Bubbles

[guiwee]

Short and to the point(307 wrc pug)
1.no primer...sand wash rinse and dry
2.3 mist coats..2 wet coats(straight from can) ts-17
3.Overnight in dehydrator (approx. 24hrs give or take)then a week in box
4.Body fine..few particles nothing to big...
5.Warm body and can in dehydr.(ts-13)
6.Spray 2 mist coats 2 wet..20min between coats(in 1 case an hour)
7.Look in an hour later and lo and behold on the rear bumper just below trunk there is a row of small bubbles going from middle to right towards
right rear taillight!!! And seemingly going from small to big for about inch and a half

Im curious as to what may be the cause? I dont think drying time was an issue. I know the ts-13 doesnt react with ts-17. The area was free of contaminants before spraying. No other area of car exhibits these bubbles.
What could be the cause? Better yet how to fix? Strip paint? Can I sand them out? Never had this before. Will try to take pic in daylight on the morrow

[Adam Baker]

Ive had this problem w/ Tamiya paints in the past, and it was always from putting the paint down too thick.

Ive always gone back and carefully sanded down the affected areas, and repainted them.

[CrateCruncher]

In addition to better control over volume sprayed, decanting TS lacquers into an airbrush cup allows any dissolved propellent time to outgas before hitting the surface of your model. I don't have enough info to be confident that this is what happened in your case but it is worth consideration.

[ZoomZoomMX-5]

The bubbles are from the propellant that's still in the paint when it lands on the surface. If you get a really nice wet coat, you might find a few bubbles pop up just as your found from being a bit too aggressive w/the paint can. There's a fine line between a nice, smooth coat and getting it just a bit too close/too wet and ending up w/some bubbles, and those bubbles seem to appear as the paint settles and starts to cure.

I mostly decant these days, saves paint and aggravation.

[guiwee]

Originally Posted by CrateCruncher

In addition to better control over volume sprayed, decanting TS lacquers into an airbrush cup allows any dissolved propellent time to outgas before hitting the surface of your model. I don't have enough info to be confident that this is what happened in your case but it is worth consideration.

I dont have an airbrush regretablly Hey apparently I havent mastered the spraycan yet!!! But im close

[guiwee]

Originally Posted by ZoomZoomMX-5

The bubbles are from the propellant that's still in the paint when it lands on the surface. If you get a really nice wet coat, you might find a few bubbles pop up just as your found from being a bit too aggressive w/the paint can. There's a fine line between a nice, smooth coat and getting it just a bit too close/too wet and ending up w/some bubbles, and those bubbles seem to appear as the paint settles and starts to cure.

I mostly decant these days, saves paint and aggravation.

So basically I was too close? Sure did look like a really good wet coat though..maybe too wet.I thought the sure sign of paint too thick
was the paint running.. Thanks for the info!!! Will watch myself more
carefully next time!!

[ChillyB]

You should be able to sand the bubbles out without a problem. I had the same thing happen on a Porsche I'm working on. Just a few bubbles appeared and I sanded them away and used Tamiya polishing compound to bring back the gloss without having to repaint.

[ZoomZoomMX-5]

Originally Posted by ChillyB

You should be able to sand the bubbles out without a problem. I had the same thing happen on a Porsche I'm working on. Just a few bubbles appeared and I sanded them away and used Tamiya polishing compound to bring back the gloss without having to repaint.

Sometimes that's sufficient, though sometimes it requires a scuff/respray. Every job is different. A model I built a little over a year ago required respray; the paint ran a little and as it dried a bunch of bubbles appeared, I had a very limited amount of time to fix it (24 hour Jag D Type build), so I dehydrated it several hours, sanded, spot repaired the area, re-shot the clear over the whole car a bit more carefully. The extra clear ended up making the whole car a bit smoother overall, so it wasn't a lost cause.

[drunken monkey]

Originally Posted by guiwee

So basically I was too close? Sure did look like a really good wet coat though..maybe too wet.I thought the sure sign of paint too thick
was the paint running..

Maybe both.
If you are too close you will tend to spray heavier.
But you can just easily spray too much paint from a further distance.

For point of reference, I spray at about 8 inches from can to body.
There's a short clip of someone spraying from can on Tamiya site somewhere that someone posted a link to before.
That is about how fast I spray.

Finally, TS 13 reacts with pretty much everything.
I have never had a good experience with TS-13 over TS-17.

I'm also not sure if you even actually need to clear over Gloss Aluminium paint; the clue being in the name. In fact, I've had pretty good experiences with sanding and polishing TS-17.

[guiwee]

Originally Posted by drunken monkey

Maybe both.
If you are too close you will tend to spray heavier.
But you can just easily spray too much paint from a further distance.

For point of reference, I spray at about 8 inches from can to body.
There's a short clip of someone spraying from can on Tamiya site somewhere that someone posted a link to before.
That is about how fast I spray.

Finally, TS 13 reacts with pretty much everything.
I have never had a good experience with TS-13 over TS-17.

I'm also not sure if you even actually need to clear over Gloss Aluminium paint; the clue being in the name. In fact, I've had pretty good experiences with sanding and polishing TS-17.

Yeah but when I say react I mean in a negative way!!
Especially if the paint has been dry for at least a week right?
Thought you guys said its cool to spray ts-13 anytime after the paint is dry
About ts-17..it never seems to dry glossy for me no matter what I do..I think Im not alone when I say this either. Ive read of a couple of people
who also had,while not quite a problem per se,were disappointed with the results. ts-17 and ts-30 Ive used interchangeably from time to time.
Ts-30 seems to have more "luster".more of a shine...at least to me.

[KevHw]

The paint layer needs to be cured/dried before a clear layer goes on top. That's just standard procedure.
It's not that TS-13 is fine over paint that has dried; it's that it is a very hot (contains a strong thinner) paint and so will eat into anything underneath it if applied too heavily. It's like pouring paint thinner over a body you've painted a long time ago...it'll still eat the paint away.

I'd have done a lot more mist coats before even applying any wet ones. Normally, I'll apply about 3-4 mist and then build up wetter coats, not jump straight from mist to wet, if you understand what I mean.

[ZoomZoomMX-5]

Originally Posted by KevHw

The paint layer needs to be cured/dried before a clear layer goes on top. That's just standard procedure.
It's not that TS-13 is fine over paint that has dried; it's that it is a very hot (contains a strong thinner) paint and so will eat into anything underneath it if applied too heavily. It's like pouring paint thinner over a body you've painted a long time ago...it'll still eat the paint away.

I'd have done a lot more mist coats before even applying any wet ones. Normally, I'll apply about 3-4 mist and then build up wetter coats, not jump straight from mist to wet, if you understand what I mean.

Actually applying mist coats of TS 13 over fresh TS color paint is a good way to get it to meld better w/the underlying coats to prevent problems from applying TS 13 too quickly. It's trickier w/just the spray can, it's incredibly easy when decanting/airbrushing. In fact when I shoot gloss aluminum (or any metallic/pearl) decanted, once I'm "done" with color coats I mix some clear w/the color and shoot a few light midcoats, before going w/all clear. It helps provide a barrier if the TS goes on a bit too heavy. I'm also starting to decant/shoot a layer of B501 Mr. Topcote over the Tamiya clear/color mixture before shooting pure TS 13. This makes applying wet coats of TS 13 quite safe, as B501 is a great barrier coat. No worries over the color pulling away from panel lines, no worry of the color getting mottled.

[KevHw]

I can understand for solid colour coats it would be alright to spray TS-13 over fresh paint but I would have thought for metallic paints it could risk causing some of the metal flakes to shift and loose some of the reflective finish. I know you said mist coat it, but then I'm assuming the fresh paint would still be quite tacky to the touch?
I like the idea of mixing some clear with the colour paint, before going to all clear, as it must give the paintjob a nice semi-candy and deep/wet finish . I'll definitely try it out with metallics since you have good results but I'm still dubious about it.

[Didymus]

Originally Posted by guiwee

So basically I was too close?

And too slow! A deep pool of wet paint can produce a case of the bubblies. Wet is okay on top of mist coats, but it's risky because it's so hard to control the volume. A safer approach is to stick with moderately wet/dry coats. It's easier to rub out a little orange peel than it is to de-bubble your final coat.

Ddms