Paint being stripped while sanding. Help!!

[jmattbassplaya]

My friend is constructing a DIY telecaster guitar.

We both used a white primer for our builds, but while I used white for my main coats he decided to go with black. No biggy... or so we thought

After we began sanding down our last coat of paint, he quickly began to notice that his black finish was coming off and turning a dark gray(perhaps the primer and finish mixed?). The once thick and shiny black is now a murky gray. We aren`t sure what to do since we know we need to sand down the finish some, but even after he put down 3-4 pretty thickly, the primer seems to be showing through.

Any tips on what to do to fix this? Should we add more layers to his coat and start over with an even higher grit(we used 320)?

Thanks

 

[dave120]

Are you sure it's actually primer showing through? Sanding black usually leaves a pretty dark grey looking finish until it's got clear over it, or it's sanded up through 2000 and buffed with rubbing compound and swirl remover.

I remember the first time I painted something black, sanded it, and it looked grey to me, so I kept shooting black, sanding, and eventually realized it looks black again once you start the clear. Did you shoot more black over it and it still looks grey? Because that shouldn't happen. When its wet from the wet sanding, does it turn black again, or is it grey all the time?

 

[Rocky McDougall]

Buff an area and see if the problem is just a sanded finish like Dave120 said. If that is not the problem then you need more paint thickness.

 

[jmattbassplaya]

Hey guys,

From the looks of it I think Dave hit the nail on the head. After looking at the body a second time, it just looks like it needs the finish put on. We talked to his father and he basically said the same as Dave so I think we`re okay. Basically it looks like the gloss from the black paint was dulled down which gave the impression that the color was drastically different when it really wasn`t.

Thanks for the help!

 

[dave120]

The quick way to tell is wet it a little bit, if its black then you're fine. Seeing as you're using white it'd be a lot less obvious, but it probably looks the same

You'll be able to tell if you sand through black over white primer. It will rarely only partially show through and it won't be over the whole thing, you'll get little streaks and dots of pure white. Good luck!