I need to build a part for my 1935 Ford five-window coupe. It is a brace that attaches to the door pillar, the frame, the toeboard, and it welds to the cowl as well. How should I start this project? Do I need to make a mold using fiberglass or bondo? How many pieces would you make this out of? I could probably repair this one by replacing the rusted metal, but the other side is completely gone so I will have to build a complete one for sure.
San Antonio, TX
A: Yes, that’s a pretty complicated part, indeed! I’d suggest making the part from two pieces. I’ve drawn lines on your photo to help illustrate the approach I’d take; the purple lines are welded seams, and the yellow lines are bends. A pan and box brake would be ideal for this, especially in the areas where two flanges meet at an angle. There are a few more bends that will be required, and some additional details, such as beads and steps, which can be done with a beading machine. Some of the corner bends seem to have a tighter radius on one end, which changes to a “softer” radius at the other end. Bends like this are difficult to make on most brakes, but perhaps you can simplify the part somewhat, and use uniform bends throughout. If you really want to mimic the radius of the original bends, you can “bump” them on a brake; making a number of small closely spaced bends.
I don’t think it’s worth the time it would take to make a mold—most of your forming would be done off the mold anyway, and the best way to check the fit of the part is by trying it inside your car. You can make patterns from butcher paper to size the parts, and locate the bends and details.
I need to replace the bottoms of the cowl panels, doors, and quarter-panels on my Model A sedan. I purchased replacement panels, and I plan to install them by cutting the rusted areas away, then stepping the patch panels, so they will fit flush on the outside. I’ve done some of this work before, and the last time I got a lot of distortion when I MIG-welded the panels together. This time, I’m wondering if I can skip weld the panels together, then cover the joint with a thin layer of plastic filler. It seems to me that reducing the amount of welding should reduce the amount of distortion.
Via the Internet
A: Patch panels should be welded continuously. Even if the joint is covered with filler, as the metal moves with the expanding and contracting caused by temperature changes, any unwelded sections of the joint will “telegraph” through the filler and paint, and you’ll be faced with doing the whole job over again.
Yes, it’s true that more heat causes more distortion, but you still need to weld all joints continuously. One reasonable strategy is to weld a long joint as a series of “spots” or “tacks” and let the panel cool completely before adding more weld. While this is a tedious process, it will give you the least amount of distortion.
When you put a step in the under lapped patch panel, you are creating a trough inside the car where condensation can collect, and this can eventually cause the metal to rust. If you put the step in the body skin, then any condensation can “drain out” of the overlapped section, which is much safer in the long run.
I know that many people use overlapped joints because the fit-up of the panels is easier, but I’m still a fan of butt joints, which keeps everything the same thickness. This makes it easier to work the joint with a hammer and dolly to repair any distortion from welding.
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