Which sealer to use/Basing over top of sanded 1:1 epoxy?

S

SmokeyHaze

I'm helping my grandfather out, and painting his 73 vette for him. The car started out silver and had 1 respray to black I'd say sometime in the 90's. The corvette was pretty straight already and paint had no issues other than one spot which over time had settled into a little body filler and ringed. For the most part it was just stone chips and very minor waves in the body. Everything going on the car is from SPI except the base. I am using the epoxy, standard 2K primer, UV clear with slow hardener. I also bought SPI slow reducer I was planning to use in the PPG solvent base. The color is going to be Tuxedo Black from Ford, paint code UH.

I started out by just stripping most of the paint off the car with 120 grit on a DA. Everything sanded really nice. Let the car sit a couple days, and sprayed 2 coats of epoxy. Waited about a week, then hand blocked with 180 and sprayed on 2 more coats of epoxy. Let the car sit for about 7-8 days and block sanded with 240 and sprayed 2 coats of the standard SPI 2k primer. I have yet to do anything with the car since, and will be blocking off most of the 2k to get the car straight. If its where I'd like it to be, I will be getting the car ready for the booth some weekend soon.

Now that you have most of the information on my overall, my question is what sealer do you guys recommend? At work I seal everything with a solvent based sealer from PPG used for waterborne. At first I was planning to use a Deltron PPG sealer for solvent, then changed to using reduced epoxy from SPI because I already had everything needed and it would be a good black base, to base over. After reading almost every post on here it seems like most people use the reduced epoxy mostly as a adhesion promoter. Id like to have something solid to lock everything underneath of it down and have good hold out for everything over top.

Could I block sand this 2k and do another 1-2 coats of black epoxy, final block with 600 and base? In theory to me, it would be a stronger version of the reduced epoxy sealer. I read a thread from 2011 on here in which someone said still seal overtop. I know its different but the PPG epoxy I spray at work can be based right over top. Wasn't sure if this epoxy could be also. Thanks for taking the time to read all this and hope I get some good responses!

-Derek
 
Just spray one or two coats of unreduced epoxy. Some people reduce it to get it to flow out, but I find it so easy to put the unreduced epoxy on smooth as butter to start with, there's no need. Then wet sand with 600 to remove dust nibs and any peel. Then go to base. Or you can go straight to base without sanding if it's perfect.
 
I reduce epoxy about 10% then if its perfect lay base a few hours later, if not I interface with 400 for solid colors and spray right after I get the sanding cleaned up.
 
I have used the gray and the white epoxy for sealing and I also reduce 10%. I sand to 320 and then spray the reduced epoxy with my base gun and then go directly to paint after waiting at least an hour
 
SmokeyHaze;39982 said:
I know its different but the PPG epoxy I spray at work can be based right over top. Wasn't sure if this epoxy could be also.

You can base right over top of SPI epoxy also but the as the time between shooting the epoxy to the time base is applied so does the adhesion decrease-if that makes sense...

Regardless if you use epoxy for your last round of primer or not for best results your always better off shooting a thin coat of epoxy on before your base is applied, your application thickness and temps will determine how soon you can apply the base. If it's a really thin coat you can shoot your base after the epoxy flashes off. Shoot the sealer, shoot a coat or two of base and if there's any denibbing needed just let it set a couple of hours and denib then shoot the rest of your base and let it set overnight. Lightly tack if off the next day and shoot your clear. If you have a lot of denibbing sanding can be a pita on fresh basecoat but if you use a fine grit like 1000-1500 and solvent wax and grease remover or mineral spirits instead of water it goes well.

PPG's DPLF is a completely different animal, I've washed that stuff off with thinner after it was two years old-you won't see that happen with SPI
 
I agree with what Bob says and would add that if you haven't done any bondo work after the last coat of epxoy and just used 2K to block things then you would have nothing to worry about. At this point with epoxy then 2K to just keep things straight (like using it for a guide coat) you will have no problem with just going to paint if you wanted to.
 
Bob. Could you tell me more about sanding with mineral spirits or solvent w/g remover? What are the benefits?

Never heard of this.
 
I actually spray PPG DPLV in here at work. I've also heard really bad things about the older DPLF and how it turned some of the body guys off of using an epoxy. I've had really good results with the LV though in here.

I've also heard good things about the SPI as to why I've changed to them for everything I do outside of work. So far great results with it as well. I will say the induction time is the only thing I could do without, if I run short I have to wait another 30 minutes, but it's nothing much to complain about.

I really appreciate all the responses though, I'm taking a lot in. Not being as familiar with these products as I am with the PPG it's nice to hear what everyone's look is towards them.

I'm going to block sand the 2k tonight and if it's sands out to where I'd like it I'll go with the 10% reduced epoxy as a sealer. If I need another coat I might do another 2 coats of the epoxy and more hand block and then be ready for reduced epoxy sealer and paint. I like finishing primer out to 600 for Metallica/pearl solvent, and 800 for water. What do you guys recommend finishing out the last coat in before the 10% reduced epoxy sealer. Thanks

-Derek
 
I would finish sand with nothing coarser then 400gt before applying sealer, 600gt if going straight to paint. If you wetsand it the next day or day after it will sand easier then letting it sit a week or longer. Again if you block the 2k and like the result you would be fine to go straight to paint, if you deside to do another 2coats Epoxy and sand again you will have no need to do a seal coat before paint unless you really want to and haven't cut thru to the 2K.
 
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