How to fill holes the right way when restoring a vehicle

Question:

I am restoring a 1954 Chevrolet pickup truck. The body is pretty much rust-free and straight, but previous owners have drilled a lot of holes here and there for various accessories including a big hole for a radio antenna. How can I weld them up without causing distortion in the metal?

Answer:

“Everything is easy if you have the « right tools,” someone once said, and that is true most of the time. The best tool for welding up holes in sheet metal is a copper paddle. You can get them from welding supply stores or from the Eastwood Company as I did, or you can make one yourself. Welding rod won't stick to copper because it is non-ferrous, so you can back up small holes with your paddle and just weld them up.

1. Place a piece of sheet metal of the same thickness and carbon content behind the hole and draw around it. Cut it out so there is approximately a /42" gap around the filler disk. 2. Hold the disk in place using a copper paddle for backing. Welding rod won't stick to copper. 3. Tack the disk in a couple of places, and then remove the paddle. 4. Tack weld in the disk alternating from one side of the disk to the other, and let it cool between tacks. Use a picking hammer to correct any warping. Keep tacking until the piece is completely welded in. 5, Use an angle grinder to grind the welding flat. Do not get the welded area so hot that it warps.

To make a paddle at home, get a piece of copper tubing 1 42" in diameter and about six inches long. You will also need a piece of wooden dowel (a bit of broomstick will do) to stick in one end to use as a handle. Heat the copper tubing using a propane torch until it glows, and then let it cool slowly. This will anneal the metal and make it more flexible so it won't crack while you are shaping it.

Now put all but about an inch of the pipe.in a smooth jaw vise and crush it flat. Remove the copper strip from the vise and use a body hammer to pound it perfectly flat. Round off the corners and bend the strip into a slight arc for working on gently curved surfaces. Finally, push the piece of dowel into the round end. and secure it with a wood screw if necessary.

Clean the area around the hole on both sides to bright metal. Place your copper paddle behind small holes and weld them up. Finish the job by grinding the welds flat.

To weld up a larger hole, put a piece of sheet metal of the same gauge and carbon content as the surrounding metal behind the hole and draw the outline of the hole on the sheet metal.

Cut the sheet metal to your outline and place it in the large hole. You may need to do a little trimming and filing to get it to fit so there is a slight gap (approximately 2") around the filler disk of sheet metal. Now put your copper paddle. in behind the hole and place the new disk on top of it so it is flush with the surrounding metal. Tack it into place in a couple of spots and then take away the paddle.

Next, spot-weld the disk in place one tack at a time going back and forth across the hole so as not to over-heat it and distort it. Keep going in this fashion, letting the metal cool slightly between tacks, until the disk is completely welded into place. Finish by grinding the weld flat using an angle grinder.

When the job is finished to your satisfaction, shoot a little rattle can paint on it to keep it from rusting if you are not going to be painting the part right away. Do this because welding carbonizes the metal and makes it more prone to corrosion.

If you want to order a copper paddle contact:

The Eastwood Company https://www.eastwood.com/