1-Shot micro bubbles

[CES020]

I primed some sign foam with FSC-88, two coats, sanded after it dried, wiped it all down, put some 1-shot on it with a brush. It looked like glass. I kept walking by it and marveling at how incredibly glass like it looked. Came in this morning, picked it up, it's got 100's of tiny microbubbles that look like they migrated to the surface at some point doing the drying process.

It was painted where the temp was about 70, and it stayed in the 70 degree room all through the night.

Did I do something wrong? I'm emailed their tech support, but I haven't heard back from them yet. Just thought I'd check here. It was only a test piece, so it's not critical, but I'd sure like to know what I did wrong. Normal 1 1/2" brush from Lowes or somewhere. A Purdy or Wooster, $15 brush.

Thanks-
Steve

 

[Shovelhead]

Did you thin it with reducer?

 

[CES020]

Nope. Just brushed it right out of the can.

 

[J Hill Designs]

sounds like you needed another coat of primer...edit: the sanding probably broke through the prime layers

 

[Biker Scout]

Next time, spray a fine mist of Lacquer Thinner over your wet paint.

 

[Shovelhead]

Nope. Just brushed it right out of the can.

You have to thin it....not sating that's why you have bubbles....but it needs to be reduced to the consistency of cream.

 

[CES020]

Alrighty then, I'll give it another try! I'll sand that coat and put another coat on top, thinned with their reducer.

 

[Biker Scout]

Be sure to degrease your surface after you sand. That comes right off the 1Shot website.

 

[Jillbeans]

I would not spray it with lacquer thinner for fear of it getting thru to the SignFoam and damaging it.
I hate making SignFoam signs, but never had the issue you described. I just used regular Kilz or Zinsser primer tho. I wonder if you would be better off using a good latex house paint as a top coat? I could never get the 1S to have an even gloss on sandblasted SF.
Love....Jill

 

[JR's]

sounds like you needed another coat of primer...edit: the sanding probably broke through the prime layers

I concur with Jhill.

JR

 

[CES020]

One more point. I picked the piece up, went to sand the surface with fine sandpaper and when I stopped sanding, there was a big fat fingerprint embedded where I held it. I took my fingertip and pushed into the paint at an angle and it actually moved the paint, opening up the top layer and I got paint on my finger.

I'm guessing I put it on about 5 times thicker than you are supposed to and I didn't dry all the way through, hence the top layer drying and then the tiny bubbles trying to get out of the wet coat under it.

Does that sound like a reasonable cause?

I'll post what 1-Shot says when I get that reply.

 

[wesley]

defintely sounds like solvent pop. the solvents in the paint trying to get out but the dry layer of film at the surface is keeping that from happening. defintely try to put 2 or 3 thin layers rather than 1 thick layer, with plenty of dry time between coats.

 

[Jillbeans]

If you put 1S on too thick it can wrinkle.

 

[BobM]

I would think the primer wasn't fully cured or when you "wiped it down" the thinners you wiped with or the primer thinners weren't fully evaporated and are now trying to migrate thru the One Shot.

 

[Billct2]

I'm with Bob on this one, too thick a top coat can cause a lot of problems, but usually bubbles is not one of them.

 

[CES020]

1-Shot folks weighed in and from what I told them, they believe the primer was not dry enough.

 

[Gino]

If you put two coats of prime on and then sanded it [which I have no idea why you did that], your sandpaper or pad would've gummed up.

Based on how you said your finger moved the paint around... I really believe you just had too much paint on there. What happens is, your paint will dry throughout at a steady pace and as the drying agents are being released it will harden. In your case, the paint was drying and created a shell on top and the trapped paint below couldn't let any more solvents pass through so they pushed up creating many many little bubbles and they couldn't break the surface, but now you have dry paint with a gummy underside. That will probably take years to dry. Ask me how I know... LOL

This is really a true example of outgassing.

 

[J Hill Designs]

was that the FSC-88 WB (waterbased)? It seems like you would notice that it wasn't dry when you sanded it...did it ball up or anything?

 

[CES020]

If you put two coats of prime on and then sanded it [which I have no idea why you did that], your sandpaper or pad would've gummed up.

I did put 2 coats of primer on and sand it because the people that make the primer say not to sand between coats of primer, and the first coat wasn't thick enough to cover. I followed their instructions on application. The sandpaper did not gum up at all. They state you should put it in front of a fan for 4 hours to dry it. I put it right in front a fan for several hours, and it was a small test piece, so I assumed it was dry. I sanded a little spot, it sanded just like they said it should, where it turned into dust instead of gumming up the paper, so I thought I was okay.

Yes, it is the WB version. It's my first time trying it, so I was just seeing how it all worked together as a learning experience, which it has been!

 

[Just Another Sign Guy]

just a note myself i am not a fan of that primer or the 'other' big name hdu primer i'm trying not to throw anyone under the bus here. what i have found is that by moving to a higher pound of hdu i can finish it with kilz or NO primer at all and the holes are small enough that they are filled with the paint.