what sand paper to use?
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TECH Regular
Joined: Aug 2005
Posts: 452
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From: Fort Worth,TX
what sand paper to use? I'm soon going to paint my car i have a sunoco hood i was wondering what sand paper did yall use to get it ready? i was thinking 400, is that to rought or will 600 and up be better?
Depends on what's going down on your hood.
I went over my VFN hood very carefully, poking at each little bubble or crater (there were a few). I did break through in a few very thin spots. These got repaired with some tiger hair and then some putty (I use Evercoat products).
After I block sanded these putty spots down, I scuffed the whole hood with 320 grit. Then some high build primer, then I block sanded with 180 / 320, then more primer, then more sanding, etc. I finished off my last coat of primer with 320 then 600 grit, using 3M's dry guide coat. My base went on the 600, and it filled in just fine.
It really depends on what you're spraying on the fiberglass. If the hood is perfect, it could just be scuffed down with 400 or 500, a nice layer of epoxy primer, and then start the base/clear after that. If the hood has pinholes or very thin spots (mine had a spot about 1/2" x 2" near the windshield that the top layer of resin was so thin it crumpled away with a very slight push), it needs to be filled and primed properly. Block sanding a high build primer removes any weird ripples you might see due to the filler.
Wash it with Dawn before you start sanding, get it clean.
I went over my VFN hood very carefully, poking at each little bubble or crater (there were a few). I did break through in a few very thin spots. These got repaired with some tiger hair and then some putty (I use Evercoat products).
After I block sanded these putty spots down, I scuffed the whole hood with 320 grit. Then some high build primer, then I block sanded with 180 / 320, then more primer, then more sanding, etc. I finished off my last coat of primer with 320 then 600 grit, using 3M's dry guide coat. My base went on the 600, and it filled in just fine.
It really depends on what you're spraying on the fiberglass. If the hood is perfect, it could just be scuffed down with 400 or 500, a nice layer of epoxy primer, and then start the base/clear after that. If the hood has pinholes or very thin spots (mine had a spot about 1/2" x 2" near the windshield that the top layer of resin was so thin it crumpled away with a very slight push), it needs to be filled and primed properly. Block sanding a high build primer removes any weird ripples you might see due to the filler.
Wash it with Dawn before you start sanding, get it clean.
Good prep work man, all i know is on fiberglass/gel coat, you have to sand down first and prime atleast twice, otherwise the fiberglass wants to come back through the basecoat or clear
All of the above steps are right. I would just add that if you're painting it a solid color then 400 wet as your final sand would be fine. IF it's a metallic color then I would go to 600 wet as your final sand. Metallic will show sanding marks much quicker than solids and require a finer finish grit on the primer.
Bryan
Bryan
BTW, my sandpaper drawer has:
80 grit pressure sensitive adhesive roll
80 grit psa disc
180 grit psa roll
180 grit psa disc
320 grit psa roll
320 grit sheet
500 grit wet/dry sheet
600 grit wet/dry sheet
1500 grit wet/dry sheet
2000 grit wet/dry sheet
All Mirka paper, except the 180 roll which is 3M gold.
I use the 180 roll, 320 roll, 600 wet, and 2000 wet the most. I have the $50 Durablock kit that I use with the psa rolls.
80 grit pressure sensitive adhesive roll
80 grit psa disc
180 grit psa roll
180 grit psa disc
320 grit psa roll
320 grit sheet
500 grit wet/dry sheet
600 grit wet/dry sheet
1500 grit wet/dry sheet
2000 grit wet/dry sheet
All Mirka paper, except the 180 roll which is 3M gold.
I use the 180 roll, 320 roll, 600 wet, and 2000 wet the most. I have the $50 Durablock kit that I use with the psa rolls.
