[ Allegheny,- but to say it drys in the airbrush itself is ridiculous.]
I should have "clarified" my post as well.
1. In my past posts regarding airbrush spraying, I usually recommend practicing on what I call "junker" model railroad rolling stock or locomotive shells. I have a small pile of Bachmann and Lifelike shells that I obtained at train shows for pennies on the dollar. HOWEVER, for testing your spray pattern as well as your paint's flowout characteristics; a smooth flat surface is excellent.......especially helpful if you're spraying a product you haven't tried before or a thinner than normal mix (such as for weathering). When I ran the collision repair shop at a transit authority, my crew and I always kept a scrap pile of flat panels handy to test our spray guns and airbrushes. Those flat pieces helped us avoid costly mistakes.
As for the statement about paint drying in the airbrush being "ridiculous"........might be to some but I've actually experienced this before, especially living in Florida. After my airbrush clogged with an acrylic/alcohol mix, I took it apart to clean it thoroughly. I cut down the amount of alcohol that I mixed in my acrylic paints and was fine afterwards. My home is airconditioned but my garage is not and is rather toasty in there. I realized that with my high watt incandescent lamp bulb positioned closely to my paint stand when I'm airbrushing, the temperature in that area is even warmer.
"I like my Pullman Standards & Budds in Stainless Steel flavors, thank you!"
Allegheny2-6-6-6but to say it drys in the airbrush itself is ridiculous
I never said that.
I edited my post to clarify that I was talking about the thinner mix, not the paint to thinner mix. For paint to thinner ratio, I just add my thinner mix until I get the milk consistency, sometimes it's a few drops, sometimes it can be as much as 10% thinner, it varies, so milk consistency is what you're after.
Jay
C-415 Build: https://imageshack.com/a/tShC/1
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Wayne's advice is the best you can get. No matter what anyone thinks or tells you no one knows more about the product then the folks who make it. I have heard of some out right wacky concoctions when it comes to reducing paint. I use 79% alcohol with zero negative effects. Being as most of the model railroad finishes are dull or at best satin finish a fast drying time is inconsequential. What give a paint job it's smoothness aka gloss finish is the time it has to "flow out". The longer the flow time the smoother the finish. When a dull or satin finish is what your trying to achieve a faster drying time = Les flow time is what you want. Yes it's true that the accelerated dry time can in some cases have paint build up at the tip of the airbrush but to say it drys in the airbrush itself is ridiculous. To get past this issue keep a couple of Q-tip handy and dab one into some Alcohol and just clean the tip of the airbrush if required. Remember your not painting a car or a semi truck so your actual paint time is not very long at all.
In cases where I have painted gloss finishes on models I have used DI (deionized) water. For me it's as simple as going over to the wall and turning a valve. When my old company went out of business they had a garage sale of sorts and I purchased a DI machine that I had install less then a year before the company closed for $25.00. It cost the company over $2000 new. Now DI is excellent for painting and science experiments etc. but unlike your Britta filtered water your not going to want to drink DI water.
One thing every painter who wants to become better at his craft must do is practice, practice, practice. Yes acrylic CD Jewel cases and other like materials are ok for testing things like spray pattern but you need to practice on what your going to paint. In this case model railroad rolling stock and locomotives. What I and a lot of guys do is scan places like craigslist.com or local papers etc. for cheap train set quality rolling stock and engines.and experiment with your thinning ratio's if you feel the need to. Spraying something like a piece of rolling stock is quite different then painting a sheet of flat plastic. This way you can also develop not only your painting skills but also weathering techniques using your airbrush.
Chris,
Excellent tips from Modelmaker. Since it is cheap, I use distilled water for Pollyscale. It does make a difference since we have hardwater in my area. The gallon I have is still 3/4 full after 3 years of a number of paint jobs. Adding the 70% alcohol is helpful, but be aware that if you're spraying in a warm environment, your paint may start to dry inside of the airbrush. 80/20 is a good mix. The area I spray in averages a temperature range from 75 to 80 degrees from April to November, so I keep my mixes 90% paint thinned with distilled water to 10% alcohol.
Always good to have some scrap plastic material and/or junk model/toy railroad cars to test your airbrush on. One item that nowadays is often discarded is the transparent plastic music CD case! The smooth surface is great for testing your airbrush paint mixes on. Businesses often get CDs with promotional spam or demonstrator type material on them and these often go straight to the trash! I've gotten several CD cases this way. Just check with coworkers, your boss, or friends and ask them to save any cases for you they don't want.
For most paints, a good place to start is by reading the label.
Wayne
First off, it's Polyscale, not Poly S. Poly S was a paint made by the same company many years ago and long since discontinued.
If you're not using the Polyscale thinner, then clean soft water can be used, however since most people have more hard water, (higher mineral and calcium content which can cause stains), most people use distilled water. You could also use a Brita filter on your tap, instead of lugging water jugs around.
For thinner, (reuse the Polyscale thinner bottle), I use an 80/20 mix of water to 70% isopropl alcohol to help the paint flow and cut the surface tension (prevents beading up on the surface). Some folks use just the alcohol, but I find it speeds up the dying too much and often causes buildup of dried paint at the tip of the airbrush. Others use just water. Experiment.
Whichever you use, you want the paint to have the consistency of milk. You should also screen your paint before shooting it through the airbrush and use a clean bottle to spray from. The compressor should be set between 20-30 psi and spray from about 6-8" from the model. Practice, practice, practice.
What is the best productct for thinning Poy S paint. Do I want to use 70% Isolprol alcohol or
disstill water? I haven't paint much. I have a compressor.
Thanks
Chris