouth vise-grips that have 3" clearance front to back and side to side - even though I'm sure you will get better suggestions...

Joe

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Joe Beyer
1969 Malibu Convertible (kinda)
http://www.chevelles.com/showroom/convtrailer.jpg
Home Page (http://JRBeyer.tripod.com/index.html)

<BLOCKQUOTE>quote:</font><HR>Originally posted by cperrell:
A clamp would not work if the hole were in the center of the panel. Anyone?

<HR></BLOCKQUOTE>

They sell vise-grip type clamps with long throat depths. I have 8", 10", and 12". I don't know if they make them any bigger.

They'd be deep enough for anything on my fenders. Maybe not something in the center of the hood, roof, or a trunk lid, but they're sufficient for most anything else.

Mine are cheapos. I think I paid $15 for the set at Harbor Freight.


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My Web Page (http://www.landry-family.com) (updated 3-19-02)

"America will endure!"

Chad Landry
TC Member #643
ACES Member #04556
'68 El Camino, 357, L31 Vortec heads, 700R4, 3.55 posi.

I am new to this board but have been mig welding all the holes in my '67 C10 after removing the trim. I use a copper penny behind mine...just maker sure it is not the recent copper coated kind...they weld to the body...LOL! I have used the welding fixture magnets ($2.99 at Harbor Freight) to hold the plug in place (large holes 0.5 inch diameter) or to hold the copper piece. You sometimes need a standoff the thickness of the copper backing material sit level. I have also used my mag tool base with a copper rod in it to back the hole. Whatever works.

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I found the key to the universe in the ignition of an old '67 C10...who'd thunk that's where it was left!!!!

What I used was a piece of copper pipe about a foot long. I smashed down the last inch of the pipe and used the other end as a handle. Worked great.

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

you can also use a brass hammer or pipe. i have a brass ball ping hammer with a fiberglass handle and it works great.