Splatter Splatter!

OK guys. Usually when I weather a car/motive power…I prep it with a bit of flat gull grey mixed with testors thinner. Well I’ve been busy lately, and have just gotten back into it. The other day I attempted to weather a nice maroon colored whip chip gon. Well, the paint out of the brush (20 PSI, regular tip 3/1 paint mix as described). It looked like a Jackson Pollack! I tossed it up to being rusty, and cleaned it up and it turned out okay at best (it looks fine in a through freight, can’t hardly tell unless you look reeeeal close). Well tonight IO needed to weather my two new NS diesels for an up coming show. I mixed the usual, and same stuff. So I tried mixing some poly scale gray with water, and 70% iso, with the same results for both. Splatter splatter. Is my paint old, or did I lose my touch? Thanks guys.

Kyle

Sounds like a dirty airbrush? Did you take it apart and clean each individual pieces thoroughly? Let it soak overniight?

I did! I even used a new airbrush (bday money). Then just a few moments ago I tried to dullcote said locomotives, and it resulted in gray-like splatter everywhere. I wiped everything off with thinner (plastic/decal safe it appears). Removed the paint, but sort of left the paint chalky looking. Did I just ruin to locomotives, or is some soap/warm water tomorrow when my nerves are cooled going to make it better? WTH Goose!

this is why you always test paint some piece of scrap plastic or whatever right before you turn the spray loose on your treasured model. not to lecture you but i learned the hard way. i know this does not answer your question but i thought it was worth mentioning for the benefit of others who might see this post.

grizlump

what’s about the pressure?

which brand of dull cote do you use?

Wolfgang

I get that result with 2 things. I have a double action brush, and if I try applying paint before I have air flowing it spits and also when I have a goober in the needle. I also use a little more air pressure than you, mine being at 35psi. I have since tried making it a practice to get air flowing before the brush is pointed at the model. On another note, make sure the paint is mixed well BEFORE putting it in the cup. My brush has a channel for the paint to go through to enter the brush and if I were to put paint in the cup and then thinner, there would be unthinned paint in that channel. I also thin my paint more than the bottle says. I find it gives a much flatter finish without obscuring any details.

Kyle, you could be encountering any one of a number of possible problems that will results in paint spattering and quite honestly attempting to diagnose such problems from a distance can be difficult. The following are some common causes of paint spattering.

As others have said, a partial very small blockage in the needle could be the culpirt. Another highly likely possibility is high humidity (do you have a moisture trap?). Then there is too low an air pressure; you indicate 20psi, while 30-35psi would likely give better results with acrylics. Also quite possible is too much surface tension in the thinned paint (what are you using as a thinner?), calling for a flow enhancing product to be added to it.

CNJ831

Also, make sure the pressure gauge is accurate and working, I have seen inaccurate ones before.

Remove the nozzle from the air brush and sight through it against a white surface - a piece of paper should do. The hole should appear round. You may have to blow through it to clear any moisture. If it does not look round, soak the nozzle in solvent; you mentioned acrylic paint so use 90% rubbing alochol and check again.

Another question is how long have you been using this nozzle? I find mine wear, and I need to replace them about once a year. A bad spray pattern from a clean nozzle can be dure to a worn out nozzle.

Since you’ve cleaned the brush and tried a second one with similar results, I lean toward the high humidity theory. Second would be low pressure.

Just two guesses from afar.

Well the good news Is that I got my ponies clean. There appears to be no lasting damage after about 3 hours of thinner/alcohol to get all the dullcote and paint off. That is the good news. Through trial and some tribulation, I almost discovered a new weathering technique. The wiping with the thinner left the surface flat, and perfect for the powders I was applying. That being said, I can’t say that I’ll ever use this technique again.

So I checked the pressure. Seems to be Okay, and it blows about 30 (more than the box said it would). It has been humid around here lately (high for Seattle anyway). I think my biggest issue is that maaaybe I didn’t clean it enough, I try to do my best though. Also, the paint in the jars had been sitting a bit, and appeared “goopey” and hard to mix. The thinner I use is “Mona Lisa” Odorless Thinners. It’s good for my apartment, and safe for decals. I usually use Testors Dullcote, though a rattle can was needed to fix my recent SNAFU. I mixed it 3/1 as I usually do. I guess there was some leftover paint lurking and the thinner fired it out of the nozzle? I dunno…but some serious cleaning is in store. Thanks for the help guys.

Kyle

I always use a filter on the airbrush syphon tube; it has saved me from a major clog in the airbrush a number of times when some paint was more goopy than I thought it was. If the filter clogs, I soak it in laquer thiner or 90% rubbing alchol for a few days

http://www.walthers.com/exec/productinfo/165-502016
http://www.walthers.com/exec/productinfo/165-502017

Well that’s your issue then. If the paint has been sitting a while, and appears “goopy” don’t use it. Clean the brush again letting it soak overnight. Get new paint, and report back.

Kyle:

I had the same problem this summer with a new air brush and a new air compressor. I tried everything like cleaning the air brush, changing air pressure etc.

So I took my air brush up to my twin who is a professional taxidermist. We used the same air brush and the same paint with his line and compresor and no problem

I set back up on my outfit again and had the problem again. Splatter!

I did not get back to it as finished the project at his place. However, when I get back to painting I am going to install a moisture trap in the line to the air brush. I am convinced it is moisture coming from my air compressor tank though I did drain it and blow it out. That reminds me, I should bring it in from the garage before our first freeze…

You have a dirty airbrush plain & simple. Just running thinner or reducer thorough it is not enough. You must dissemble the brush and it’s components being careful to A: note the position of every part and a common lover looked item is the length of the needle. B: have your direction available when reassembling. I put all my cleanable parts (no o-rings or Teflon seals) in a bottle of lacquer thinner and let them soak over night even the airbrush body with the plastic end removed if is so equipped I gently clean the needle with a soft cloth and some thinner or 90% Isopropyl Alcohol. Needles will bend very easily so care when handling is a must.Before reassembling your airbrush blow air through all the part about 30 psi holding them firmly of course. (ALWAYS! use a strainer type filter on the pick up tube) and pour your mixed paint through a strainer or cheese cloth when pouring it in to your bottle. May seem like a bit of a pain but it’s all the little things that make a great paint job.

When your cleaned airbrush is reassembled spray straight reducer through it and observe the spray pattern. you may need to adjust it to suit your needs. One should never have spattering or anything else like you’ve described even come close to happening on your model. You should always spray a test pattern on a piece of scrap even a cardboard box will do. Test first then spray. Nothing is more aggravating when painting then what happened to you.

Please accept this as constructive criticism only meant to help you avoid disasters like this in the future. I’ve had an airbrush in my hand professionally for over 30 years so if I am just trying to share something with you that be of some help.

Thanks for the tips and ideas guys. Thursday evening it’s going to get the described cleaning. I have some well cars that need some dirt, and rust. I’ll report back my results, and progress. Like I said, thanks! Oh, and what would you guys thin Polly scale with?

Kyle

Modeling whatever I think looks cool!

I have to bow and admit to stupidity and laziness on this one. I cleaned all of my components with a cotton swab, and thinner. Then I soaked them, and dried them. The paint was flawless, sort of. It came out smooth, and with no blotches, clumps or spatter. You guys were right, my rig was dirty. Thanks for the help!

I gather you’re using a Badger…

[:-^]

John