Trying to change over to acrylics, with problems

[Guest]

I am trying to change over to acrylics as just lately even with mask and lots of ventilation I am getting stonking headaches with enamels (Revell and own brand thinner). Now Model zone have gone I am restricted to Hobbycraft and Humbrol locally (Their selection of Revell Aqua is very poor). I have been trying to spray the Humbrol acrylic metal colours with little success. Thinning it in the ratio Humbrol suggest results in a brief spurt of colour and then nothing. Thinning it so it will spray leaves it virtually colourless. I have taken the airbrush to bits and cleaned and checked everything and its all clean. I have checked the nozzle and can just get a 0.3mm drill though it. Do I need a bigger nozzle? I am using the Humbrol thinners and have also tried water with the same results, and pressures from15 to 30psi.

Another strange thing, The little I have managed to get onto the model has gone on and then bubbled up on the surface, looking like stove enameling, despite being washed down and primed with acrylic primer before hand. Having left it to dry I went to rub it back and found it had dried perfectly flat with no trace of bubbling, is this normal?

[BarryW]

Barry.

I use Vallejo Model Air (John at SMS supplies it) and it has the following advantages:

1/ It is already mixed for the airbrush though for smaller needles and/or lower air pressure you may want to think it a little. I use Vallejo Airbrush thinner for this.

2/ They come in eye dropper bottles that are easy to dispense into the airbrush cup and when you knock the paint bottle over, no spills....

3/ They have an excellent colour range.

http://www.scalemodelshop.co.uk/acrylic-paints/vallejo-paints.html#cat=vallejo-modelair

http://www.acrylicosvallejo.com/en_US/model-air/family/17

I spray Vallejo Model Air mostly through a 0.2 needle using a H&S airbrush at about 25psi. I will sometimes thin it usually about 10% in hot weather or more of course when pre or post shading.

Vallejo varnish though is best sprayed through a 0.4 needle.

I hope that helps.

I started with Humbrol myself but had the same problems you are having, I tried Vallejo and immediately after gave my remaining Humbrol away and bought in Vallejo, it was a revelation.

[Ian M]

What are you thinning it with may I ask.

Total Vallejo user here as well but I use the Model Color range. This to has to be thinned for spraying but has never given problems...

Ian M

[Guest]

Barry, thanks for the info, I must admit I wouldn't have gone for Humbrol as I prefer the Revell but being impatient I bought what was available. I will try the Vallejo on the next model.

Ian, I thinned it with Humbrol Acrylic thinners and then I tried it with water and as a last resort with Future. I had bought three colours, Silver, Aluminum and silver Chrome. The Silver seemed very watery even after stirring it for ages. The Aluminum need a shovel to dig the pigment about it was very thick and gloopy. The Silver Chrome seemed just right but none of them would spray properly no matter what percentage thinners I used. So for the moment have resorted back to the brush and I must say that they seem to brush very well.

[yak face]

I havent had any experience trying to spray the metallic colours but I did have a nightmare trying to spray the normal colours on my tomahawk, although I didnt use Humbrol thinners , as I didnt have any I tried Vallejo airbrush thinner. The end result though, was very similar to your experience , the brush spluttering and only seeming to spray the thinners - as if the paint pigment was too big to get through the nozzle (mine was a 0.3 nozzle too) I dont know if this is due to incompatibility of the thinners or what .However I found like yourself that they brushed very nicely though. Maybe you could try Vallejo , or Tamiya , these both give me no trouble at all when used with their own thinners , although I appreciate you would have to get them mail order (Scale models shop is a good place to start!) cheers tony

[The Migrant]

Metallic acrylics are notoriously hard to airbrush, because the metallic particles in the pigment tend to be quite coarse. I've never used Humbrol acrylics but have had reasonable results with Tamiya and Citadel, thinned with Tamiya regular acrylic thinners. They're nothing like as smooth as Alclad or enamel metallics, though.

[tanktrack]

for my 2 pence worth if you are thinning acrylics put the thinner in first then the paint so that the thinners is at the bottom of the cup before the paint so as not to have a thick glup of paint when you first spray then take an old soft hairy stick and mix them in the bowl and do a test spray , I find this is my best way to mix none Vallejo air paints prior to spraying , im using the smaller needle for the iwata and this works , also if you find that not a lot is coming out then put the cup lid on and a tissue over the nozzle and give the air trigger a few squeezes and the cup should bubble up and free any blockages BUT remember the cup cover or you could end pebbledashed in paint . good luck

[downscale model art]

i agree with mike on this one. the particles in metallics , particulary humbrol are too large to get through the nozzle. the only thing getting through would be mostly coloured thinner. this might explain why it blistered on the model and then settled down as the thinner evaporated

[Guest]

Many thanks for all your input. I have been having a play and find that the non metallic acrylics are spraying ok so it must be just the metallics as suggested that are the problem. Next time I will try with an old non gravity airbrush I've got kicking around as it has a lot bigger nozzle.

[Guest]

tamiya metallics are the only ones that i have had sucess with spraying,never get a problem with these but revell and humbrol are the same for me, they just clump up in the bottom of the colour cup.