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fabricating patch for 26 coupe
Posted: Thu Dec 09, 2021 11:44 pm
by varmint
So, the rust ate up pretty high all around the bottom. This is left side bottom, between the driver's door ans the wheel well. The green etch primer is a stainless steel patch panel that I made some time ago, attached by stainless wire flux core welding. I am now just getting to the next piece, also stainless. The patch panels that I bought were too small for the damage from rot and I found some paper towel dispensers from a men's rest room that were being replaced during a remodel,
What I don't know is the taper along the wheel well edge. How far do I need to cut this thing back before I weld? I put calipers there to give an idea of what I am requesting help for.

- 26coupe wheel well 1

- 26coupe wheel well 2

- 26coupe wheel well 3
...and thanks guys.
Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 8:00 am
by Jerry VanOoteghem
I think you may have trouble getting paint to stick to stainless steel... Maybe with epoxy finishes it might work??
How much does the other end of the patch taper? I'd follow that contour.
Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 8:39 am
by TXGOAT2
Integrating a stainless steel repair section into a plain steel body may prove to be more trouble than it's worth. Getting paint or filler to adhere to it may be difficult, and it can be very prone to cracking. I'd think it would be difficult to shape, too, and may have different thermal expansion characteristics than plain steel and probably has different flex rates when subjected the the forces acting on a car body. Joining dissimilar metals might cause corrosion issues. I think GM built a few show cars with a stainless steel top, and the DeLorean car used it extensively. From Delorean Wiki: //////////////////////////////////////////////////////////////////////
......"The stainless steel panels are not indestructible and some seemingly harmless acts may result in severe damage to the finish. Contrary to popular belief, SOS pads or steel wool damages the stainless steel. Steel wool leaves small metal particles (from the steel wool) embedded in the grain of the stainless steel which rusts -- giving the impression that the stainless steel is rusting. Also metal abrasives (SOS pads) act as reducing agents, chemically reacting with the outer oxidation layer of the stainless panels and destroying some of their stainless properties. Iron compounds in general react with the steel -- bleeding on your car or leaving a slice of bologne on your hood may cause persistent blemishes that are difficult or impossible to remove. Although very resistant to nitric acid, SS304 is not very resistant to phosphoric and some other acids."........
Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 10:22 am
by John kuehn
If you decide to use another piece of sheet metal you can buy pieces of random sizes at Ace hardware and occasionally at Tractor supply stores.
Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 10:45 am
by John Codman
Some alloys of Stainless steel can and will rust. Generally speaking, the more Chromium in the alloy, the less it will rust. I concur with those who say that joining dissimilar metals isn't the best idea. I can understand why yhe OP wants to use stainless, but I would use regular steel patches and not drive it when salt might be present on the roads.
Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 11:39 am
by Norman Kling
How do you plan to attach it to the existing metal? I am not sure you can weld or braze stainless or if you can weld it what will you use to bond to the existing metal. A good patch should be welded into place and ground to be as smooth as possible and then filled with a good filler to fill any low points then sanded smooth and then primed with enough primer to sand and make it look so smooth to be undetectable. If you can't get it tight, water will get in from rain or car washing or any splash.
Norm
Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 1:00 pm
by varmint
Wow, so more comments about the stainless steel than the taper question.
The bottom one inch all around the rear half of the body's sub-frame is stainless steel. It is welded to plain steel square tube, since I had to recreate the entire sub-frame as half the parts were made of unobtainium. Etch primer is already sticking for years to existing SS patches.
https://www.amazon.com/Blue-Demon-308LF ... 00G5GHA7E/
Blue Demon 308LFC-O X .035 X 1# Spool stainless steel flux cored gasless welding wire
I have been using this stuff for a couple of years and have no problem with adhering plain steel to stainless steel.
The other side of the wheel well is the B-pillar. The bottom of the B-pillar was also rusted away and I had to recreate it. So, it's not a good guide. The doors were rusted and do not have a definite form to follow either, as they need repair too. The patch panels have a 1/2" overlap, thus not worried about rain running down the side.
Anyway the real question is how much I need to cut back on the wheel well as it tapers to the bottom edge.
Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 2:41 pm
by Bryant
I tried to measure my 26 and it is very difficult with a tape measure. But it looks to between 7/8 and 1 inch. Then I took a piece of cardboard paper and bent it into place down in the channel. Pulled it out and it measures 1 inch on the nose. Not an exact science. But close

Re: fabricating patch for 26 coupe
Posted: Fri Dec 10, 2021 3:56 pm
by Herb Iffrig
Go to youtube and look up Fitzee's Fabrications. He has many videos there. You will see how to do a remarkable job repairing rusted sheet metal. He has a good way of showing you how to do it with simple tools.
Re: fabricating patch for 26 coupe
Posted: Sat Dec 11, 2021 8:46 pm
by varmint
Bryant, Thanks!
I trimmed the inner steel to 3/4" and the top patch panel to 1", welding them in place today. Now all I have to do is remember 1" when I do the other side.

- bottom of the car body after hauling the Model T
- rust.jpg (33.27 KiB) Viewed 2679 times
Herb,
Thanks for the YT channel, looks like the sort of thing wife and I are into watching.
There is no repairing the bottom pieces as they were literally swept into a box.
I have an English wheel, bead roller. Made an anvil, and a brake press. What I don't have are measurements.
Re: fabricating patch for 26 coupe
Posted: Sun Jan 02, 2022 6:25 am
by varmint
Thanks again.
Here are the four patch panels, all were put in and need dolly work.

- Left rear wheel well

- Front left cowl

- Right rear wheel well
This shows the bead rolling that went into it.

- front right cowl
Instead of drilling holes in the old body and plug welding to the overlap flap behind outside edges, I merely pointed the wire feed at the body until it melted a hole in the plain steel and hit the stainless behind it. I had a heat sink behind the stainless patch. Those are not shown here.
Re: fabricating patch for 26 coupe
Posted: Sun Jan 02, 2022 9:22 am
by John kuehn
When there’s a will there’s a way. Good job varmint! Being a maintenance mechanic / welder for many years and when I saw your post I was wondering how you would do it. I thought welding the panels together would work. It’s something that’s not commonly done.
When prime and painting the panel I would imagine it would be a good idea to sand off the slick finish of the stainless to help the paint to stick.
Interesting to be sure.