If your not sure of the "coating" , in the area of welding you could remove the coating and apply weld thru primer.

Most auto parts stores like NAPA sell it in rattle cans, great for areas that need welding.

Resurrecting this thread.  I was wondering if people knew off hand what the gauge is on the Heritage wing panels and door skins.  I'm teaching myself to weld and wanted to practice on a similar gauge sheet metal before welding on the replacement panels themselves.

Also, do the replacement panels have some kind of protective coating that needs to be removed? What prevents them from rusting otherwise?

Thanks!

I just cut factory 1972 original rear panel and yes its 19g. To answer the previous comments on thin metal being used when welded together ?? I do agree but think how much more secure it can bond together when using in my case 16g. I finished one Side and its a night and day difference with no play. Unlike my other side with a heritage rear side floor panel being some what flimsy.

19 gauge seems to be factory.  Although I heard that the 59's were a thinner gauge. 

I would not assume thicker metal will greatly increase stiffness.   YOur stiffness is formed by all the bonded panels running different directions, and all the stampings in the shape.  A floor panel will flex when not installed, but once welded to everything, its should be very rigid.

 

What is the actual OEM panel thickness?

Some panel sections I make myself, but personally avoid going too thick to save the weight.  Most aftermarket stuff I've used seems to be linger at 20 gauge, some probably 22. 

Yeah . I agree with you. I did however noticed the heritage is 19 gauge as suppose to 22g non genuine . I'm redoing rear boot floor and decided to make my own of 16 g which is by far much better than heritage. I was just wondering if anyone out there has done the same. In my opinion car will be little heavier but much safesteady less flexing.

From recent repairs on our car, I can state that the heritage panels are much thicker and better metal than non-genuine aftermarket panels. Regrettably I did not have a micrometer or sheet metal gauge on me during the repairs, but the difference was such that 200 lb me could stand on the heritage panels with no noticeable flex, while the thin cheapie floor panel I could bend by hand!

 

 It seem to me that aftermarket panel are 22g . Can any of you experience mini guys fill me in on this. I'm planning to repair parts of the boot floor sides but I'm hesitant due to the thickness of this metal.

Has anyone decided on doing your own parts with thicker metal like a 16g. I would think its much safer, stiffer chassis less flexing.