Question about 1 shot and hardener

[JR's]

Question about 1 shot and hardener.

I need help from all you paint gurus.
Brand-new half pint one-shot.
Hardener
and low temp reducer.

While applying the lettering I am getting tiny bubbles on the surface.
First time this has happened to me I am stumped.
Any help I would greatly appreciate it.

Thanks in advance
JR

 

[BIG EASY DOES IT]

Previous post. Might be the reducer

Bubbles in 1shot paint

 

[Gino]

Not knowing your level of knowledge, it sounds like you either have some contaminant in it or you are contaminating it with something you are adding from too much hardener or reducer to oil still in your brushes. Too much additives can really mess with your paint results. Also, are you spraying, brushing or using a roller ?? When using the combination you mentioned, if memory serves me correctly, one is cancelling out the other in your case, that's why I asked what you are doing.

 

[JR's]

graduated measuring cup, clear. Followed one-shot recommendations for mixing.
Gray squirrel lettering brush. Brush was cleaned with Terps then finished cleaned with reducer.
Just enough reducer to get the paint to flow.
Was lettering outside. Surface was prepped.
Added the hardener because the lettering will be cleared over.

Been hand lettering on and off since 84

thank you

 

[JR's]

It doesn't appear to be fish eyes, or contamination from silicone oils or wax.
But I could be mistaken

 

[Gino]

Try doing nothing to the paint, but use a totally brand new brush, never used. Paint a surface you know 100% is completely clean. If no bubbles, go to the surface you were painting with the problems. See if the problems arise, again. Do it outside. Seems a little cool for painting and perhaps the additives are playing with the adhesion. Don't really know, just shooting in the dark, here.

I hand-painted outside lotsa times, but generally not in anything under 50º on vehicles or signs. Walls are a different thing.

Are you lettering or striping ??

 

[JR's]

Thanks Gino for your help.

Lettering on a fiberglass boat transom.

I have to add the hardener, the lettering is going to be cleared over with urethane.

I pallid the paint out on several different pallets, and they all had little bubbles. Went with a different brush, but not a new one. That is usually my test.

I told him it was too cold outside but they did not have a lift available to bring the boat inside.
Yada yada from the yard crew.

I didn't think the cold would cause bubbles but I did know it was going to slow down the drying time.

Thanks again for all the help.
Going back tomorrow to have another whack at it.

 

[Johnny Best]

Don't use the reducer to thin your paint. Just use turpentine to thin and flow out your paint. And don't use reducer to clean your brush. No hardener either. If you stop getting bubbles then add the reducer and hardener to see if bubbles come back. Are you painting letters or a large area.

 

[JR's]

Thank you Johnny,
8" letters

 

[Johnny Best]

Are you using a flat for those size letters. You can "tip" those bubbles down after they dry for about 5 or ten minutes.

 

[signbrad]

Here are some more observations.
My experience with bubbles is that they are often caused by introducing air into the film—such as when rolling with a foam roller sleeve. But I have also seen bubbles from brushing paint that has been over-reduced.

Are the bubbles really bubbles—or separations? Paint that separates or crawls can be caused by a surface contaminant. And I recall that sometimes the gelcoat on a fiberglass boat can act as if is contaminated when really it isn't. That's why I always abrade the gelcoat rather than just clean it with solvents. Bon Ami soap was my go-to abrasive for cleaning and I rubbed pretty hard.

Finally, the cold may be an issue. A smooth, cold surface can cause paint to try to crawl.

One Shot 4007 Hardener is compatible with the One Shot reducers. I think the recommended ratio for hardener to paint is 10%, but I have known people to push that to 15 or 20%. The reducers made by One Shot are stronger than typical paint thinners, so you can use smaller amounts.
Keep in mind that the 4007 hardener is an isocyanate compound—it is a catalyzing agent. https://docs.matthewspaint.info/safety-data-sheets/pdf/1shot/4007.pdf Cold is an enemy of catalyzed paints. Matthews Paint, in their paint manual, says that their Acrylic Polyurethane should not be applied in temperatures below 60 degrees. The cold kills the catalyzing and it does not start back up once it dies. Such a paint film, not being truly catalyzed, might not have the hardness needed to receive a catalyzed clear laid on top of it without lifting.
Would this be the same with catalyzed One Shot applied in weather too cold? I would expect so, but I've never done it.

Brad in Kansas City