Hi there to all. I have to do a rust repair to the inner wheel well at the rear passenger side. Seems like a common area of rust on a lot of these cars. Does anyone know what the gage the metal is there?

Thanks
Dave

 

I want to say it's 14 gauge. I would probably go to a salvage yard and cut a piece out of a thirdgen there, but without pictures, I can really only speculate.
DR.K.

 

20 gauge. The inner fender is a common rust area and new sheet metal is not available.

Depending on how bad it is, it can be repaired with multiple patches. It’s very tedious.

My restoration thread shows how I did it.

https://www.thirdgen.org/forums/memb...ns-am-gta.html

 

thanks man. I remeber your thread now from last year. Looking back at it, you have basically covered all my rust issues. Will definitely reference it more often. I was thinking 16 gauge for some of that metal in there but 20 gauge would be easier to work with. I also have a sheet of 18 guage that I've been using for some welding practice.

Thanks

Dave

 

So here is the area, im just basically in the process of getting the rust out. I prefer to keep that brace in the center if i can clean it up enough. The thread link noted above pretty much covers the repair very nicely. Dave

 

There is some 16 or 18 gauge for some of the structural metal, but the general sheet metal (floorpans, inner fender, firewall, etc.) are all 20 gauge. You could use 18 gauge, but it will be harder to shape and match the existing contours. 16 gauge would be very hard to work with other than a simple bend. Also, butt welding different thickness metal can be difficult as well. I got the sheet metal from an auto body supply store. It wasn't that expensive. I believe it was a 4'x4' sheet.

I have lots of additional photos that I didn't include in the thread. If you need a reference for a specific area, PM me and I will see if I have it.

 

There is likely rust underneath the brace. I would drill out the spot welds (with a spot weld drill bit) and take it off so you can get behind it and repair the metal. The brace is thicker metal and I was able to save them on both sides.

 

Spot welds and I are not friends but i just got started on it. BTW I will definitely send some questions your way. I have many and thanks help.

Dave

 

Yes, they can be a bear. Some people drill through both layers of metal with a regular drill bit (3/8" is usually close). That's pretty easy, but if you are keeping the base metal, then you have to patch that hole and that's even more work. I used a spot weld bit from Eastwood, but it's slow, takes a lot of force to make it cut and it dulls quickly. I went through 3 of them on the project and I sharpened them many times with a small hand file. One technique that worked well was to drill a very small pilot hole in the middle of the spot weld (all the way through both layers) and that lets the spot weld bit center better and it cuts better. The small hole is easy to weld up and grind flush. Once you get a group of spot welds cut through the first layer cut, then split the two layers with a hammer and chisel.

 

Wow, TransamGTA350. I had no idea it was that thin! No wonder it's so prone to rusting through. I've done some rust repair in the past, but never on a thirdgen. Cars don't really rust here in AZ, except maybe the battery tray, from acid. I've seen your rust repair thread before; nice work, and a good write up!
DR.K.

 

Thank you.
Yes, 20 gauge doesn't hold up to corrosion for very long, but other than that it's plenty thick for it's intended purpose. Any thicker would be hard to stamp into the required shapes and would add a lot of unnecessary weight.

I've been to AZ a number of times and I always find it cool to see 20 or 30 year old daily drivers still on the road. No rust, so as long as you can get replacement parts, they can stay on the road forever.

 

Yeah, that is cool. Lots of '70's and '80's cars and trucks around here. The sun is hard as hell, on the paint and the interiors, though.
DR.K.