Problem with Testors clear coat

QUOTE: Originally posted by Se7eNE What should I allow for drying time on coats prior to clear coating? I'm still green behind the ears ;)

I always follow the 48 hour rule:

I paint the model, wait 48 hours, spray it with Future, wait 48 hours, decal it, wait 48 hours, Future it again, wait 48 hours and then give it a final coat of flat clear.

Mike

QUOTE: It could be the paint reacting with the Release

Good point ... did you clean the parts before painting? They nearly always have a little bit of grease on them that is used to release them from the molds. Acrylics hate that stuff and don't adhere well at all if it isn't washed off before painting.

QUOTE: Thanks music. Lots of good info there.

Glad to be of service. If you figure out what caused it let me know. You've got me curious now.

Thanks music. Lots of good info there.

It could be the paint reacting with the Release....

QUOTE: It was a coat of Testors Gunship Grey. I had made the(late) choice to gap fill after the fuselage was assembled(my first kit in over 10 years, albeit a serious attempt at high quality). So the pieces that made the fuselage were pre-painted as opposed to filling seams, assembling the body and THEN painting the plane, hehe. I did it all bass ackwards. Well, it was a great learning lesson. The A-10 I started last night doing it the correct way is looking great and I'm really satisfied with the tips I've gotten from this site. Anyhow, it was painted already. I ended up doing a repair job on the seams. I had horrible scratch marks that no matter how much I sanded and polished they wouldnt go away. Clear coat made them dissapear thankfully with the exception of the bubbling.

Nothing really wrong with that. One of the reasons I prime things is to find surface flaws that I thought I had cleaned up properly. You just primed and then filled the gaps! As long as your color coat is opaque and there are no glaring differences between the prime coat and the seam filler, it will never be noticeable. Sometimes even opaque paint can pick up a color cast from the colors underneath so if I have to fix something, say using white putty on a gray primer, I'll go back and spray the area I fixed just so the colors will be close to the same.

QUOTE: I had done a final coat of Gunship Grey about 8 hours prior(after the repair to the seams). What should I allow for drying time on coats prior to clear coating? I'm still green behind the ears ;)

There are a lot of factors that affect drying time; type of paint, humidity, temperature, thickness of the coat, etc. 24 hours is a general guideline, and a real dirty rule of thumb is to smell it. If you can still smell the thinner evaporating then it isn't cured yet.

QUOTE: Oddly the sidewinder missles had bubbling too on them. They were painted long before I did the clear coat and since the kit was the exact color of the missles I did not paint them, just did the fins gunmetal and the tips white. The bubbling on the missles occured on the whole missle.

Now that is odd. That being the case I don't think it was your base coat not being cured, I think it was something in the paint you used or some reaction between it and the original paint. I don't really know what caused it.

QUOTE: I ended up testing the Krylon 'Satin' which was the closest thing I could find to dull clear(for my post decal coat). It came out a bit dusty looking in certain angles of light and I don't think I'll use it again.

Although a lot of people use Krylon products, I haven't had real good results from them and I'm not a big fan of them.

I think some of their paints are laquers and you have to be VERY careful spraying laquer over acrylic. I haven't used laquer over acrylic myself, but from what I've been told even if the acrylic has completely cured you have to build up the laquer in very thin misted layers or it can cause the acrylic to dissolve.

There was a long thread about clear flats a week or so back. Here's a link to it Those posts should give you some ideas about what to use for clear coating.

QUOTE: I also have this bubbling problem with Dark Gull Grey in the small acrylic jar. If I shake it up and paint say, the cockpit tub, there's little bubbles all over it :( None of my other paints do this.

When you open the paint bottle after shaking, notice that there is usually some foam on top of the paint. That comes from air that got mixed in with the paint while shaking. Sometimes, if it isn't allowed to escape before painting, you'll get some bubbles in the paint when it is used. This is more common with hand brushing because when using an airbrush there is usually a little time spent getting things ready to go and the air floats out. Thicker paints tend to hold the air in worse than thin paints to. Usually they will pop before the paint dries and not cause any problems.

QUOTE: Here she is finished anyway:

I don't see any bubbles and it looks pretty good to me! I'm not sure what caused your problem, but hopefully it will just go away by itself.

It was a coat of Testors Gunship Grey. I had made the(late) choice to gap fill after the fuselage was assembled(my first kit in over 10 years, albeit a serious attempt at high quality). So the pieces that made the fuselage were pre-painted as opposed to filling seams, assembling the body and THEN painting the plane, hehe. I did it all bass ackwards. Well, it was a great learning lesson. The A-10 I started last night doing it the correct way is looking great and I'm really satisfied with the tips I've gotten from this site.

Anyhow, it was painted already. I ended up doing a repair job on the seams. I had horrible scratch marks that no matter how much I sanded and polished they wouldnt go away. Clear coat made them dissapear thankfully with the exception of the bubbling.

I had done a final coat of Gunship Grey about 8 hours prior(after the repair to the seams). What should I allow for drying time on coats prior to clear coating? I'm still green behind the ears ;)

Oddly the sidewinder missles had bubbling too on them. They were painted long before I did the clear coat and since the kit was the exact color of the missles I did not paint them, just did the fins gunmetal and the tips white. The bubbling on the missles occured on the whole missle.

I ended up testing the Krylon 'Satin' which was the closest thing I could find to dull clear(for my post decal coat). It came out a bit dusty looking in certain angles of light and I don't think I'll use it again.

I also have this bubbling problem with Dark Gull Grey in the small acrylic jar. If I shake it up and paint say, the cockpit tub, there's little bubbles all over it :( None of my other paints do this.

Here she is finished anyway:

Yeap, I agree with MusicCity and rjkplasticmod, I did not take into account the "undercoat" not curing long enough....

I agree with Scott. Testors top coat is a lacquer & if sprayed over a dissimilar paint that has not completely cured it can cause a chemical reaction & cause blistering or other unwanted problems. Especially using a spray can where the amount of paint is more difficult to control. I only use Testors topcoat (DullCote) with an AB & mist the first coat on very lightly. Let it set for an hour or so & repeat until you have the level of flat desired. I always let my base paint cure for at least 48 hours & several days if using a Gloss paint.

Regards, Rick

Bubbles are usually, but not always, an indication of some sort of reaction between paints or a underlying coat not allowed to cure thoroughly. If the underlying paint is still curing gas will escape causing the bubbles.

I think the Testors clear coat is a laquer (correct me if I'm wrong). What type of paint was underneath it and now long did you let it cure?

Dropping it and knocking the nozzle off is usually not a problem unless you deformed the hole that the paint comes out of. If that was what was causing the problem it would most likely be all over the entire model instead of in just certain areas.

Hmmm... Seems like you should be able to pop those bubbles with a needle..
Probably more than likely when you dropped it the tip ended up with a blemish of some sort... You could also try heating the can in a bucket of nice warm water, not real hot, just warm... it might help the paint/media flow better...