I was slowly working a small dent out of my roof about 4" in diameter with a hammer and dolly. I managed to pop it outward convex, i pressed down again to straighten it out and it poped back in concave i can press it back out and make it concave to match the roof with my hand. so the question is do i leave it concave and use body filler? or make it convex and use filler? i dont want it to pop up or down. ?

 

You got yourself an oilcan dent. What has happend is the metal stretched. You need to use a shrinking hammer and work it back to normal. If you don't, temperature changes will cause any filler to pop out over time.

 

oil can dent so i can use a acetelyne torch and shrink it back to normal or do i have to use a hammer and work with it?

 

You can use a torch if you have real skills. A torch can cause more damage than it repairs. On the roof any distortion is hard to fix and easy to see.

 

Well il give it a shot i cant afford to have my paint job ruined. il just heat it up slowly and pop it back with a wet rag and try to hammer and dolly it back smooth.

 

try shrinking it with a shrinking hammer or a hammer with a pick end

 

I agree with rmodel, but I would strongly prefer using a good shrinking dolly or hammer rather than a pick, but you have to use what you have on hand. The new shrinking dollies and hammers I've seen have a bunch of small pimples. The old ones have some larger serrations. The old ones with the serrations seem to work much better.

The torch approach is risky.

Good luck,