Wetsanding basecoat

[777daystar]

I sprayed my black basecoat and noticed some lint and alittle dust on my project when dry. Instead of going ahead and spraying the clearcoat I lightly wetsanded all the black to get out the lint. The question is, do I have to shoot the Black again before I can clearcoat, since all the wetsanding did was haze it a little?

 

[TAZ]

If you used a fine wet sandpaper (1500 and smoother), you will be allright.

Make sure the lint or dust was not a different color other black?! If it is or you can see the specs, just dust some black base back over it.

Don't let the base sit too long before clearing. The approx. window before you would have problems with the clear sticking to the base is about 24 hours max.

In fact, why not clear it now

 

[ezrider]

When nibbing dust in base coat try using a little final wash (depending on the brand you are using) on the sand paper insted of water. it cleans up and dries a little faster than water.

 

[rex]

I like to dust another coat over it personally,but you don't have to.It's funny that a dirtnib in black turns to a white spec,but in white it's a black spec.If you went past the recoat window you'll have to put on another coat of base before clearing.

 

[rex]

Sorry.That's the 24 hour thing you hear about.Every paint has a window of open time you use to recoat it.Most basecoats are 24 hours (like PPG),but check to be sure.After that time is up you sand and put another coat of base on and go on to clear as normal.Now,when you get to the clear or other topcoats,you have to really pay attention.If you wait too long between coats the first will wrinkle like crazy and it's no fun at all.Don't worry though,just read all the directions on the cans for the paint system you're using.They'll tell you the flash time between coats and the maximum time for recoat.It's likely there are no directions on the label so go down to the paint store and ask for a copy of the P-bulletin for the base and the clear you're using.

 

[Krishna]

There's a recoat window?

 

[FastCat]

Hmm, interesting information, so much to read, so little time between coats. I am in the process of restoring some parts for an '85 GS700ES. Mainly tank and a fairings. So far I've managed to strip or mostly strip, factory finish was cleaned up with wetsanding, but left on some of the plastic parts.

This weekend I primed a couple plastic pieces, I just got finished wetsnading the dry primer with 2000 grit wetsanding paper to smooth out any imperfections in the first primer coat.

My questions:

I was going to give it another coat of primer tomorrow evening, and then wetsand it again once dry...then apply basecoat next weekend.

Does the 24hr rule apply to primer also?

Will it be ok to prime this weekend and basecoat it the next?

Basically it boils down to at least 2 days between primer coats, and one week between 2nd primer coat and first basecoat.

Is this ok?

Once the first basecoat goes on, does the second coat of base have to be on within that 24hr period and clear on top of that?

Can I base coat one and wetsand one weekend, then recoat and clear on the next?

Do I need to wetsand the second coat of basecoat prior to clearcoating?

I'm abit confused on how many times I have to wetsand and in between which coats and how many coats for each type of paint.

Is it ok to wetsand mettalic basecoats? Like a mettalic gunmetal color, will wetsanding ruin the finish? do I need to wetsand between clearcoats? do the two coats of clear fall under this 24hr rule also?

From what I can surmise so far, 2 coats of base and 2 coats of clear have to go on in quick succession.
Not to mention the primer coats.

What I want is a good glossy finish, I planned on two coats of each, primer, base and clear. What should be my wetsanding schedule and paint schedule.

Newbie in need

Please help.

TIA.

 

[kevsLX]

FastCat, 2000 is too fine for sanding your primer. What primer are you using?
Generally with metallic colrs, you would do your final sand on primer with 600, and usually 400 is OK for solid color basecoats. You should resand that primer with 400 wet, or 320 dry and recoat. Then sand again before shooting your base.
As long as you're shooting over sanded primer you really don't have to worry about a recoat window as long as the primer has not been exposed to the elements for too long.

On your basecoats, yes they do need to be cleared or recoated in 24hrs, but if you sand the base then you have more time before you have to recoat because you have opened up the pores and given the next coat something to bite into.
I usually do not wetsand base coat unless something horrid found its way into it while it was wet.

Check the tech sheets on your clear. PPG 2021 can go 7 days before you have to sand if you're going to shoot a couple more coats. Well, that's what the tech sheet says anyway, but I like to clear, let it sit a day then wetsand with 800 and clear again.

 

[rex]

Kevin summed it up well.What you want to do is prime it with 2 or 3 coats of primer and let it dry for the required timeframe.If you're not filling bodywork or taking out a bunch of featheredges finish sand it,seal it and paint it.When you base it go to color coverage.A few dust nibs will dissapear but chunks of dirt that are apparent will be better off nipped out with sandeing and recovered with a quick coat of base.The 24 hr thing is more something has to be put over it like more base or clear than between coats.Generally each coat of base will take 15min between coats until coverage then in 15-30min clear can go on with 5-15min flash times.If you have to nip a metallic base you have to put another coat over it to hide the 'burn' spot that happens sanding metallics and pearls.

 

[huck]

i'm new to this painting. just wondering about this 24 hour window to get the clear on???? How to these guys that do the intricate airbrush ARTwork on bike tanks get the time to do what they do in such a short time.
Hence, my own question. Ive bought a new set of 7 gal. tanks for my '90 Heritage that Ive pressured tested, sealed and etch primed. I'm going to have them base coated black and was then, over the next month or so, when time allowed, I was going to try my hand at a flame job and then have the clear laid on. If the recoat window is a fact what are my options?? Can I have the base given one coat and do the flames on that.
I'm getting an information overload on all this info I'm trying to absorb before I attempt my project. Will greatly appreciate any help.

Regards,
Huck

 

[rex]

Welcome Huck.Man those are big tanks once they're mounted,you did prefit them for clearance on the trees and bars right?First thing you'll have to do is rough up the etch primer and either reaply it or get a primer on it,it has a window of 24hrs(surprise!) or so too.You have a few options to paint it.You can base it and intercoat clear it,then scuff it and continue on later doing the intercoat and scuff between sittings until final clearing.The prob with this is you're piling up base pretty thick.I prefer tp clear the base and set it aside till later.Then sand it and continue.Once I hit 5 or 6 coats of base (color and clear) it's getting nerve racking and I want some topcoat clear to lock it down.Putting another 5 or 6 on it aren't good either so you want to do a lockdown more often.You're better off with a few coats of base between a few clearings than a pile of base between 1 or 2 clearings.