new guy

[bonsaijimmy]

Hi All

I have recently re started my model making hobby once more. So, i invested in a beginners compressor and air brush set up(timbertech). I've never use an airbrush, but i thought id give it a go. I've made a few 1/72nd scale kits, and im happy with the results when i get everything working correctly.But this is where im running into problems, and i would love some feedback from the more experienced modelers. So, if i may, i will list my concerns and questions. I make my model kits in an outside garage, which as you can imagine can be cold, i do have heating in there, but i only use it when im building or painting kit.

 

1. After running the small compressor for a while, i am getting water in the line. I clean out and dry the filter on the outlet of the compressor, and i will swap hoses over and hang the other one up in side where its warm. Does the water problem occur because of the cold temp in the garage?

2.I am using Vallejo paints. I keep the ones i need to use in a small heated cabinet, so they are quite runny when i use them. But, i have thinners, and flow improver, should i mix the paint with the additives?I have added small mixer balls to the paint bottle as well to help with agitation.

3. When spraying, what should be my ideal pressure and needle size?. I have swapped out the 0.2 needle and fitted the 0.3 needle and appropriate nozzle, im using a pressure of about 2.5bar.

4. Should i prime my kit before painting?The reason i ask, is i attempted to use Vallejo gloss white, and it turned out to be a pain in the A$£E!!. I was building the Tamiya A10 kit, which is a dark green plastic. Coverage was awful, and with other issues as listed above, i was going round in circles. I have a 1/48 Vulcan to build, and i dont want to start that until i get things settled as regards paint and equipment.

5. My birthday is coming up, should i look at a new airbrush? or compressor or both?

 

Thankyou for taking the time in reading my questions. I will post some pics of my first attempts when i can.

[samourai47]

I've been airbrushing for about a year now so still pretty new. Hope this helps

 

1. You should have a watertrap on the compressor, if so then as long as its not coming through the hose into the brush then it's fine. Just empty the trap every so often 

2. Ratios with vallejo paints are all up for interpretation, personally I've been using a .4 needle with vallejo air paints, it sprays neat at 20psi but I tend to thin it down slightly 1:4 thinner to paint. 

Don't pre-mix the paint, apparently it can go funky so best to just mix before you spray. I used flow improver in the past but found it didn't go much for me. 

3. Same as above really, depends on scale, and what you're doing. I have a cheap brush with a 0.5 set that I use for priming and then a different brush with 0.4 for everything else. 

If I needed to do detail then I can switch to 0. 2. 

4. I prime exterior but not interior, I find if you don't prime then the paint doesn't stick as nicely and can cause the issues as you've mentioned

I would avoid the Vallejo primer and get some MIG oneshot if you're sticking to water based Arcylics like me. The Vallejo doesn't sand well and I've found has rubbed off at times. 

5. As long as the compressor works I don't think it's worth it to change, possibly the airbrush if you're comfortable. I practiced for a few months on a generic brush from Bartsharp before getting a H&s evo 

 

Edited February 18, 2022 by samourai47

[Mark Harmsworth]

7 hours ago, bonsaijimmy said:

Should i prime my kit before painting?The reason i ask, is i attempted to use Vallejo gloss white,

Certain colours are tricky to get an even finish (like yellow and red) and are an extra reason to prime - in addition to better adhesion. I would definitely include white in that and I always use a white primer for a white finish.

Mark

 

[Tijuana Taxi]

Try an inline moisture filter like a Sparmax Silver Bullet.

 

 

[fishplanebeer]

I have an Iwata Eclipse airbrush and use the 0.5mm nozzle for most work at a psi of around 14-16 which seems to work quite well, plus I have the 0.35mm nozzle if I want to do really detailed stuff.

 

The pressure and paint thinning is a matter of trial and error as it can/will vary between different paints and pigments but for me a ratio of 70:30 paint to thinner works well with all the enamels I use plus Tamiya acrylics as well. With varnishes I tend to go for a 60:40 ration of varnish to thinner in order to apply a thin-ish coat.

 

As for priming I now use the Tamiya grey primer in the aerosol as it provides a good basis for the paint to grip, shows up any defects in my build and is pretty much essential when spraying lighter colours such as yellow and white.

 

Some compressors will only deliver a maximum psi of around 18 with a 0.5 or 0.35mm nozzle so if yours is similar then you will need to thin the paint down to at least 70:30 to get good atomisation and smooth coverage.

 

Regarding temperature I never spray when the air temperature is low, as in below 10 degrees, as this prevents correct atomisation and you can end up with a rough and uneven finish. Plus I wouldn't warm your paints up before using as they will work absolutely fine at room temperature and warming them up just makes them artificially runny and more difficult to then judge the correct consistency as they will inevitably begin to cool down and thicken once removed from their heated cabinet.

 

HTH.

 

Regards

Colin.