Fish Eyes

[paullap]

Hi I have been having a nightmare, I have made a lazy Susan for my daughter, I made it from maple and stained it dark oak, Looks great until I started to paint it, I sanded it ,then stained it, and then sprayed it with Miniwax satin polyurethane, I got some fish eyes in the surface, So I sanded it again, re sprayed it and had about 4 or 5, so I let it go off a bit and thought I would give it a quick final coat, Then it was covered with these bloody things, What am I doing wrong?.


Paul

 

[Housey210]

spray, tin or compressor?

 

[paullap]

Fuji semi pro , new

 

[profchris]

Usually contamination of some kind. Oil or grease in your spraying kit sounds most likely. Surface contamination keeps the fish eyes where the contamination is, not all over.

A good clean up and try again?

 

[Sgian Dubh]

Also known as cratering or crawling. As profchris says there's contamination, e.g., silicone, oil, grease all being possible. The contaminant(s) could be on either the surface you're finishing and/or the gun. As he says do a clean up and try again.

A rather desperate measure is to add anti-cratering additive (silicone) to your finish. It's desperate because after using this stuff your gun definitely has long-term silicone contamination and it's likely most or all subsequent spray finishing with that gun may need the addition of silicone to avoid fisheye/ cratering/crawling. Slainte.

 

[paullap]

Ok, I rubbed it all down really well using 240 grit, I think I should have gone a bit finer to finish, a quick coat and Perfick, Looks absolutely stunning, A good coat of wax tomorrow and the deliver to me daughter on Sunday, Thanks again for the help guys.

Have a good weekend

Paul

 

[Sgian Dubh]

Ok, I rubbed it all down really well using 240 grit, I think I should have gone a bit finer to finish,

Paul

240 grit is more than fine enough for film forming finishes such as, in your case, varnish. It's a myth that surfaces need to be sanded to silly numbers like 1,000 or 4,000 grit prior to applying a polish, especially if working with coarse textured ring porous wood species. Sanding to somewhere between 180 grit (coarse timber, e.g., oak) and 220 - 240 grit (fine textured diffuse porous timber, e.g., maple) is more than adequate. The reason is that the size of the abrasive material used in finer abrasive grades is smaller than the voids or gaps found within the texture of the wood.

Anyway, I'm glad you seem to have fixed the problem. Slainte.