I take and cut a piece to fit that area and weld it in like the rest of the panel

 

Its so small I cant really get it in there its about the size if 2 tooth pics side by side &half the length of one.

 

Something that size I just weld it shut. Make small little welds and let the previous weld completely cool naturally before making another weld. Fills like that take me a long time to do. I usually do them while I'm working on something else...I'll make a weld, go off and work on something else on the car, and come back and make another weld when I'm thinking about it.

 

Thanks right before I read this I did a search on here &found the same info pretty much,it works great!Thanks

 

Find a piece of scrap copper pipe and pound the end flat with a hammer. Hold it up behind your panel and weld the gap shut. The welding wire won't stick to copper. It works great!

 

Thanks Ill try that but Im welding patches in the bottom rockers&theres no way to access the back of em.

 

Old trick that works for me is to use pieces of coat hangers. I shape about 6 inches in the form to follow the lines of the panel and hold onto whats is left over. I place the formed piece in the gap and spot it in place and then form and insert the distance of the gap, spotting as I go. I then go back with wet rag in hand and continue spotting and cooling until the gap is filled. If you think it is getting too hot take a break and trade out the water for fresh, cool stuff.

 

I do the coat hanger thing at times. I always grind off the coating first, and will always go over it again welding hotter. Once I've established metal in the gap even though it's porous here and there I go for the biggest and lowest bead I can get.That way when you grind it down you're not in for surprise.

 

Old trick that works for me is to use pieces of coat hangers. I shape about 6 inches in the form to follow the lines of the panel and hold onto whats is left over. I place the formed piece in the gap and spot it in place and then form and insert the distance of the gap, spotting as I go. I then go back with wet rag in hand and continue spotting and cooling until the gap is filled. If you think it is getting too hot take a break and trade out the water for fresh, cool stuff.

you're much better off to let it cool naturally rather than shrink it with a cold rag.

 

you're much better off to let it cool naturally rather than shrink it with a cold rag.

I agree with that. If you are concerned about distortion, then slowly preheat the panel before welding, and after welding let it cool naturally.
Also the use of coat hanger for welding rod substitute is questionable because of the content of the coat hanger. It could leave the weld more prone to cracking. Any welding shop has cheap welding rod in various thicknesses

http://www.tempil.com/admin/files/Literature/Pre-Post_Weld Treatment.pdf

These are pages from a book, so you have to read each page from left to right, even if the first column starts under a picture

 

Hey guy's check this forum out. All you'll ever need to know about patching and more......

 

you're much better off to let it cool naturally rather than shrink it with a cold rag.

exactly. A wet rag will just force it to shrink too quickly and distort. I always just skip around and feel it by hand. I do sometimes blow on it but it's after it has almost cooled all the way down naturally. The tell all sign is how it looks when you grind on it. If you test the waters even slightly you'll have a hard time to making the weld disappear cause it will be slightly distorted really close to the weld. If you take your time you have no big warpage you can feel with your hand nor will you have that slight warpage that makes it hard for the edges of your weld to disappear when grinding. That's the key to making it disappear and having confidence that it's penetrated well. Obviously that includes a well penetrated weld.

 

Try that link again



http://www.metalmeet.com/forum/index.php

 

I just cool it with the blowgun.

 

I have used a blow gun to cool it and a wet rag. The wet rag always left behind moisture making for bad welding after. The blow gun is much better (this is my preferred way to shrink metal also) but you should not have to cool it either way if you take your time and spot weld a little at a time.

As far as the original question. I would just try to weld the gap shut and copper pipe does not have to be on the inside, it will still work you have it outside and weld to it. Or you can make a flange.