Airbrushing Humbrol acrylics, what went wrong?

[Guest]

Having got a frreebee kit from Modelzone a MKIIa Spitfire with the little pots of acrylic paint I thought it would be an idealtime to have a bash at using the acrylics and the airbrush. All I managed to do was continually clog the nozzle. It didn't seem to matter how much I thinned the paint or raised the pressure I would get about 10-15 secs of spraying time and then it would clog. At one stage it was coming out in little pulses. . My guess is that I didn't thin it enough but to me it seemed like water. I also tried pressures from 10psi to 45psi.

Any hints and suggestions please.

[Guest]

Barry a number of things.

Humbrol Acrylics are marketed for hand brushing & airbrushing. So a lot of thinning with is needed for air brushing. The norm seems to be about the consistency of milk.

I use normally a .4 needle/nozzle & some use a .2 needle/nozzle. Less than .2 & I think you will loose it altogether.

No doubt you have taken the brush apart & given it a good clean. But have you given the nozzle a good clean. It could be a partial blockage in the nozzle which is then clogged up all together when you air brush. You really need a reamer to ensure the nozzle is perfectly clear. I tell by sighting down it against a white surface. You can then see if you have a good clean hole at the end. Careful if you use a reamer as the nozzle is very fragile & over use of the reamer can damage it easily.

Another that may be a problem. How old is the kit. The paints may be oldish & have clogged with bits in the paint. Pour an amount on a piece of paper & see if it is clear of little lumps.

I normally airbrush at about 18 which seems average some below some above.

Any way that is a start.

Laurie

[Guest]

I don't think it would matter how thin and what pressure you used.

those little pots of paint are only really suitable for brushing from what I've read. they've also probably been on the model box for a length of time and have either started to go off or are beyond help due to seperation in the little pots. I don't think how ever much you mixed them they would be ok.

just my opinion

[AlanG]

I've never got on with Humbrol acrylics. Always had problems with them. This is why i use other makes now.

[Guest]

Many thanks for all the replies I will try them all. I will also try some Tamiya acrylic I have found in my paint store to compare the Humbrol against.

[Guest]

I once bought one of those kits, a Hurricane, see my gallery, and I diluted the small pots with a lot of Tamiya thinner about 70/30 thinner to paint and it worked fine through a 0.5mm nozzel Iwata Airbrush. I wouldn't want to do it again mind; your Tamiya with 50% Tamiya thinner is much more reliable. Cheers Derek

[BarryW]

Barry - I would suggest Vallejo Air acrylics for the airbrush, the ones with the black tops.

A lot of people like Tamiya but, specially for beginners, Vallejo are easier to use as the Air brand come ready for the airbrush and can be applied into the airbrush bowl from eyedropper bottles the paint comes in. I find them great and junked my Humbrols for them.

Vallejo Model Paints - Model Air

[Guest]

Thanks, the Vallejo Air acrylics sound good and not a bad price either. I'm trying to get away from enamels as I have to go outside to spray which is dependant on the weather and I find the fumes give me a headache after a while. In comparison acrylics seem ok indoors with reasonable ventilation and seem to give off no fumes or smell I don't get a headache either.

[BarryW]

Barry - while acrylics are certainly better than enamels in respect of fumes and are less toxic, you should still wear a respirator when airbrushing.

[Guest]

Thanks for all the info, I do usually wear a mask when spraying, well with the enamels anyway so will continue when I try the acrylics. again thanks

Barry