What Guage of Steel to use for patch panels

I'm working on a 65 Plymouth Belvedere 1. What guage of steel should I use for patch work for the Rockers, inner cowl, and rear window lower corners and rails?

Thanks

Kevin

I think the sheetmetal seemed to be about 17 guage, even though i can only find 16 and 18 guage. 16 too thick and 18 too thin.

i use 18 ga.

Ok, thanks! I'll try to find 17ga, if I can't find it then I will have to go with 18 which should be fine.

Any special hardness of metal I should use? I don't want it too soft that it won't hold up but I don't want it so hard that it's not ply able.
Thanks

New replacement panels you can purchase for example from Dantes are 18 guage.

I would go with the 18.

most of the 18ga you find will be cold rolled and that will work fine.i use it all the time , sometimes i use 20 ga depending on what part it is for and how much strength it needs to have. i used 18ga to make a T bucket style body so it would be fine for patch panels. you can shape it a lot before it cracks.

I'm gonna buck the trend here and for some places suggest 16 or 14.

On a cowl, at the corners of the glass, or any area that has lots of compound curves, the extra thickness allows more metal to weld to, allows more grinding to get proper shape/profile, etc.

Thanks for all the insight guys, you've been a big help.

18ga seems more than sufficient especially if the floor plans are 18ga. But 16ga is food for thought, you make a good point as far as more material to work with. I can tig so welding isn't a problem, I just don't want any cracks 2 years after I get it painted.
Is 16ga a lot harder to work with as far as forming corners?

Thanks again guys.

Kevin

Just measure the piece your cutting out and replace it with the same gauge. Pretty simple IMO.