Blocking with 220, sand-throughs, glazing questions.
I've been sanding (wet, block) my epoxy with 220 to get ready for 2k primer/surfacer and have cut through in a few small spots. There are a few places, also small, where I missed some high spots and the epoxy is nearly transparent by the time it's flat.
Should I just spray some more epoxy on each of these before going on to the 2k primer/surfacer or do I need to shoot a complete coat of epoxy? If I shoot a complete coat, will the 220 be a factor, versus the 80 that seems to be the norm for prepping for epoxy?
Background and tales of screw-ups:
This is my first attempt at basecoat/clearcoat. It actually started over 2 years ago, but things got in the way. The car says 'Fox' on the label, but it's really a lab rat -- I'm using my wife's car to learn how to do bc/cc for my real project. She set a low threshold ("As long as it shines") but I want to learn to do it right.
The epoxy is EPX-900/901, from some advice given to me by baddbob 'way back when I was trying to get the hood protected. data sheet (PDF) That data sheet shows beige, gray, black and white, but this stuff is close to Caterpillar yellow.
I shot 2 coats on mostly bare metal and then sanded most of those back off because (a) it was a mess and (b) it was far beyond any reasonable stretch of the recoat time.
After getting 2 decent wet coats on and waiting a day, I blocked with 80 and did filler work with Evercoat Lite-Weight. That was cut down with 40 and then 80. Well, that was the intention. Work was interrupted, I was in a hurry when I got a chance to get back to it and I ended up spraying a coat over some filler that had only been hit with 40 grit. It was hideous.
I'd already mixed enough for 2 coats, so I shot 'em and then sanded the whole thing back down flat. My whole garage floor turned yellow. The only good thing about the waste was that blocking it again showed a low spot I had missed before. It was right beside a high spot on the roof that's half way around a dimple. All together the area looks like a quick-frozen ripple in a pond -- dimple, wave crest, wave trough. After blocking that, it looked like a light blue smudge beside a yellow one next to bare steel.
Now I have 2 good coats over the filler, not counting the bugs. The tech sheet (PDF) for JP202 primer/surfacer says prep with 180 - 240 grit, so I started blocking with 220. I've cut some edges all the way to the metal and sanded really thin near some others.
My intention was to spray the JP202 at 4:1:1 (recommended by Janet at "The Bodyman's Friend" where I bought all the supplies) to get a better color under the base and to act as a sealer over some Icing that I'll need to fill where the bugs died. That local PPG supplier doesn't even stock the JP385 2k sealer, so I'm guessing none of the local body shops use it.
I was told that not using a sealer over the Icing and primer/surfacer will cause areas coated with Icing to be visible through the basecoat. Does that sound reasonable?
I've also been told that the color I've chosen, a VW "Tornado Red", will show every flaw I leave behind. Oh, well, it's a learning experience. Besides, another screw-up on my part regarding a list sent by way of a volunteer go-fer resulted in me being the proud owner of 6 quarts of Tornado Red. (I was able to return the extra gallon of clearcoat and hardener). The Fox/lab rat/guinea pig is about the size of a Pinto. Might have to paint a few more vehicles around here a bright red.
data for the basecoat (PDF)
data for the clearcoat (PDF)
I've been sanding (wet, block) my epoxy with 220 to get ready for 2k primer/surfacer and have cut through in a few small spots. There are a few places, also small, where I missed some high spots and the epoxy is nearly transparent by the time it's flat.
Should I just spray some more epoxy on each of these before going on to the 2k primer/surfacer or do I need to shoot a complete coat of epoxy? If I shoot a complete coat, will the 220 be a factor, versus the 80 that seems to be the norm for prepping for epoxy?
Background and tales of screw-ups:
This is my first attempt at basecoat/clearcoat. It actually started over 2 years ago, but things got in the way. The car says 'Fox' on the label, but it's really a lab rat -- I'm using my wife's car to learn how to do bc/cc for my real project. She set a low threshold ("As long as it shines") but I want to learn to do it right.
The epoxy is EPX-900/901, from some advice given to me by baddbob 'way back when I was trying to get the hood protected. data sheet (PDF) That data sheet shows beige, gray, black and white, but this stuff is close to Caterpillar yellow.
I shot 2 coats on mostly bare metal and then sanded most of those back off because (a) it was a mess and (b) it was far beyond any reasonable stretch of the recoat time.
After getting 2 decent wet coats on and waiting a day, I blocked with 80 and did filler work with Evercoat Lite-Weight. That was cut down with 40 and then 80. Well, that was the intention. Work was interrupted, I was in a hurry when I got a chance to get back to it and I ended up spraying a coat over some filler that had only been hit with 40 grit. It was hideous.
I'd already mixed enough for 2 coats, so I shot 'em and then sanded the whole thing back down flat. My whole garage floor turned yellow. The only good thing about the waste was that blocking it again showed a low spot I had missed before. It was right beside a high spot on the roof that's half way around a dimple. All together the area looks like a quick-frozen ripple in a pond -- dimple, wave crest, wave trough. After blocking that, it looked like a light blue smudge beside a yellow one next to bare steel.
Now I have 2 good coats over the filler, not counting the bugs. The tech sheet (PDF) for JP202 primer/surfacer says prep with 180 - 240 grit, so I started blocking with 220. I've cut some edges all the way to the metal and sanded really thin near some others.
My intention was to spray the JP202 at 4:1:1 (recommended by Janet at "The Bodyman's Friend" where I bought all the supplies) to get a better color under the base and to act as a sealer over some Icing that I'll need to fill where the bugs died. That local PPG supplier doesn't even stock the JP385 2k sealer, so I'm guessing none of the local body shops use it.
I was told that not using a sealer over the Icing and primer/surfacer will cause areas coated with Icing to be visible through the basecoat. Does that sound reasonable?
I've also been told that the color I've chosen, a VW "Tornado Red", will show every flaw I leave behind. Oh, well, it's a learning experience. Besides, another screw-up on my part regarding a list sent by way of a volunteer go-fer resulted in me being the proud owner of 6 quarts of Tornado Red. (I was able to return the extra gallon of clearcoat and hardener). The Fox/lab rat/guinea pig is about the size of a Pinto. Might have to paint a few more vehicles around here a bright red.
data for the basecoat (PDF)
data for the clearcoat (PDF)