Why did this paint bubble?

[Captain Mark]

Hi folks,

Yesterday I was using Tamiya TS-13 clear lacquer straight from the can. I normally do this if I need a thick layer of clear on the part (But always mist coat a few layers from the air brush first, especially if there's decals there).

So I place the can on a hot driveway in the sun to warm it up a little, then shake it well for a minute or so. First hit the part with a medim coat, then after a few minutes put on a heavy coat.

To my surprise once I'd put the heavy coat on I noticed that it had actually bubbled, or perhaps frothed is a better term. Think of a fizzy drink, you can see the bubbles in the surface of the liquid. There were about 7 to 8 tiny airbubbles sitting in the clear paint, and they just weren't popping. I'm not sure if the paint was just too thick, or if I shook it too much... I just don't know.

Anyway, I didn't get a picture of this as I was pain stakingly using a toothpick of all things to very lightly touch each bubble to force it to pop. To my great relief I was successful, and the results of the clear coats have come out very nicely. But it was real panick mode for a little while...

I've never come across this kind of thing before - can anyone give me any idea of what causes it, or how to avoid it in the future???
I didn't get the impression that it was a reaction of anykind, simply airbubbles in the paint - almost like it was trying to gas out but some of the bubbles got stuck.

Anyway... here's a link to a pic of how some of the good work came out...
http://s200.photobucket.com/albums/a...ent=RB1061.jpg

Input or advice on how to avoid this problem again would be great, 'cos I don't want my heart to stop again while I pop those darn bubbles in fast drying clear paint!

Cheers all,
Mark

[Veyron]

The only time Tamiya paint bubbles is when it is put on too heavy. If the can was quite warm you probably got a heavier shot than you intended and the 'gas' gets trapped in the paint because it is already 'flashing' before the bubbles can dissipate.

[cyberkid]

Mist, mist, mist for about 5 or 6 rounds before I even put on a light coat. You were lucky that the TS-13 didn't attack your decals. TS-13 is infamous for attacking decals. But like Veyron said, to heavy a coat too quickly.

[ZoomZoomMX-5]

Too heavy a coat, shot too close so the propellant didn't dissipate before it hit the surface. Fairly common w/Tamiya sprays.

[klutz_100]

Originally Posted by Captain Mark

Input or advice on how to avoid this problem again would be great,

Avoid TS13 and use Gunze clears instead

I am not meaning to be smartass.

I KNOW it is possible to get great results with TS13 but the truth is that it is a terribly temperamental clear and it's mixed reputation didn't just materialize out of nowhere and neither did the zillion posts about TS13

How many posts do you recall reading about temperamental Mr Top Coat...?

My philosophy is that TS13 is just not worth the risk when there are so many good alternatives out there

My very subjective

[stevenoble]

Originally Posted by klutz_100

My philosophy is that TS13 is just not worth the risk when there are so many good alternatives out there

My very subjective

[ZoomZoomMX-5]

Originally Posted by klutz_100

Avoid TS13 and use Gunze clears instead

I am not meaning to be smartass.

I KNOW it is possible to get great results with TS13 but the truth is that it is a terribly temperamental clear and it's mixed reputation didn't just materialize out of nowhere and neither did the zillion posts about TS13

How many posts do you recall reading about temperamental Mr Top Coat...?

My philosophy is that TS13 is just not worth the risk when there are so many good alternatives out there

My very subjective

I've had Gunze Mr. Topcoat (B-501) froth before when sprayed too close. This wasn't a case of bad paint, it was "operator error".

All this hatred towards TS-13; I don't understand...I've never had trouble with it, either airbrushed or from the spray can, unless I've done something stupid, like lay too heavy a coat on. I will admit that I'm more inclined to use Mr. Topcoat on a model w/decals, but I've been successful spraying Tamiya TS 13 over decals by building it up slowly (w/airbrush) and avoiding doing a wet coat. Spray it that way and it should also work over enamel.

I do love Mr. Topcoat, but I love Tamiya TS 13 as well. I'm not a big fan of automotive clears, I've had too many problems with them.

[Veyron]

Originally Posted by ZoomZoomMX-5

I've had Gunze Mr. Topcoat (B-501) froth before when sprayed too close. This wasn't a case of bad paint, it was "operator error".

All this hatred towards TS-13; I don't understand...I've never had trouble with it, either airbrushed or from the spray can, unless I've done something stupid, like lay too heavy a coat on. I will admit that I'm more inclined to use Mr. Topcoat on a model w/decals, but I've been successful spraying Tamiya TS 13 over decals by building it up slowly (w/airbrush) and avoiding doing a wet coat. Spray it that way and it should also work over enamel.

I do love Mr. Topcoat, but I love Tamiya TS 13 as well. I'm not a big fan of automotive clears, I've had too many problems with them.

Agreed. I have also bubbled Mr. Topcoat.

[stevenoble]

My philosophy has always been to keep it simple and to use compatible products and not 'mix and match' So if you use Tamiya paints use Tamiya clear.If you use Zero paints use Zero clear and so on.By keeping to this rule I've not had too many problems along the way.I think by doing it this way there is less chance of any adverse reactions because the paints from the same range are designed to work together.I don't use enamels or acrylics for body painting anymore,but I use them for all the other parts of a kit.I prefer the Tamiya TS range or more recently Zero basecoat paints as they just work better for me.The best way with clearcoats is to try them all then see which one you prefer,what works best for you might not be someone else's first choice.
I've had the 'bubbling problem' described with TS 13 myself,but also with Mr Topcoat sprays as well.Caused I'm sure by me laying on the clear too heavily and spraying too close.Usually as it drys the bubbles disappear.If not I flat them out with 1500 wet and dry and spray more clear to correct the problem.

[klutz_100]

Each to their own...

[rsxse240]

This is exactly what the guy from Valspar told me about spray cans: The only time you should really warm your paint cans is if they are a good ways below room temp (75-90 degrees F.) because it forces more paint out when it's hot, then it cools and sprays less paint. When the can is warmed up it creates alot more pressure inside which will force the paint out faster, and not give it enough time to "gas out" the propellant before it hits your surface, then it creates bubbles, just like a can of soda being spilled on a table, only the bubbles won't pop.

[robrex]

Mark,
You're holding out on us by not posting a progress thread on this! When can I see this model?

[klutz_100]

Originally Posted by robrex

Mark,
You're holding out on us by not posting a progress thread on this! When can I see this model?

I'm wondering if the build is not going to be published?

[Captain Mark]

No formal progress thread on this one unfortunately, or, as it turns out, Mr Dietrich Matesich will take a big legal stick to me. So klutz_100 has hit the nail on the head.

But, you can click the link in my sig for updates. If you've not checked it out yet then you've missed a bunch of stuff! I'm getting quite a bit of modeling done lately so hopefully this one will be finished quickly and I can then make a start on this years Honda RA107!!!

And thanks for the replies and info folks, very helpful!

[Didymus]

Originally Posted by ZoomZoomMX-5

I do love Mr. Topcoat, but I love Tamiya TS 13 as well. I'm not a big fan of automotive clears, I've had too many problems with them.

After comparing automotive clears with clear lacquer, and hearing some pretty convincing arguments in favor of lacquer, I've switched to decanted TS-13. On my first try, I too got bubbles by airbrushing it too wet and heavy, in a hopeless attempt to get instant high gloss like you get with urethane clear coat. Well, that's just not going to happen, but if I spray the TS-13 slightly thinned, I get a surface that's nearly free of o-p; it doesn't load the edges or fill the detail, and when polished, it looks more realistic.

My question: What about good ol' Testors Glasscoat Clear Lacquer?

Any problems with it? Is it as glossy as TS-13 and Mr.Topcoat? As easy to polish? I have an old supply of it that's turned brown. I'm planning on using new stuff, but will my white Cunningham be a yellow or brown Cunningham (awk) in five years?

Thanks in advance for any warnings or tips.

Diddy