Poly clearcoat over spray-can paint...?

[delt]

Hey all, i've been looking all over this thread see if it's a good idea to use a polyurethane clear coat over enamel / acrylic / lacquer spray paint and how well that would work.

... anyone? thx

[Bengal65]

A 2 part automotive Polyurethane like PPG or Dupont brands will work over those finishes. Clean the guitar with Naptha scuff the surface with 400 grit wet dry sandpaper, wipe down and go.

[delt]

Thaks for the reply =) "wet dry" you mean wet sand, then dry sand, right?

Also, how much curing time should i allow the spraycan paint before putting the 2-part poly?

[sully]

no. wet/dry sandpaper = can be used either wet or dry.

[Newc]

Rattle paint dries very slowly. I sprayed a guitar 2 years ago and it took about 6-8 months to stop feeling tacky, and that was just the color coats.

I have not been able to finish it due to the weather since then (we never had a Spring last year - we went from cold rainy Winter straight into hot muggy Summer - the local cotton and soybean farmers were pleased )

Anyhoo, I know it gets big laughs, but that guy that sells the How To Paint Your Own Guitar With Just A Couple Of Spray Cans book on Ebay has been doing it for 20 years, and he's got some great info.

http://www.paintyourownguitar.com/

[ihocky2]

It will work most of the time, but I would try and test it on some scrap first. I have seen it depend more on brands used than types. PPG might stick mine to Deft, or Behlen, or Krylon, and then refuse to stick to Duplicolor.

[rjohnstone]

This is a rattle can job (Krylon enamel) with an automotive clear coat.

Just make sure you prep it properly and let the rattle can job dry completely before you spray the clear.

[delt]

^ whoa, nice finish there man! Did you mask the logo?

Let the rattle can paint dry completely, that should take at least 2 weeks, right?

Again, thanks to everyone for the tips =)

[rjohnstone]

^ whoa, nice finish there man! Did you mask the logo?

Let the rattle can paint dry completely, that should take at least 2 weeks, right?

Again, thanks to everyone for the tips =)

Nope... just a decal. Buried it under a couple of layers of clear. You can still feel it though.

As for drying time... depends on how many coats you did, how thick you applied them (thinner is better) and how long you let it setup between coats.
The neck sat for a month before I cleared it.
The body was cleared at the same time and it turned to shit fast.
It has been repainted and has been hanging in my father-in-laws garage for the last 6 months "curing". It's almost ready for the hard clear coat.

[mm2002]

Yep, just like Rick did, wait at least a month. If you use spray lacquer, and put it on very lightly, you can get away with a week or two.

[sully]

good rule of thumb with lacquer is to wait until it doesn't smell like paint.

[Bengal65]

good rule of thumb with lacquer is to wait until it doesn't smell like paint.

+1 Good one. I forgot to add awhile back and has been pointed out is to wait for the lacquer, acrylic enamel etc. to really cure good before you fo the PolyU. Years back when automotive lacquers where being phased out for industrial automotive refinishing, the clear urethanes came out first before the colors. That was probably 1982 or 1983. (Remember those days Mark?) I did many guitars with the lacquer, then used the clear Polyurethane for topcoating.