AMT Challenger Paint Crazing....

[Len Geisler]

I hope someone can shed some light for me....

Tonite I picked up my second AMT Challenger, why you ask, not beacuse I am following through with my idea for several R/T's in some traditional colors, but becuase I have an etching problem...

I posted a few days ago asking if anyone had some issues with crazing on the new kit, and I was the only one with the issue, so i chaled it up to expirence and began again. I wet sanded the body, got another brand of paint and went at it again, this time, there was no sign of crazing till I added the clear, makes sense to me, as the clear brings out all the flaws..

here is what I did, Duplicolor grey sealing primer, dried for a couple days then wet sanded. After the wet sanding, washed it in warm water with no soap, just to remove the sanding film. Shot some Tamiya paint and BAM crazed the body...So with that said, I waited a couple days and reshot the body this time with Plastickote T235 (my norm BTW). Wet sanded it nice and smooth, then shot some Testors Auto Lacquer and I seemed to have a nice finish, a little matt when dry, but nice looking. Fast forward a couple days, and I took the hood, brushed on some Future, next when dried, BAM those crazing marks were back...

What I'd like to know is what primer and paints you have used with out trouble. I have seena bunch of suit builds so I am sure someone can shed some light on this for me...

As always, thanks in advance for any and all info!!!

[Zoom Zoom]

When you use a hobby paint like Tamiya or Testors you don't need to pull out heavy artillery for primer, such as any Duplicolor primer. That stuff is terribly harsh on plastic. Especially the primer/sealer if it's laid down first.

I've painted two AMT Challengers w/Tamiya sprays, I used Tamiya fine gray primer on one, and Testors Italian Red lacquer as the primer on the second, as a base coat for Tamiya Mica Red. No crazing whatsoever. There's enough sanding of the mold lines that if you do use an automotive primer you'd best use some sort of sealer, like BIN, or Future (BIN over primer, Future can go on bare plastic or a layer of primer), or liquid styrene cement and then primer, or whatever concoction you like. Spraying Duplicolor primer/sealer first is a recipe for disaster. It's best applied over other primer. And generally best to avoid if you're using mild hobby sprays like Tamiya or Testors.

Some of my best/easiest paintjobs are when I shoot Tamiya or Testors sprays over bare plastic w/o any primer. Primer has it's place, but it's not necessary all the time.

How to fix it if you're in the color stage? I've been known to shoot a layer of Future or decanted Gunze B501 Mr. Topcote or properly thinned Gunze solvent-based acrylic clear onto a body that's painted/crazed (and sanded smooth) to stop the damage. Then I shoot a thin layer of color so it's all even, then go onto clear. To me stripping paint is the last resort.

[Zoom Zoom]

I painted my Challenger last week with auto laquers with no problems. , , until I put too much clear on it and screwed up the pearl coat I put on it. , , But no crazing or ghosting at all.

I've learned the hard way about clearcoats and have a new system that's working quite well. I shoot a lot of Tamiya paints, and I prefer Tamiya TS13 as my clear on just about everything. But it will eat colors if applied too aggressively, as in a good final wet coat. It might screw up the metallic/pearl, it might cause the paint to get thin over panel line edges.

Between my color coat and my Tamiya clearcoat I apply a few light coats of decanted Gunze B501 Topcote or it's bottle equivalent which is their new solvent-based acrylic clear. This is a good base for clear, it doesn't attack the paint underneath, and it seems impervious to wet coats of Tamiya TS clear. I like airbrushing the first coats of Tamiya clear, and then applying a couple wet coats straight from the can to finish up. Often this is so smooth it allows me to skip any scuffing w/micromesh before using Tamiya compound.

[MikeMc]

When you use a hobby paint like Tamiya or Testors you don't need to pull out heavy artillery for primer, such as any Duplicolor primer. That stuff is terribly harsh on plastic. Especially the primer/sealer if it's laid down first.

I've painted two AMT Challengers w/Tamiya sprays, I used Tamiya fine gray primer on one, and Testors Italian Red lacquer as the primer on the second, as a base coat for Tamiya Mica Red. No crazing whatsoever. There's enough sanding of the mold lines that if you do use an automotive primer you'd best use some sort of sealer, like BIN, or Future (BIN over primer, Future can go on bare plastic or a layer of primer), or liquid styrene cement and then primer, or whatever concoction you like. Spraying Duplicolor primer/sealer first is a recipe for disaster. It's best applied over other primer. And generally best to avoid if you're using mild hobby sprays like Tamiya or Testors.

Some of my best/easiest paintjobs are when I shoot Tamiya or Testors sprays over bare plastic w/o any primer. Primer has it's place, but it's not necessary all the time.

How to fix it if you're in the color stage? I've been known to shoot a layer of Future or decanted Gunze B501 Mr. Topcote or properly thinned Gunze solvent-based acrylic clear onto a body that's painted/crazed (and sanded smooth) to stop the damage. Then I shoot a thin layer of color so it's all even, then go onto clear. To me stripping paint is the last resort.

Bob hit it right on (as always )

I shoot a lota duplicolor and learned never to put primer sealer down first...always over a solid , dry primer...it even says this on the label

[BigGary]

Bob hit it right on (as always )

I shoot a lota duplicolor and learned never to put primer sealer down first...always over a solid , dry primer...it even says this on the label

I've never had paint craze. I use cheap Wal-Mart $2 primer and whatever paint happens to be available, everything from Krylon-$4- to cheap stuff from Big Lots, Ollie's, or whatever-99 cents. The biggest problem I've had with these paints is that the nozzle is not designed for small objects like car bodies. For that the airbrush comes in handy.

As Zoom Zoom points out, you don't need killer primer and paint on plastic, They are just too "hot" for styrene. Maybe the Challenger needs a trip through the purple pool and start again.

Gary

[Len Geisler]

When you use a hobby paint like Tamiya or Testors you don't need to pull out heavy artillery for primer, such as any Duplicolor primer. That stuff is terribly harsh on plastic. Especially the primer/sealer if it's laid down first.

I've painted two AMT Challengers w/Tamiya sprays, I used Tamiya fine gray primer on one, and Testors Italian Red lacquer as the primer on the second, as a base coat for Tamiya Mica Red. No crazing whatsoever. There's enough sanding of the mold lines that if you do use an automotive primer you'd best use some sort of sealer, like BIN, or Future (BIN over primer, Future can go on bare plastic or a layer of primer), or liquid styrene cement and then primer, or whatever concoction you like. Spraying Duplicolor primer/sealer first is a recipe for disaster. It's best applied over other primer. And generally best to avoid if you're using mild hobby sprays like Tamiya or Testors.

Some of my best/easiest paintjobs are when I shoot Tamiya or Testors sprays over bare plastic w/o any primer. Primer has it's place, but it's not necessary all the time.

How to fix it if you're in the color stage? I've been known to shoot a layer of Future or decanted Gunze B501 Mr. Topcote or properly thinned Gunze solvent-based acrylic clear onto a body that's painted/crazed (and sanded smooth) to stop the damage. Then I shoot a thin layer of color so it's all even, then go onto clear. To me stripping paint is the last resort.

Bob,

Thanks again, as always, for the sound advice....I sometimes get ahead of myself when doing things and dont think them out clearly...After this "reality check" I can remember shooting some Tamiya and Testors paints over bare plastic and being quite happy....I will prep my new body by removing mold lines and cleaning the seams and shooting the Tamiya on the bare plastic...And as for the paint stripping, I am with you 100% that is a last resort for lots of reasons.

I will post some progress once we dry out enough for me to paint again...

Tks again

[Zoom Zoom]

Bob,

Thanks again, as always, for the sound advice....I sometimes get ahead of myself when doing things and dont think them out clearly...After this "reality check" I can remember shooting some Tamiya and Testors paints over bare plastic and being quite happy....I will prep my new body by removing mold lines and cleaning the seams and shooting the Tamiya on the bare plastic...And as for the paint stripping, I am with you 100% that is a last resort for lots of reasons.

I will post some progress once we dry out enough for me to paint again...

Tks again

The two Challengers were painted because one gave me nothing but trouble; it was a rainy, damp week and nothing went right. The second one was painted in much better conditions, and came out perfectly in about 1/4 the amount of time.

The first body (primed Tamiya gray, coated w/Testors Italian Red, Tamiya Mica red, Tamiya clear red, Gunze clear, Tamiya clear) that had problems was stripped the other day in 99% rubbing alcohol, and it came off pretty quickly. It was stripped because I needed the body for parts and it was going to be combined w/another body that is raw plastic.