Block sand after which coat of primer?

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PostPosted: Thu May 05, 2011 1:00 pm
My Diamont 2K primer says 2-3 medium coats. great I understand that. I want to add a guide coat and block my primer to check for imperfections before I apply color.

Should I guide coat and block after the first coat? or should I wait until the last coat?


lastly, my tech sheet says 400-600 grit wet sand or 320-400 grit drysand. I imagine Im going to be block sanding dry? Will I need a final coat of primer after I block sand and does that final coat of primer need to be sanded in any way before color?

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PostPosted: Thu May 05, 2011 2:24 pm
Spray your 3 coats,guide coat it and then block it down



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PostPosted: Thu May 05, 2011 2:31 pm
cool thanks ;-)

If i find spots which require filler, would I repair the spot then add just one final coat on top of the filled area? ( or would I have to respray that whole panel again with primer?

reason I ask is because I think i know of one dent I may have missed somewhere but now that its all sanded down I cant find it.



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PostPosted: Thu May 05, 2011 7:44 pm
after you block it then repair any spots that need repair. then mix a small amount of primer and just spot prim the repair areas, and reblock untill their good. i like to put 3 coats of 2k on then block with 180 dry, it cuts much flatter. then quickly go over that with some 220, then 2 more coats of 2k. now guide coat and use your finner grits to block with :)
they say my name is Jay

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PostPosted: Thu May 05, 2011 9:28 pm
Tim1137 wrote:My Diamont 2K primer says 2-3 medium coats. great I understand that. I want to add a guide coat and block my primer to check for imperfections before I apply color.

Should I guide coat and block after the first coat? or should I wait until the last coat?


lastly, my tech sheet says 400-600 grit wet sand or 320-400 grit drysand. I imagine Im going to be block sanding dry? Will I need a final coat of primer after I block sand and does that final coat of primer need to be sanded in any way before color?


You can guide coat it before you put any primer on it to do your filler work first if you like. Or you can put one coat of primer on, guide coat then do filler work.
If its bare metal go first coat etch or epoxy then urethane.
There is more than one way to skin this cat.
Never argue with an idiot, he will drag you down to his level and beat you with experience.

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PostPosted: Thu May 05, 2011 10:19 pm
timbo wrote:
Tim1137 wrote:My Diamont 2K primer says 2-3 medium coats. great I understand that. I want to add a guide coat and block my primer to check for imperfections before I apply color.

Should I guide coat and block after the first coat? or should I wait until the last coat?


lastly, my tech sheet says 400-600 grit wet sand or 320-400 grit drysand. I imagine Im going to be block sanding dry? Will I need a final coat of primer after I block sand and does that final coat of primer need to be sanded in any way before color?


You can guide coat it before you put any primer on it to do your filler work first if you like. Or you can put one coat of primer on, guide coat then do filler work.
If its bare metal go first coat etch or epoxy then urethane.
There is more than one way to skin this cat.

This technique makes for a thinner layer of primer dust on the floor.... :happy:
"If you can't move it, paint it." - U.S. Army

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PostPosted: Fri May 06, 2011 6:49 am
Tim,,,do this.
If you are doing an all over paint job, Check the car very good and do your body work before you apply any primer. Final sand your bondo with 80-180, sand the rest of the car with 220.
I would spray two coats of primer over the bondo, and then spray two more coats over the entire car and also the bondo areas. THEN do your blocking. If you sand through,,no big deal, just spray two more coats of primer.
You never block just one coat of primer.......
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PostPosted: Fri May 06, 2011 8:57 am
ODG is right. If you don't put at least 2 coats of primer down, you run the risk of sanding through too easily.
Then you end up chasing your tail putting more primer down.

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PostPosted: Sat May 07, 2011 12:30 am
do the metal work right the first time then waa laa!
ODG is always right..especially about FLG3 guns......LOL!!
Never argue with an idiot, he will drag you down to his level and beat you with experience.



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PostPosted: Sat May 07, 2011 7:36 am
Since I used a guide coat with the Slick Sand, do I need to use a guide coat again when sanding the 2k primer?
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