Is it ok to let epoxy primer sit without topcoat?

[justasquid]

I am just curious as to how long a car can sit in epoxy primer without being painted? I am planning on starting the metal work on my car and will need to cover the bare metal. Unfortunately, I wont be able to paint it for sometime after the body work has been completed. I am hoping that I can just rough the primer up when it comes time to paint.

Is it ok to let the primer sit without any paint for an extented time period? If so, how long is too long?

I have painted around a dozen cars and feel confidant enough painting my camaro. The thing I've never done is a slow restoration. Every car I've ever done has been a weekend paint job, nothing that has ever sat. I want to be able to do the body work and protect the body work as I am doing this project over a few year period.

My goal is to lay the car in expoxy primer this year, and hopefully paint next summer, so it will sit through a winter. It will be in an enclosed garage, but some moisture will more than likely still get in as its not an air tight garage, but the doors wont ever be open in the winter.

thanks,

[hotrdblder]

depending on brand, yes applied at a certain mil thickness you will have corrosion and weather protection, then when working on it again, sand the epoxy with 80 or 120 grit

[justasquid]

thanks for the quick reply. I really appreciate how fast this board is with its memebers and their suggestions. I've always gotten fast answers...this sites memebers are awesome.

I wasnt thinking 80-120 grit. thats certainly a harsher grit than I was thinking. I was thinking 320 or maybe 400. is this not harsh enough to get the new coat to stick over the epoxy?

I'm planning on using ppg, but if anyone has other suggestions, I'll be glad to hear any other suggestions.

thanks again,

[Restomod]

With it being inside you should be fine, the 120 is ok its tough stuff after it has set up good.

[hotrdblder]

epoxy is also suppose to be top coated with a urethane primer, that said i would finish body work in 180 then urethane prime, block sand

[justasquid]

thanks for the replys. This info sets my mind at ease. Also, thank you guys for the info on the sanding. I surely would have used the wrong grit.

thanks again,

[Paint God]

Like someone said you are going to want to prime and block it before paint so I would suggest this in your case if you want to use PPG.


Finish body work in 150 grit
Spray one nice wet coat of DP Epoxy (any color)
Apply 3-5 coats of a high build 2K Urethane Primer
Guide coat


You normally do not need an epoxy between your filler and 2k primer, but since it is going to be sitting for a while I think it would be a great idea. There are a couple of reasons to spray the 2k primer now instead of later.


You dont have to sand the epoxy (which sands like crap once it is hard) if you get right on it with 2k (within 8 hours).
2k primer needs time to shrink before you block it, and since it looks like your waiting for a while this would be optimum.
2k will hold up just fine (especially with the epoxy under it) for as long as you want to hold off.

[justasquid]

thanks, I was leary about letting the urathane primer stand uncoated. This means I can let it stand for some time as long as the epoxy is underneath. thats great news. I can get the car ready for paint and let it sit.

One more question. If I spray the Urathane primer over the epoxy, and it sits for several months, Do I need to rough that up as well? My plan would be to use something around 400 grit and lay down another layer of primer once its blocked out before I lay down the paint. Does this sound correct? Or will I need to do something else to re-prep the primer before laying on another coat. I want to avoid any sanding marks coming through the paint.

Or, is the new layer primer a waste of time and money as long as the primer has been sanded before paint. And if so, would 600 grit be a better choice?

Im still not sure exactly what paint I will be using. I will more than likely use a 2 stage bc/cc, but I still like the look of the single stages as well. I am painting a solid color, red or black. leaning heavily towards black.

[hotrdblder]

epoxy allows you to apply filler over it, where as urethane primer it is not recomended .the best scenario is to do a panel at a time and body work till perfect, epoxy 1-2 light to medium coats then 1 hr flash then bail on the urethane primer. the urethane primer is actually better for cars that will see moisture, but the epoxy has corrosion resistance

[Paint God]

Once you get around to prepping for paint Block sand dry with 220. If you find that the body is not as straight as you like when you are finished blocking it out in 220 then go ahead and repair those areas. You can skim Evercoat's "Easy Sand" polyester glazing putty right over the urethane primer. Just make sure you finish it out in 220 grit and re-prime the car with 3-4 coats of urethane primer and guide coat. Once this sets for at least a week just repeat the process with 220 dry on a block. You can repeat this over and over until you achieve greatness. Once you are satisfied I recommend wetting the surface with a solvent such as wax and grease remover so you can look it over for waves. Once you are happy go ahead and guide coat over the 220 scratches and then wet sand. If you are going with a solid color I would final sand with 400 wet.

[justasquid]

thanks for all the replys. this helps me out a ton. Ive painted quite a few cars and they have turned out very well. they were all just daily drivers and the paint jobs were just to get some life from the cars, so I didnt put too much time into them. But I learned a lot about what I can do. I've gotten a lot of compliments in the past. But I really want this car to be great. If anything, Im too picky, so I know I will be block sanding for a long time. the good news is Im not in a rush and I can take my time to get everything straight.

again, thanks everyone, I feel much better about this project now knowing the info you guys have provided. it truely is appreciated.