Problems with applying clearcoat on enamel

[DarkenReaper57]

I'm in the process of painting some metal panels to a mirror finish. I have mostly followed this guide http://case-mods.linear1.org/case-mod-101-how-to-paint-your-computer-case-part-2/2/

I have been able to achieve a mirror finish without applying the clearcoat, but have run into problems after applying. Basically, it seems like the clearcoat forms strange designs instead of drying uniformily to the paint.

I am using high performance rustoleum black glossy paint and Krylon Acrylic "Crystal Clear" clearcoat.

Oh, I have been using a polish before applying the clearcoat mostly (to get a nice black finish before). I be sure to wipe the excess off completely. I doubt this is the problem, though, since I have tried applying the clearcoat directly after sanding the surface down to 1500/2000 grit and cleaning. The surface is dry, too, I am sure of that.

Could it be some sort of compatability problem between paints? Should I buy the rustoleum clearcoat instead?

What do you guys do to protect your hard work and mirror finish painted surfaces?

Sorry about all the questions, it has just been a rather frustrating day. Thanks for any help.

 

[MikeDeuce]

IIRC, acrylic is ok on top of enamels and lacquers, as it is "cooler" than the other solvents, but not the other way around. My preference is to buy matching brand and series color coat and clear coat to avoid potential compatability issues.

Check this page out and compare your issues to the pictures (particularly the "LIFTING" and "WRINKLING" pics):
http://www.briansmodelcars.com/tutorials/tutorial.asp?TutorialID=30&CurPage=1

Might help narrow it down some.

Also, what are you using as a polish? I use a 3M rubbing compound that is advertised as "paintable" but I still wouldn't use it in between coats. I think rattle cans need all the help they can get.

HTH
mike

 

[SarverSystems]

Correct me if I'm rong, but the way I am reading your question is that you want a mirror finish, and you are accomplishing that by buffing the painted surface. Isn't that giving you the mirror surface already? Clearcoat itself will not give you a mirror surface. Clearcoat is simply spraypaint without the pigment.

If you are getting a mirror surface before applying clearcoat, then the answer is to not apply clearcoat at all.

Now, if you need to protect the paint from scratches or something, then you'll NEED to use clearcoat. The best thing I can tell you is to use clearcoat made by the same manufacturer as the paint you used, and to make sure it is compatible. Acrylic clearcoat won't work on enamel, and won't work on Krylon Fusion. Acrylic clearcoat for acrylic paint, Enamel clearcoat for enamel, etc....

 

[Stu55]

Right you should use the same company all the way through, and keep laquers with laquers and enamels with enamels.

 

[BellaCroix]

You're looking at one of several problems:

Incompatibility between the paint and clearcoat.
Incompatibility between the clearcoat and polish.
Incorrect temperature.
Applying clearcoat too soon after painting.
Incompatibility between the clearcoat and "body soil" (fingerprints, skin oils, etc).
Clearcoat over some types of high-gloss paint.

I used to get that a lot when I used different kinds of paint when painting models. The key is to use a flat color coat (or a regular gloss automotive paint although I've had much better luck starting with flat paint), sand it completely smooth (don't worry about mirror finish, polish, blah blah blah. Then, after allowing the final coat of paint to set for about 2 days, paint the first coat of clearcoat. Allow that to set for about 2 days before wet sanding with 1500 grit. RE-clearcoat over that, allow to dry for 2 days or so. Wet sand that layer with 2000 grit. Re-clearcoat again and, again, allow to dry for 2 days. If you've done everything exactly right NOW it's time to use polish cream.

Unless you are washing the painted surface that you've polished with alchahol you're not getting off all the polish before clearcoating. Trust me, you're not. Do not use that stuff until the very end of the process. Don't worry about a few minor imperfections in your color layer. That's what the clear coat is there for.

I tried using polish, then was "sure" I removed it all before applying another layer of clearcoat. I got MOST of the polish off. But the areas I missed cracked like "crackle" spray paint while the rest of it stayed smooth. Ruined a $175 case that way.

 

[DarkenReaper57]

Correct me if I'm rong, but the way I am reading your question is that you want a mirror finish, and you are accomplishing that by buffing the painted surface. Isn't that giving you the mirror surface already? Clearcoat itself will not give you a mirror surface. Clearcoat is simply spraypaint without the pigment.

If you are getting a mirror surface before applying clearcoat, then the answer is to not apply clearcoat at all.

Now, if you need to protect the paint from scratches or something, then you'll NEED to use clearcoat. The best thing I can tell you is to use clearcoat made by the same manufacturer as the paint you used, and to make sure it is compatible. Acrylic clearcoat won't work on enamel, and won't work on Krylon Fusion. Acrylic clearcoat for acrylic paint, Enamel clearcoat for enamel, etc....

Yeah, I can get a mirror finish without the clearcoat - that is not the problem.

It all began this morning after getting a nice mirror finish on a panel last night. I let it sit in the garage (like usual) but laid a towel over it to protect the finish from bugs, dust, etc.

This morning I lifted up the towel and there were divet marks all over from it. I was pissed. I DID let the paint dry 2 days before sanding, but perhaps that is not enough since I live in Florida where the humidity is high. It could also be that the paint will be soft and easily scratched/deformed no matter what.

I want to protect the finish somehow. That is my entire purpose of applying a clearcoat. If there is an easier way to protect it (wax after a month or two?) please let me know.

 

[DarkenReaper57]

You're looking at one of several problems:

Incompatibility between the paint and clearcoat.
Incompatibility between the clearcoat and polish.
Incorrect temperature.
Applying clearcoat too soon after painting.
Incompatibility between the clearcoat and "body soil" (fingerprints, skin oils, etc).
Clearcoat over some types of high-gloss paint.

I used to get that a lot when I used different kinds of paint when painting models. The key is to use a flat color coat (or a regular gloss automotive paint although I've had much better luck starting with flat paint), sand it completely smooth (don't worry about mirror finish, polish, blah blah blah. Then, after allowing the final coat of paint to set for about 2 days, paint the first coat of clearcoat. Allow that to set for about 2 days before wet sanding with 1500 grit. RE-clearcoat over that, allow to dry for 2 days or so. Wet sand that layer with 2000 grit. Re-clearcoat again and, again, allow to dry for 2 days. If you've done everything exactly right NOW it's time to use polish cream.

Unless you are washing the painted surface that you've polished with alchahol you're not getting off all the polish before clearcoating. Trust me, you're not. Do not use that stuff until the very end of the process. Don't worry about a few minor imperfections in your color layer. That's what the clear coat is there for.

I tried using polish, then was "sure" I removed it all before applying another layer of clearcoat. I got MOST of the polish off. But the areas I missed cracked like "crackle" spray paint while the rest of it stayed smooth. Ruined a $175 case that way.

2 days? Is a day sufficient for the fast-drying clearcoat stuff made by krylon?

After all of the coats of clearcoat and high grit sanding, is a mirror-like finish still possible? Is the finish at least uniform and not speckled?

 

[Ski Me]

This is the way I learned to paint for a high gloss finish. After cleaning and priming apply at least 3 coats of your base color allow 1 day to dry between coats and wet sand with 400 to 600 grit then apply your clear coat the same amount as your base color same drying time and wet sand first with 400 to 600 grit for the first coat then 1200 grit for the last two coats. Your finish should just looked dulled but not scratched. Let the panel sit for about a day after your last sanding then use a polishing compound to get it to that first stage of shine then finish off with a glaze. I use 3M and get great results.