Fisheye attack.

John P · Post by **John P** » Sun Mar 16, 2014 9:28 pm

Okay, I can NOT understand this one:

12" C-57D styrene kit, with lights. The plan is to give it a coat of Tamiya metallic black as a light blocker, then Tamiya Mica silver, both from spray cans, because Tamiya laquer always comes out so beautifully smooth.

I wash the plastic parts thoroughly with dish detergent and let it dry 24 hours.

I give the top of the saucer, and the bottom of the saucer, one light coat of metallic black each. It dries smooth and beautiful.

I wait 24 hours and give the bottom of the saucer a second coat of black, a little heavier. It also dries smooth and beautiful. A while later, I give the top of the saucer its second coat.

It bubbles and fisheyes. All over. What. The. Hell?

There is NO difference in what that layer of paint was covering, than the paint on the other half which came out fine.

Temperature in the room was nominal, and the same for each application. All I can think of is I didn't shake the can enough? Maybe because the can was almost empty I got propellant mixed in? I'm at a loss to explain it.

Lt. Z0mBe · Post by **Lt. Z0mBe** » Mon Mar 17, 2014 12:07 am

If I had to guess I would say the can wasn't shaken enough on the first coat of the top and had an abundance of solvent. Second coat likely wasn't shaken enough too. This means you have a solvent-heavy first coat which would still possibly be outgassing. The second coat also has an abundance of solvent relative to its binder. It's trying to dry over a glossy, possibly outgassing first coat. Too much solvent means the full crosslinking of the binder can't occur - at least not over a glossy, possibly gassy substrate.

I hope this helps.

Kenny

Chas · Post by **Chas** » Mon Mar 17, 2014 8:08 am

I usually place the cans in HOT water upto about the half way point for 5-10 minutes after I've shaken it for a solid minute. Then I shake it for another minute before I begin spraying. The Tamiya spray cans are terrific, but I try not to take their great performance for granted.

John P · Post by **John P** » Mon Mar 17, 2014 8:23 am

That's an awesomely thorough explanation, Lt.

I'm being careful, shaking a lot (me AND the can!) and letting it dry more between coats on my second try.

John P · Post by **John P** » Tue Mar 18, 2014 12:05 pm

So far so good, btw. A coupla coats of black, a coupla coats of silver, nice and smooth.