I have sprayed some rattle can primer on the car after stripping the paint and sanding with 80 grit on a DA sander. I need to feather out some existing PF from previous repairs. Can I apply new PF over the primer that I have applied or do I need to sand that off first ? I will then be spraying the entire car with Sherwin-Williams Ultra-Fill II (2 part) Urethane Primer/Surfacer. Does this sound like a good plan ? Thanks

i would sand it off also grind out old filler and do it again its worth the extra work.

Rattle can primer over an entire car??????

Originally posted by DG:
Rattle can primer over an entire car?????? I am stripping one section of the car at a time and when I complete that area/panel, I am sanding and putting a temporary coat of rattle can primer over the bare metal before I continue to the next section. After sanding that primer off in a few weeks, I will be spraying the entire car with Sherwin-Williams Ultra-Fill II (2 part) Urethane Primer/Surfacer. Does this sound like a good idea :confused:

doesn't rattle can primer still hold moisture against the metal underneath it? thought that stuff was still moisture permeable.

ALWAYS use etching primer over bare steel. Sherwin Williams makes an excellent rattle can version of this that I wish I could provide the P/N. Like marinablue67 mentions, most primers (including etching primers) are not moisture resistant and if it sits outside could be a serious problem. Don't underestimate the importance of etching primer, I don't think the Ultra-Fill2 is recommended to use over bare steel, but I've been wrong before. Ask your supplier about the primer I mentioned, you wouldn't have to sand it off!

Originally posted by eduardo69chevelle:
ALWAYS use etching primer over bare steel. Sherwin Williams makes an excellent rattle can version of this that I wish I could provide the P/N. Like marinablue67 mentions, most primers (including etching primers) are not moisture resistant and if it sits outside could be a serious problem. Don't underestimate the importance of etching primer, I don't think the Ultra-Fill2 is recommended to use over bare steel, but I've been wrong before. Ask your supplier about the primer I mentioned, you wouldn't have to sand it off! I will get some etching primer this weekend from my paint supplier (PPG). Will I be able to make use of this Sherwin Williams Ultra Fill at any point before painting and is there any type of primer I can spray on the car and leave for an extended period of time (6 months) before painting that will keep the rust away? :rolleyes:

Thanks everybody ;)