Help: Spraying Clear Gloss

A "Rough" and/or "eggshell-like" appearance is quite common when applying a gloss coat over flat paint. You just need to keep applying more coats until it smooths out.

1: There are no heavy pigments in a clear gloss to settle, but I would stir it anyway

2: Gunze's paints (and I'm generalising a bit here) are almost thin enough to spray straight out of the bottle, but I would add some thinner to reduce the risk of "orange peeling". I'm probably not the best person to give thinning ratios - I tend to go very thin myself (eg 2 parts thinner or more to 1 part paint) but that's just me - it suits the way I paint.

3: How many coats? - As many as it takes to get the level of gloss you want. (sorry - not very helpful am I?) This will vary depending on how thin you mix your clear coat and your individual painting style (eg. do you get up close and personal or do you "nuke it from orbit"?). I would suggest many light coats, gradually building the required level of gloss, rather than one or two heavy coats.

NOTE: It's very difficult to see just how much you're applying when laying down clear coats. Unlike "solid" colours, you have very few points of reference to see what's been covered and what hasn't, and you don't want it pooling, running or filling in the panel lines you're going to highlight. Take it slow, and paint under a bright worklight.

A rough surface after spraying is usually indicative of one of three things.

1)  The paint is partially drying in the air between the airbrush and the surface.  Common if the paint is acrylic.  Reduce the distance between the airbrush and the surface (which normally requires a lower pressure) or add som acrylic retarder to your paint cup.

2)  The coat is too light and not providing enough paint volume for it to level out properly.  I see that a lot spraying Future.  Future needs to be sprayed somewhat "Wet".

3)  The underlying paint is flat as opposed to gloss.  In this case the clear has to fill in the texture of the flat paint before it can level out properly.  Again, a slightly heavier coat will help in this case.

I agree with Phil_H in that I seldom find the need to thin any clear, be it flat or gloss.  They are usually  thin enough right from the container.  I've never use Gunze though so that may be different.

I also never spray at 20 psi.  I prefer to spray at lower pressures and get in much closer to the surface.  I normally use about 12 psi and have seldom found the need to go above 15 psi.

Thanks for the tips everyone.

Scott: The reason i use a high pressure is because i read in an article to get a smooth base coat, it is better to blast it on from a distance.  I'll lower the pressure and get in a bit closer to see how i go.

Karl: I haven't seen Future in Australia, however, there is a similar product called Pledge One Go and am currently experimenting with that too.

cml

It's been quite a while since I last used Gunze clear, so I don't exactly remember the ratio I thinned it at- but I do remember using quite a few coats to get a smooth, shiney surface.  One warning when using it-

Give it PLENTY of time to dry, like two weeks if you can.  If it's not completely cured, the fumes coming up from the still-drying gloss can interfere with the later flat coats.  I did this on my 1/48 Zero and ended up having to completely strip it back down to bare plastic and start over.  Here's a photo of the disaster:

Daywalker - thanks for the tip, i've noticed it seems to take a while to dry, didn't realise it would take that long.

Just to follow up on this link:

I experimented last night spraying the Clear Gloss with a much lower ratio 4:1, and lower air pressure, 10 psi.

I found that the Gunze Sangyo clear gloss is way to thick at this ratio, and it sprayed on horribly - not at all smooth and even.  I think i'll go back to thinning it around 60:40, and then vary the air pressure.  Given glosses need be thinned more than matts, i can only assume this is true for the clear gloss.

Also, i've been experimenting with Pledge One Go (similar to Future), i seem to have better results with this.  It does require a little bit if practice though, as it is much much thinner than the paint - it does pool or run if the air pressure is too high.

My only concern is the Pledge has a yellow tinge to it (in large volumes), you can't notice it in a small jar, but certainly it looks yellow in it's bottle.  I hope it doesn't interfere with light colours.

cml