Hi Rusty,
I understand your frustration ( I used to paint transit buses)
First, make certain that your paint is stirred thoroughly, just as we do with automotive paints.
From your description, It sounds as if your paint needs more thinning. With Polyscale, an unwritten rule of thumb is to thin it an additional 15% to 20% with Distilled Water. For me it has worked quite well. The paint lays on smoothly and still provides good hideout. This was suggested by my LHS's owner, Kevin, who is a very talented airbrush painter.
If you try Badger Modelflex, no thinning is required. Stir, pour into your airbrush jar and spray.
Give it a shot and let us know your results. Test your mixes on some scrap plastic or junker freight car shells.
Let us know your results
"I like my Pullman Standards & Budds in Stainless Steel flavors, thank you!"
If you have a larger tip for your gun, try that. I was having trouble with my guns (pache and badger) when spraying polyscale acrylics. When I switched to the larger tips and upped my line pressure to around 40PSI all of my problems went away. In fact I hardly thin the paints anymore and get good results. I do thin the better covering colors, gray, blue, red etc. I have found though that thining the yellows and whites can cause headaches when trying to get the coverage needed.
Dan Pikulski
www.DansResinCasting.com
To restate the obvious, Strain the paint!!!
The oriface in an airbrush that is suitable for delicate work, is very small and can get plugged with small particles of grunge that is present in even the best paints.
73
Bruce in the Peg
As best I can tell, inducing frustration is what airbrushes are supposed to do, aren't they??
Years ago I had a couple of expensive double-action / internal mix airbrushes that I used for painting with thinner based paints like Floquil. Once acrylic RR paint came along I switched to them, largely for safety issues, and found the airbrushes gummed up and became unusuable junk very quickly. I finally gave up and got a $15 external-mix Testor's airbrush and found that worked fine with the acrylics. Ya the results aren't quite as good as with my old $95 airbrushes, but the external mix ones are easy to clean...acrylics just dry so fast that by the time you go to clean the internal mix brush out, the paint's already turned to silly putty inside the airbrush.
As stated, larger tip, higher pressure and absolutely strain your paint!
Where do you work that you get to paint 1:1 scale stuff?
Don't get frustrated, after doing some reading; I think the problem is the amount of thinning. I have been having the same problem. I will soon be doing a lot of painting and plan to increase thinning up to 40-50% and see if that takes care of the problem. Also someone mention using lower pressure 8-10 psi instead of 18-20psi.
In the end, it is probably not your brush.
Peter
I agree with all of the above. I don't use an airbrush, never have...but bear with me here...I have done lots of reading about them and the problems encountered when their users post here looking for help. The airbrush models have all mostly been around for a long time...paints, too. So, they do work, and for the vast majority of users. But, like anything else in the hobby, you have to have a multi-disciplinary approach to it. Merely point and shoot doesn't exist in the hobby...not even with decoder-equipped locos. There are things you must learn and carry out in order to get good performance. Paints do have to be well mixed, and if their mixing raises somewhat larger clumps that don't get broken down by the mixing process, where will they be found? In the bottle neck of the instrument, which is likely to be the final aperture. So, not only do you have to mix, but you have to strain, and then thin until the device actually makes you smile as you use it.
-Crandell
While I much prefer lacquer-based paints in my double action, internal mix Paasche VL, I have found that lowering the air pressure worked for me to overcome the clogging problem with acrylics. As for Badger paints, I've not used them in my airbrush. I bought one colour for brush-painting the raised numerals on my CNR steam loco cabs, and while the colour and coverage are excellent, the paint dries too quickly - I literally have to clean the brush after every brushload.
I've also found that some acrylics thin well with distilled water, while others work better when thinned with methyl hydrate.
Wayne
I've been custom painting for a living for 20+ years and using acrylic paints almost exclusively for 10 years. I use both external and internal airbrushes with equal results and they never gum up. They do get clogged from time to time when I forget to strain the paint. Never paint from the bottle the paint came in, use a clean one, I actually never paint from bottles, I always use a paint cup, (less to clean).
here's some basic rules:
1. Thin all paints to the consistency of 2% milk. Even Modelflex.
2. Stir well. The pigments settle to the bottom, shaking won't fully re-incorporate the pigments with the carrier. You can shake after you've stirred well as long as you follow step #3.
3. Always strain the paint before using. Dried paint particles at the top of the bottle fall into the paint every time you open the bottle. This happens with solvent paints as well, but the solvent will redisolve the particles, with acrylics, once dried they're dried forever. So, again, ALWAYS strain the paint, I use hand-me-down nylon stockings. My airbrushes rarely get clogged. There are no shortcuts here.
4. A #3 or medium tip is what is recommended for acrylic paints if properly thinned. Here's where practice is invaluable: adjusting paint versus air flow and distance. Distance from surface should be about 7 or 8 inches. Start at about 20 psi and adjust the paint flow until you get a nice mist without spatters. If you are getting spatters, back off the paint flow or increase the air pressure, you should aim for 20-30% coverage per pass. Practice until you get a "feel" for this. Max psi should be 30, if it takes more, the paint needs to be thinned more.
5. With acrylics, dry paint will inevitably build up at the tip. I use one of those steel wire brushes you can pick up at the dollar store to give the tip a little scrub when the build up starts to impair the flow. Quick and simple.
6. Clean airbrush imediately after you're done. Don't use solvents or amonia, these can cause acrylics to gum up if there is any residue left in the brush. Use pipe cleaners or better yet pick up a set of bristle brushes (for airbrushes) from an auto body paint supplier (like PPG). Use water (or with some detergent) to clean. If paint has dried in your equipment, you can soak the parts in laquer thinner of brake fluid, then clean with soap and water and rinse very thoroughly.
Practice, practice, practice. And have fun!
Jay
C-415 Build: https://imageshack.com/a/tShC/1
Other builds: https://imageshack.com/my/albums
Doc, I have read that others use Windex. Any comments?
Is your paint old?
And I don't just mean how long you've had it.
How long has it sat on the store shelf?
Never hurts to ask.
If they don't know, don't buy.
Craig
DMW
modelmaker51 wrote:5. With acrylics, dry paint will inevitably build up at the tip. I use one of those steel wire brushes you can pick up at the dollar store to give the tip a little scrub when the build up starts to impair the flow. Quick and simple.
I have used a qtip or trimmed acid brush dipped in an 80/20 water/alch solution. The idea of using steel wire on my tip scares me a bit..
Chris
4x8 are fun too!!! RussellRail
selector wrote:Doc, I have read that others use Windex. Any comments?-Crandell
I've read of that, too, but have not tried it. As I use methyl hydrate as a paint stripper, I have it on hand - it's also cheaper than Windex or windshield washer fluid.
True enough, Wayne. And we both know it is great for taking care of acne, dermatitis, folliculitis, tooth decay, warts, and a host of other ills and conditions. It is also great for the plumbing when a teaspoon of it is added to one's cereal most days.
Regards, and thanks for your reply.
Actually, methyl hydrate does require careful handling, even though it's readily available at paint and hardware stores, and home improvement centres. It's extremely volatile, and with an only slightly noticeable odour, can fill a room with vapours pretty quickly. The fumes are readily absorbed by the eyes (as are many hazardous vapours) and the liquid easily absorbed through the skin, causing nerve damage and, eventually, liver and kidney damage. I don't mean to sound alarmist, but it should be handled with all appropriate precautions.
cwclark wrote: I use floquil paints most of the time (and they aren't phasing them out) but my next choice is poly S paint diluted with distilled water. I would suggest that you stir your paint well before use. Check out micro-mark and look for the small screen strainers to filter the paint before use. Chances are you are picking up dry paint particles as mentioned and is clogging the airbrush ports. The reason you don't shake the paint is that the particles dry to the top of the lid and fall into the paint when it's shaken again. Always stir your paint and stir it well. There are a lot of pigments in paint and they need to be blended into the paint thoroughly....chuck
As far as stirring the paint, I picked up one of the battery operated paint stirrers from Micro-Mark, and it works like a dream. Just make sure it's completely stopped before you take it out of the bottle.
Marlon
See pictures of the Clinton-Golden Valley RR
I use a Badger single action internal mix airbrush, mostly with PolyScale paints. I thin by eye around 1/3 or slightly more. with PolyScale thinner. I've never tried distilled water or Windex, although I've read that they work. The lighter colors (white, yellow and grey are heavier pigments) and I have had difficulties with these clogging up the air brush.
When I spray, I always use a Badger inlet screen and the only times I've had paint particles collected on it were with older bottles of the lighter colors. Now, I pour out what paint I need into a small mixing cup and close up the bottle immediately. BTW, I use small pieces of Saran Wrap over the mouth of the bottle to seal the bottle to the cap. Prevents having to use a pair of pliers to open it the next time.
I had an experience similar to yours recently trying to spray an older bottle of refer white. I finally gave up and screwed on a bottle of old Modelflex white (unthinned - never have needed to thin them) and it worked perfectly. My conclusion - I had an old bottle of paint that I threw out.
As to air pressure, I almost always spray between 15-18 psi, except when weathering; then I use 4-8 psi. Works beautifully.