ok im tryin to fix my rust on my 1/4 panels. I cut all the old rust out and I got some questions. there are two holes and they are about 5 inches wide in one spot.
1- do I need to use anything to treat the bare metal before I paint it to prevent future rust?
2- what kind of metal should I weld in place of the rust and where would I get it?

THANKS!!

 

1-primer
2-sheet metal
3-a old refrigerator

 

ok but the factory dips cars into some kind of rust preventing ---- right? i just thought i might use some of that or w/e

 

my 911 was gavanized, but most cars are just primed

 

nice to see you are doing it right...i just used bondo...turned out well, but still needs some fine sanding, and real paint. but i redid it 3 times cause the rust kept coming back. but it was because i didnt sand or treat the rust...just bondoed right on it...haha. post some pics of progress and completion...i might be doing this in the spring if the rust comes back through winter. thanks.

 

yeah, audi's are galvanized, too

Just make sure you get the back side of the panel treated as well or it'll come through. You should probably use some body wax to fill the void and keep the thing from getting water in behind.

 

the reason why the rust keeps coming back is because moisure gets in form the backside of the panel. That needs to be sealed if not filler will not work , it will look fine for a month or so then it will blister and start to crack. Wap some POR on the back of it or some hippo linner. If ya got time , fiberglass em!

 

if you are going to fill make msure you use water-proof filler, and if you want to make sure no rust comes back use this ---- called Por-15, its supposed to stop rust forever, body men swear by it, i've never used it though. if you have any painting questions you can PM me. i just got done repainting a 1930 model A, so i learned a thing or two about rust.

 

also saabs and planes

 

most airplanes are aluminum or composite