Hi gang, I need some advice on mixing Polly Scale paints for weathering with a airbrush. I’m building the Walthers Modern Roundhouse. I airbrushed the outer walls with Oxide red for my brick color, and it came out well. Then I then started weathering, and used Grimy Black, mixing it with around 50% distilled water (I’m a throwback to the old Floquil days) as I didn’t want the grimy black to totally hide my brick color. The goal was to build up several light coats. The first pass seemed to be going well initially, then the paint started to splatter, going on too wet. I’m using a Paasche H. At first, I had the regulator set at 20 psi, then turned it down to about 12 psi and still got the splatters. Obviously I thinned the paint too much. I’m curious what mixture has worked for others when weathering with this paint, and what psi was used. As usual, thanks in advance for any help.
The one and only time I ever tried using Polly Scale paint I ended up having to go to almost 35 PSI to get it to spray properly which is way to much if the item you’re spraying is small and light, it blows it away!! But, Polly Scale does require more pressure than solvent based paints.
My normal pressure for spraying is about 15psi tops with standard solvent based paint thinning it to about a 60/40 paint to thinner mix depending on the color of the paint and what I’m painting.
I do know that Polly Scale won’t spray worth a darn if it isn’t “completely” mixed, any lumps no matter how small will really mess things up, but again the only thing about spraying with it for sure is it requires more pressure.
Mark
Forty Niner, I miss the good old days of using solvent based Floquil thinned with Diosol. I take it Floquil is still made, but maybe a different formula and thinner. All my LHS carries is the Polly Scale and some Testor’s. I do pretty good spraying the basic color coat, and thin it with distilled water. I got a strainer to go on the end of the cap siphon, and that has helped reduce problems with the lumps you described. However, weathering is relatively new to me; I don’t need the mix so thick that it totally covers the base color.
While I still prefer Floquil and other lacquer-based paints, I also use PollyScale. For regular painting with an air brush, I use distilled water - the bottle recommends 25% thinner for airbrush use but I vary that as required. For weathering, I use up to 90% distilled water. My airbrush is a Paasche VL, and I use the medium-size tip for all painting and weathering, with a pressure of 15-20psi. The key to successful application is to build-up the coverage slowly - that’s the primary reason for using such a large percentage of thinner - so adjust the needle (or your technique) to spray less paint with each pass. Heavier weathering obviously requires more paint, but it needs to be built-up with successive applications rather than one or two heavy ones.
When I initially began using PollyScale, I followed the advice of several folks who had supposedly good success using alcohol or windshield washer fluid as a thinner, with a spray pressure of about 35psi. This proved totally unworkable for me, with the tip clogging on almost every pass. Clean-up was a nightmare and I relegated the PollyScale to brushed applications only. When it became difficult to obtain some colours of Floquil locally, I decided to make another attempt with PollyScale. This time, though, I consulted the Testors’ site for information. After you “Select Your Application”, click on “FAQ” at the top of the page for lots of tips and advice on paint application. Following the suggestions, I successfully painted more than 40 cars in a single session, without a single incident of clogging and PollyScale has become a well-used resource in my paint cupboard.
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Additives like alcohol or windshield washer fluid (which includes glycol) make acrylics dry faster, the exact opposite of what we want some times.
Thinning with distilled water (a gallon costs less than $2) and adding one or two drops of an acrylic retarder like Createx Additive Retarder or Liquitex Slow-Dri Fluid Retarder will make the paint lay down nicely and help to keep paint from drying in the airbrush.
For weathering, I like no more than 1 part of paint to 9 parts of thinner, whether it’s for Floquil or PollyScale. That gives me a nice tint and it’s easy to deepen the colors with multiple passes.
Thanks for the responses. I will try the 90% thinner and 10% paint mix, and switch to the medium cone and nozzle. Building up the weathering with multiple passes is what I had in mind. I’ll try this after work tomorrow and post the results here. Thanks again!
You can add up 20% 70%-Iso Alcohol to the water (thinner) without affecting the drying time and it does help the paint to flow nicely. I keep my thinner premixed (80% water/20% alcohol) in a separate bottle ready to use.
I agree on the 9 to 1 ratio for weathering. For straight painting, throw out the ratios as Polyscale’s thickness is inconsistent. Instead add thinner until the paint is the consistency of 2% milk to whole milk, (if you’re new to acrylics it helps to have a glass with a bit of milk in it near you so you can slosh it around and compare to the paint). I posted some other tips in this thread: http://cs.trains.com/TRCCS/forums/t/185804.aspx and http://cs.trains.com/TRCCS/forums/t/185804.aspx?PageIndex=2
I can’t believe it took me 10 days before I tried weathering again. Such is life sometimes. I mixed the Grimy Black 1 part to 9 parts distilled water, and switched the airbrush nozzle and tip to medium. Then I airbrushed at 18 psi. This did provide the look I wanted, gradually building up the weathering. Apparently this is the right formula for weathering acrylics with a Paasche H. Thanks to all who responded!!