Tamiya acrylic clear problem

[p9o1r1sche]

Has anyone used Tamiya X22 acrylic clear on a body and had problems with it drying to a hard coating? I airbrushed this on a body to clear coat over decals and put it on kind of thick. After 5 days I started to polish it and found I was leaving fingerprints on areas I already polished, so I put it away for four more weeks, then started polishing again, and again the clearcoat is not hardened, leaving fingerprints from handling. Anyone have any ideas about what may have gone wrong?

[bvia]

You have to either wait (1-3 months minimum to polish out...depending on humidity level, etc) or force the issue by using a food dehydrator.

Tamiya gloss acrylic is notorious for taking several weeks-months to fully harden.

hth,
Bill

[minniebanister]

Originally Posted by p9o1r1sche

Anyone have any ideas about what may have gone wrong?

I have the same problem with all the Tamiya gloss acrylics I've tried. They don't seem to harden - even after two months. I'm living with it by just being very careful when I polish.

I've been wondering if perhaps I thin too much. I thin 1:1 (because I'm cheap and I want the expensive little bottles to last longer). I've been wondering if there is not enough binder left in my thinned paint and that maybe this is causing it to not harden.

What paint:thinner ratio do you use?

[ZoomZoomMX-5]

If you don't have a dehydrator, you might want to invest in one. I never use Tamiya gloss acrylics, so I don't know how long they take to dry on a body...but I had the same problem w/Gunze clear bottle acrylic years ago. In fact even after using a dehydrator, it would feel dry but you couldn't leave the model in a box or wrapped w/o the contact damaging the paint.

If it weren't for the decals, I'd say get some clear ammonia and soak the body to remove the Tamiya clear. Then go back to your tried-and-true Future floor wax!

Gunze has a great mild clearcoat in a spray can called Mr. Topcote, I think the stock # is B-501. You can get it from Hobbylink Japan. It goes on like Future, dries in minutes, and has an ultra-slick, almost Teflon feel about it. It goes on smoother than TS clear. It also polishes out nicely.

[p9o1r1sche]

I thinned it to about 2/3 paint, 1/3 denatured alcohol. Putting it on thick is one problem because I got a few areas where the clearcoat collected into pools.

I have a dehydrator. Maybe I'll give that a try. Bob, youre right about the decals being the reason I havent stripped it. Right after I sprayed this thing I thought - why didnt I just use the TS clear?

Well, another lesson learned.

[Vric]

Good thing to know. I was about to try the same thing soon. Might get some TS clear after all

[lotus_man]

I find their bottle acrylics too soft for a top coat. The synthetic laquers in their cans dry fine, but the acrylics are too soft even after months of curing time.

[proosen]

After about one year I pulled out a Scania truck finished with Tamiya acrylics. Guess what? As soon as I started to polish it it went soft and I got fingerprints in it...sigh!? You have to take care using the right product on these acrylics, as some products contain solvents that will attac the paint and make it soft again, no curing time in the world can fix that. If you use Tamiyas own rubbing compound there shouldn't be any bad reactions, at least I haven't had any. The main problem as far as I'm concerned is that the acrylics is crap for bodyworks. Yes, I know there is people out there that make fantastic paint jobs with it, I'm just not one of those. At this point I've quite trying and use enamels and laquers instead, the things I'm used to and knows how they work. I would really like to manage to paint with acrylics but I also want to finish a model every ones in a while.

Niclas

[MPWR]

Wow. I don't know what I'm doing different, but I've had terrific experiences with X22- much better luck than I've had with TS clear (I've had it go on well, and then crack several moths later!). I can only guess that maybe you're spraying it on too thick? I've been able to polish out Tamiya clear consistantly after two days. I used to use Future for clearcoating, but I've had too much trouble with it drying inconsistently and crazing- switching to Tamiya clear solved that.

Wish I could tell you more. I thin with isopropyl alcohol cut with water, and I add this to the clear (or other acrylics) drop by drop until it sprays well.

Good luck!

[ZoomZoomMX-5]

Originally Posted by MPWR

Wow. I don't know what I'm doing different, but I've had terrific experiences with X22- much better luck than I've had with TS clear (I've had it go on well, and then crack several moths later!). I can only guess that maybe you're spraying it on too thick? I've been able to polish out Tamiya clear consistantly after two days. I used to use Future for clearcoating, but I've had too much trouble with it drying inconsistently and crazing- switching to Tamiya clear solved that.

Wish I could tell you more. I thin with isopropyl alcohol cut with water, and I add this to the clear (or other acrylics) drop by drop until it sprays well.

Good luck!

The reason your TS clear cracked is because you have to apply it at a particular time in the drying cycle of the paint below it. The clear dries at a different rate, so if it's applied at the wrong time, it may very well crack after some amount of time, usually not immediately.

TS clear will not crack if you apply it to fresh TS paint in under one hour (mine is usually applied in 10 minutes or so after the color). Otherwise the base paint must dry for a month to fully cure before applying the clear.

[minniebanister]

Originally Posted by MPWR

Wow. I don't know what I'm doing different, but I've had terrific experiences with X22
...
I've been able to polish out Tamiya clear consistantly after two days.
...
Wish I could tell you more. I thin with isopropyl alcohol cut with water, and I add this to the clear (or other acrylics) drop by drop until it sprays well.

Hmmm? It sounds like you do exactly what I do except I thin much more than you do and my paint stays soft "forever". I will experiement with less thinner and see what happens.

What ratio do you use when "cutting" your IPA? And do you buy 100% IPA or is it already diluted somewhat (e.g. 70% or 90%)

[MPWR]

Originally Posted by minniebanister

Hmmm? It sounds like you do exactly what I do except I thin much more than you do and my paint stays soft "forever". I will experiement with less thinner and see what happens.

What ratio do you use when "cutting" your IPA? And do you buy 100% IPA or is it already diluted somewhat (e.g. 70% or 90%)

I mix up a batch of thinning solution, using 70% isop (supercheap!), and about 2:1 water/iso. I mix this in a dropper bottle, and add it as necissary to the X22 (or other acrylic) in the paint cup.

Maybe spraying light layers makes the difference. I don't generally spray 'wet' coats- just enough to see that there is clear sprayed on the surface I'm painting. It tends to be very self leveling if left to itself. I spray 5-10 coats, leaving a half hour or more between coats, often over a couple of days. I usually find that I can spray 3 or 4 layers one evening, and the next morning rub out any obvious dust, and then spray on a few more- repeat as necissary. I like to leave a week after spraying before polishing, but to be honest, I'm rarely that patient- as I said, a couple of days seems to be all it takes. Can't say it's rock hard, but it's solid enough to polish.

I hope this helps- I don't know if there's enough difference between what I've dscribed and what you've tried to make a difference- but, I certainly have had it work for me, and consistently enough that it is my clear of choice.