Thread: Fab of bottom door panels for 1937 Buick

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Originally Posted by Mutt's37Buick

Attached is a picture of the back of the door.
The rust goes about 5 inches up the door. I have bee using butt welds for my repairs.
1) For the door bottom, would I be better off using a flanger and creating an overlapping flange at the top of the 5" panel?

If you've been using butt welds thus far, don't stop now. That's the correct method to use. Regardless of the dis-information you can find online regarding using flanges, especially manufacturers selling the flanging tools claiming what an advantage they are for installing panels and the fact that replacement panels come with them, flanges are not a good solution for a sheet metal weld repair.

Sure, flanges can be a crutch for someone who is just learning to weld, but you are adding rust issues/moisture trap, and more importantly the single panel thickness on one side of the weld expands faster in sunlight than two panel thicknesses on the other side. So despite any filler and paint covering the flange seam, the repeated differing expansion and contraction rates will eventually leave a ghost line in your paint finish right at the seam. Just like a wart on the end of a nose, everyone will see it and know exactly where and how the repair was done. Any deformity from the welding process also becomes near impossible to planish out the defects given the multiple layers. IMO is detracts from the value of the car as it is not the correct way to repair. You hear guys saying it's OK to use on floor pans as nobody will see them. I disagree as this is the perfect scenario to practice butt welding to improve your methods, so when you are on a panel that really matters, you feel more comfortable and are more skilled doing it. Keep up with your butt welds...

Flanged joints can create 'ghost lines' which you won't have using a butt weld.

Welded some more TIG coupons this evening to show results with different weld placement, so I decided to do some samples that mimicked various body shape types.


First, we have a flat version, this would simulate the flat area at the bottom of a door skin...





The second panel has more crown, such as toward the top of a quarter/door skin....





Comparing the two...





Next, we have a repair piece that is joined at the beltline bead...





The flat area distorts quite a bit... Normally we would planish the weld after cooling to remove this distortion, but here it was left to better compare distortion amounts..








Looking at the three samples, the flat one moves/distorts the most. The low crown a bit less, the beltline bead even less..





This helps to show the benefit of weld seam locations, we should select anything but the low crown/flat areas if at all possible..

Thanks for posting these examples. I'm having the most trouble seeing how to form the hem that would hold the 5" panel to the side panels at the end. First picture is the same door on car. Second picture is the end of the door (from back) showing the curve to the bottom. Notice the folded over hem that captures the side piece. The hem is very similar to a folded over hem that holds more modern door skins across bottom of door frames. The difference is the hem goes around that .875 radius curve. This folded hem would be on the end of the 5" tall panel.
I'm having trouble seeing how to form this hem around the radius.
Thanks