Runs in the Primer

[AY2043]

Hi everyone,
I'm in the process of painting my first build, and I sprayed the primer a bit thick on the first go around, resulting in some runs. Should I go ahead with the next coat of primer, or sand the runs out before continuing?
Thanks in advance,
Adam

[sacrificetravis]

What kind of primer is it. I'd say wet sand it... but idk how that would work on wood... never painted a guitar before.

[Colt W. Knight]

I would dry sand those runs out with some quality 400 grit sanding paper and a sanding block. Wipe it down/blow it off, and respray another coat of primer. Its important to get the primer smooth and defect free before proceeding to color.

[dsutton24]

Once you start sanding you may find that the sags are holding a lot of wet or gummy paint. Best to deal with it now rather than hours, paint, and dollars later.

[AY2043]

Thanks for the responses guys. I'll hit it with 400 dry tonight and spray another coat tomorrow. Hopefully it comes out nice and even. Does anyone have any tips on what to look for in the final coat of primer before its safe to move on to the color coats?

[e-merlin]

Gawd, I hate the runs...

[Colt W. Knight]

Originally Posted by AY2043

Thanks for the responses guys. I'll hit it with 400 dry tonight and spray another coat tomorrow. Hopefully i t comes out nice and even. Does anyone have any tips on what to look for in the final coat of primer before its safe to move on to the color coats?

Smooth , even color, and no scratches or wavy spots.

[R. Stratenstein]

If you're shooting nitro primer, and the same holds for lacquer, too, sometimes it's amazing how the finish will flow out from a run. I've had some that put me in a near panic while wet, but after letting it dry thoroughly, there's almost nothing there, or what's there is easily sanded. Just sayin, don't get in a tizzy and start mucking around while its still wet or tacky, some of it may resolve itself.

[flyingbanana]

Originally Posted by R. Stratenstein

If you're shooting nitro primer, and the same holds for lacquer, too, sometimes it's amazing how the finish will flow out from a run. I've had some that put me in a near panic while wet, but after letting it dry thoroughly, there's almost nothing there, or what's there is easily sanded. Just sayin, don't get in a tizzy and start mucking around while its still wet or tacky, some of it may resolve itself.

+1. Nitro can be pretty forgiving sometimes.

[Shepherd]

Originally Posted by AY2043

Thanks for the responses guys. I'll hit it with 400 dry tonight and spray another coat tomorrow. Hopefully it comes out nice and even. Does anyone have any tips on what to look for in the final coat of primer before its safe to move on to the color coats?

The final coat of primer has to be perfect otherwise any defects will be magnified in the color coat.

[Keyser Soze]

Originally Posted by Shepherd

The final coat of primer has to be perfect otherwise any defects will be magnified in the color coat.

I agree.

Primer sands much easier than anything that will follow. There is no reason not to correct the defect prior to proceeding.

Block sand the high spots down with 400, and lightly scuff sand the entire surface, then continue with the final coat(s) of primer.

Depending on the pigment(s) used it is not just a concern for physical defects in the primer surface, differences in sheen (from sanding or even contact pressure) can prove visible through the paint.

Perfect prep makes everything that follows much easier.

[AY2043]

Ok so I sanded it and shot another coat of primer (nitro from reranch btw), and it looks/feels pretty darn good and smooth. I'll let it dry over night and lightly touch it up with some more 400 tomorrow. After that I'll wait til my can of sea foam green paint shows up! Thanks for all the help, and I'll be sure to ask if I have any more questions if/when I have any.

--Adam

[Silverface]

If you are using lacquer undercoater/primer/sealer (all those names are used on labels) once you get it sanded nice and smooth there is ONE thing to be very cautions of when applying color coats - and that's applying the initial color coats too thick. They can re-wet the primer underneath and runs may have primer streaks in them...which can progressively leach through additional coats. Go lightly with the color at first.