Hi- first post here. I'm nearing the end of my 30-year 1968 Porsche 912 restoration (OK, for 25 years of it I didn't do anything- "life got in the way"...). Metalwork done, epoxy prime applied, bodywork done.

Last fall I stripped all removables (doors, front fenders, hood, engine lid, front and rear bumpers) and sprayed them with epoxy (RM). This spring I stripped the body and sprayed it with epoxy, then did the bodywork (Rage Gold).

In the last week I scuffed everything with red pads. Monday I wiped everything down with damp cloths and then prep-sol. Yesterday I sprayed epoxy over all the bodywork and exposed metal, then a full coat on everything. Then 2-3 coats of primer-surfacer (Limco LP 800K).

Almost everything came out just fine- body, hood, engine lid, front bumper, one door, one fender. The rear bumpers showed quite a bit of cracking lines after the primer-surfacer dried. Also one very small section on one door and one fender. So I must have done something wrong in those areas. Any ideas? Thanks!

I assume I need to sand those areas down and respray.

My guess would be that you didn't allow enough flash time between coats of primer.

'68 Coronet R/T wrote:My guess would be that you didn't allow enough flash time between coats of primer.

i hear you, it took us 51 years to get this finished this ^^^ and maybe the epoxy, to quick to put the primer over the epoxy. flash times are very important and depend on temps and film thickness
Jay D.

Thanks for the replies guys (and Jay- beautiful car! I had a C coupe back in the 70s- another rusty restoration job).

Yeah, it seems like it has to be too soon recoating. Although the epoxy tech sheet says 5-10 minute flash/ 15-30 minutes before primer surfacer. I met that, but maybe I had the epoxy a little too thick in some spots so that extended the drying time?

The primer surfacer sheet said 5 minutes between coats, which I was well beyond. But again maybe I was laying it on too thick?

Come to think of it, the rear bumpers and rear plate were the only pieces hanging "vertically" and I may have moved the gun vertically rather than side-to-side which would have put more material down. Wrong. Add that to memory bank....

In any case I spot sanded the cracks today with 320 and was able to get 95% of them out. The rest go down into the epoxy and are pretty shallow at that point, so I think a few (careful) coats of primer-surfacer should fill them OK.

Thanks for the advice!

-Mike