Sanded through blocking 2K

Toolin

Toolin

Promoted Users
Here is my situation. On the right fender the process has been. 2 coats of epoxy, some filler, poly primer and 2K. At this point I feel I have it very straight. The issue is I am through various layers of the aforementioned and to bare metal on one spot 3/16" x 1/2" on the rear edge. The thought of putting on two more coats of 2K and having to block it again it again is not so appealing.

I ask if two coats of unreduced epoxy may be the better route seeing it would be less build and hopefully less likely to sand through. I would follow up sanding with 320 dry then 400 wet before sealer and white single stage.
 
Toolin said:
ask if two coats of unreduced epoxy may be the better route seeing it would be less build and hopefully less likely to sand through. I would follow up sanding with 320 dry then 400 wet before sealer and white single stage.
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Yes Sir that will work. You never want to apply 2K over bare metal anyway.
 
Thanks Chris, The other thought was using regular build 2K and reducing it. The SPI site says you can reduce it up to 25%. I suspect the epoxy will make for a more lasting job.
 
The point is to get the bare metal sealed with epoxy primer.

If you are certain that your panel is straight, why not shoot a reduced coat of epoxy that will lay down like a sealer, then apply your sealer coat (assuming it is a different color than your epoxy) and move to your single stage?
 
Toolin said:
The thought of putting on two more coats of 2K and having to block it again it again is not so appealing.

I'm no way a professional body man, but if you have blocked and exposed all the different layers and some bare metal, you really need to spot in the bare spot with epoxy and reapply a couple more coats of blocking primer or enough epoxy to block without once again exposing all the different layers. very experienced pros can get away doing less. IMO if it is as you described you're not going to be satisfied with the outcome by skipping one more blocking. All those different layers sand differently and your panel could look wavey when you finish it.
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'68 Coronet R/T said:
If you are certain that your panel is straight, why not shoot a reduced coat of epoxy that will lay down like a sealer, then apply your sealer coat (assuming it is a different color than your epoxy) and move to your single stage?
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2 Reasons. One I didn't mention that I am only up to 180 Grit and will need more build to refine that to 400. The other is I'm concerned about the exposed poly primer mapping. I figure the epoxy will fill the 180 scratches.
 
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Toolin said:
I ask if two coats of unreduced epoxy may be the better route seeing it would be less build and hopefully less likely to sand through. I would follow up sanding with 320 dry then 400 wet before sealer and white single stage.
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Not a pro, but that's what I would do. Not even sure the sealer coat is needed after the 2 coats of unreduced epoxy.,
 
Okay... So to recap. I have the panel in 2K blocked to 180 grit straight and flat. Two coats of unreduced epoxy. Block W/400 dry, then wet sand W/400.

After that could I go straight to single stage as Dean Jenkins alluded to or should I do a piss coat of 1:1:1 epoxy prior?
 
Toolin said:
2 Reasons. One I didn't mention that I am only up to 180 Grit and will need more build to refine that to 400. The other is I'm concerned about the exposed poly primer mapping. I figure the epoxy will fill the 180 scratches.
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There’s a better way to do it. If you think you’re all done, first spot spray any bare spots with epoxy, two coats. Leave any extra mixed up because you’ll need it in a day or two.

Next, spray one coat 2k over entire car. This just filled in your 180 scratches. Sand this coat with 400. This completely eliminates the issue you were worried about and you don’t have to worry about not getting 180 scratches canceled out.

Next, if you’re me, it’s one unreduced coat of epoxy over the entire car. Then I wet sand this 600 and you’ve got a perfect surface for base.
 
I have struggled with this and asked Barry his advice. He says if it’s a spot of metal that small and collision job, just spray more 2k. Resto, mix up an ounce of epoxy hit the bare spots and 2k prime whole panel next morning.
 
Please hurry I need a fast answer.

Currently I have the panel in 2K blocked to 220 grit straight and flat. Next, 2 coats of unreduced white epoxy, block W/400 dry, wet sand W/400 and followed up with single stage. The Motocryl single stage color I will be using is a very bright white.

I am just about to mix up the epoxy and I have about a quart of 1 year old activator that is amber in color. I know it's still good because I've been using it. I have read that will make the epoxy a tad bit yellow. I have no idea how sensitive the resulting color match of the white SS will be to a slightly different color of the epoxy. Soon I will be using new activator for the same purpose once the year old is used up. If there's any chance this may affect color match I will use the old stuff for something else.
 
Yep, I use it all the time with no issues whatsoever.
If your color coat is decent quality 3 coats should give full coverage. An extra coat should quiet any fears you have.
 
Don, Interesting you ask. I have been going back and forth on how many coats and whether I go the flow coat route. I just recently decided not to flow coat and do 4, maybe 5 coats. I do plan and getting it flat before I buff and I'm a little less than confident in my top coat application abilities. I do suspect I'll be able to lay it down relatively well. Fingers crossed. That is why I'm starting out with just one panel. Once I get in a groove I will be able to do more per session.
 
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