Mist coats...grrrrrrr

[Skii]

So many times I see peeps on this forum producing glorious results by 'misting' paint onto their bodyshells, but time and again this technique completely fails to work for me.

I have a gravity fed Iwata style airbrush, using a small compressor, I use Zero paints unthinned yet any attempt at a mist coat results in a rough paint texture that feels like coarse sandpaper, thus needing a good rub with wet n' dry or micromesh cloths, obviously this isn't ideal.

Can anyone give me any obvious pointers as to what I'm doing wrong?

thanks


John

[MPWR]

Yes- you must thin the paint.

For optimal results spraying lacquer (or other paint) in mist coats, you need the paint as thin as possible, and the pressure as low as possible.

If the paint is properly thinned (and Zero paints can take a terrific amount of thinner!), the paint is very fluid when it strikes the surface and it flows together. You need to apply this superthinned paint in mistcoats because if you apply it any more heavily it will run.

If the paint isn't thinned, it will partially dry in the paint stream, leaving a bumpy texture as paint droplets accumulate.

For best results, use only the manufacturer recommended thinner/reducer. Anything else (especially cheap hardware store generic lacquer thinner) is a crap shoot.

[Skii]

Originally Posted by MPWR

Yes- you must thin the paint.

For optimal results spraying lacquer (or other paint) in mist coats, you need the paint as thin as possible, and the pressure as low as possible.

If the paint is properly thinned (and Zero paints can take a terrific amount of thinner!), the paint is very fluid when it strikes the surface and it flows together. You need to apply this superthinned paint in mistcoats because if you apply it any more heavily it will run.

If the paint isn't thinned, it will partially dry in the paint stream, leaving a bumpy texture as paint droplets accumulate.

For best results, use only the manufacturer recommended thinner/reducer. Anything else (especially cheap hardware store generic lacquer thinner) is a crap shoot.

Thanks MPWR

I suspected the paint wasn't 'wet' enough, I think you've confirmed it, I'm assuming Isopropyl alcohol would be ok for thinning Zero paints as it does a pretty good job of clearing up?

I'll give this a go tonight again

thanks


John

[MPWR]

Originally Posted by Skii

I'm assuming Isopropyl alcohol would be ok for thinning Zero paints as it does a pretty good job of clearing up?

NO!!!

Definitely not. There is a real difference between something that works well for cleanup vs a suitable thinner. You can clean your airbrush with petrol also, but that doesn't mean you want to thin with it. (Don't try that, either. It's like stripping paint in brake fluid, or drinking Budweiser- just because a substance might destroy paint/get you drunk does not mean that it's a good choice for the task.)

Alcohol is not compatible as a thinner with cellulose lacquers. Get a can of this stuff.



If you're in the EU/UK, you can get it straight from a Lecher's auto paint dealer (I think I spelled that right?) It certainly won't be called Zero Paint, but ask for Lecher's basecoat reducer, and if they have both slow or fast dry formula, get the slow.

If you've had good luck cleaning up with isopropyl, great- no need to use anything more expensive/exotic. But for thinning, use the proper stuff. It's much more expensive sure, but a litre can will last you years, and the results are completely worth the 'investment'.

[Skii]

Hi MPWR


WOAAAHHHH

thanks for this, appreciate the advice !

This is the stuff I'm using

http://www.hiroboy.com/catalog/produ...oducts_id=1440



although it claims to be pre-thinned I guess this would be the correct stuff to thin it more....?

[MPWR]

Happy to help.

"Pre-thinned for airbrush use" is rather meaningless. Generally it means only that the paint in question can be pushed through an airbrush. But for optimal results, you will want to thin it further for yourself. Since Steve packs his paints in plastic containers, the volatiles in it are outgassing though the bottles as soon as they are filled. So these missing solvents must be replaced by adding suitable reducer. Thinning by ratio is a poor practice (especially as we know that Zero Paints have almost by definition varying solvent levels), but I would start with 1/1 or even 2/1 thinner/paint.

I expect that that's the thinner intended to go with Steve's clearcoat- although as I haven't used his clearcoat I can't say for certain (as I'm on this side of the pond, I use PPG's clear and reducer). If there was a good way of reaching Steve I'd ask him, but failing that the cellulose thinner is my bet for thinning his clearcoat.

[cyberkid]

Hope I'm not thread hogging but:
@MPWR About how much do you thin the zero paints for misting? Like a rough ratio?
I need to do some patch up work and misting seems like the only option.

[MPWR]

Originally Posted by cyberkid

@MPWR About how much do you thin the zero paints for misting? Like a rough ratio?

Covered that just above. But again Zero Paints are a moving target, so your mileage will vary.

[Zubski]

Originally Posted by MPWR

but I would start with 1/1 or even 2/1 thinner/paint.

How exactly do you do this?

[MPWR]

I put an amount of paint in my airbrush's cup with an eyedropper, and then I add that same amount (or twice that amount) of thinner to it with another eyedropper.

If the paint appears thick, I'll add more thinner to start with (2/1 instead of 1/1). But the only way to really tell how much thinner it needs is to spray it and watch how it behaves. If it doesn't flow, it can take more thinner. If it threatens to pool or run, there's too much thinner. I thin until just before the paint pools/runs, and then I control the running by how heavily I'm applying the paint (heavy mist coats vs light mist coats).

[sileightsix]

MPWR,

You have great info. and I'm grateful that you share.

Always inspiring to read.

[Skii]

Originally Posted by sileightsix

MPWR,

You have great info. and I'm grateful that you share.

Always inspiring to read.

seconded.

[Sixx]

Originally Posted by sileightsix

MPWR,

You have great info. and I'm grateful that you share.

Always inspiring to read.

I agree, I've learned a great deal from so many of modelers here and MPWR is one hell of a good teacher. His work speaks for itself!

[360spider]

Great advice Andy.