The window with which to apply topcoat or, in my case, seam sealer to the epoxy primer is about 7 days. Inside of that window, there is no need to sand the surface prior to applying a product on top of it such as more paint, body filler, etc. Since it had only been a few days since I had sprayed the epoxy, I was well within my time.
I didn't take a whole lot of pictures for this process, but I did the same as I had done for underneath. I used the AC Delco caulk tube seam sealer in the deep seams between panels and the Evercoat brushable seam sealer over top of that and wherever two panels overlapped each other.
|Under the dash on driver's side (car is up on the wings).|
|Around the battery box. Again, car is up on the wings.|
With that done, I flipped the car fully over and started scuffing up the underneath. Since it's been the better part of two months since I sprayed epoxy in this area, I needed to scuff it up for proper adhesion of a topcoat. Once outside the 7-day window, the epoxy needs to be hit with 180-grit sandpaper prior to applying paint, body filler, etc.
|Flipped and ready for prepping.|
I went over everything with 180-grit sandpaper and then used the maroon pads and the paint stripping pads to get the hard to reach areas. Since the epoxy dries with a pretty good shine to it, my goal was to get all of the areas dulled up as I figured this would be a good way to tell if I got it all. There's still some cleaning to do, but the scuffing should be done.
|All scuffed up and ready for the sealer coat of epoxy.|
Once that's done, I will shoot a sealing coat of epoxy. This is regular epoxy but "cut" about 25% with urethane reducer. This will provide a good transition between the base epoxy and the Raptor Liner and is what SPI recommends when topcoating their epoxy outside of the 7-day window. I'll give the epoxy about 2 hours to dry and then shoot the Raptor Liner.
I'm modifying a cheap purple gun from Harbor Freight (drilling out the tip to about 2mm since they don't sell different size tips) and using that for laying down the Raptor Liner as I want a smoother finish than the gun that came with the kit would provide. At least, that's the idea. You'll have to wait until next time to see how it went!