12-21-2008, 06:03 PM
I have used Polly Scale and Modelflex paints for just about all my painting on brass or plastic. My brass Canadian National N-5-d 2-8-0 is painted with Polly Scale. Steam Power black directly on the brass without primer. It stuck real well. For both plastic or brass I thin the Polly Scale with either distiled water or the new Model Master acrylic thinner ( #50496 ). Most of my recent bottles of Polly Scale I purchased suggest the thinner or distiled water. The Modelflex paints are for the most part ready to spray and do not require thinning but I do add some Modelflex 16-600 extender sometimes to slow the drying time.
I found both Polly Scale and Modelflex to be good paints. They just take a little practice to get used to spraying them. Both give good coverage and a nice finish when properly sprayed. My favorite of the two is Modelflex but this is because I have been using it longer and have always had good results. It has a very fine pigment and gives good smooth coverage with a few thin coats. So far Polly Scale seems to be just as good.
True Line Trains here in Canada has come out with their own line of water based acrylics. They are made by one of the top paint manufactures for model paints. I have been told it is Testors based on the Polly Scale paint line ( not really 100% sure about that ) and are ready to spray right out of the bottle. So far they are only offering Canadian colors. I have ordered some as I want to try the warm black they offer. It is supposed to be a good steam locomotive color for indoor lighting.
One thing I have noticed is when over spraying Polly Scale with Testors dullcote or glosscote thinned with lacquer thinner it tends to soften the Polly Scale a bit but once the lacquer thinner flashes off the paint is fine. Modelflex does not seem as affected by the lacquer thinner. To remove Polly Scale from brass a dip in lacquer thinner takes it off quickly but DO NOT do the same with plastic as the lacquer thinner will melt the plastic. Modelflex on brass comes off with lacquer thinner as well but it takes a lot longer.
I have removed Modelflex from plastic using 99% Isopropyl alcohol and brake fluid. Be carefull with the brake fluid as it effects some plastics. Always test in a hidden spot first. I would imagine both should remove Polly Scale from plastic but I have not tried it yet.
Water based paints tend to clog the airbrush tip more than solvent based paints due to their faster drying times. This is where a double action airbrush helps as when you release the trigger the tip closes which helps with tip clogging. I keep a small cup and a small sponge close by with a little lacquer thinner in it and wipe the airbrush tip once and awhile when spraying.
Another trick for spraying masked edges is not to spray directly toward the masked edge as this can force paint under the tape edge. Keep you spray pattern so it is 90 degrees to the tape edge or away from the tape edge. Less chance of paint bleeding under the tape.
I have also found 25 to 30 PSI is best for spraying water based paints. When I spray Testors dullcote or glosscote thinned 50% with lacquer thinner I only use 15 PSI as I find any higher the lacquer is too dry when it hits the model.
All my spraying is done with either my Badger model 175 ( double action, medium or fine tip ) or model 200 airbrush ( single action with fine tip ). When I am finished I spray clean water through them and then they are carefully cleaned with some lacquer thinner to make sure they are completly clean.
Wayne Reid
I found both Polly Scale and Modelflex to be good paints. They just take a little practice to get used to spraying them. Both give good coverage and a nice finish when properly sprayed. My favorite of the two is Modelflex but this is because I have been using it longer and have always had good results. It has a very fine pigment and gives good smooth coverage with a few thin coats. So far Polly Scale seems to be just as good.
True Line Trains here in Canada has come out with their own line of water based acrylics. They are made by one of the top paint manufactures for model paints. I have been told it is Testors based on the Polly Scale paint line ( not really 100% sure about that ) and are ready to spray right out of the bottle. So far they are only offering Canadian colors. I have ordered some as I want to try the warm black they offer. It is supposed to be a good steam locomotive color for indoor lighting.
One thing I have noticed is when over spraying Polly Scale with Testors dullcote or glosscote thinned with lacquer thinner it tends to soften the Polly Scale a bit but once the lacquer thinner flashes off the paint is fine. Modelflex does not seem as affected by the lacquer thinner. To remove Polly Scale from brass a dip in lacquer thinner takes it off quickly but DO NOT do the same with plastic as the lacquer thinner will melt the plastic. Modelflex on brass comes off with lacquer thinner as well but it takes a lot longer.
I have removed Modelflex from plastic using 99% Isopropyl alcohol and brake fluid. Be carefull with the brake fluid as it effects some plastics. Always test in a hidden spot first. I would imagine both should remove Polly Scale from plastic but I have not tried it yet.
Water based paints tend to clog the airbrush tip more than solvent based paints due to their faster drying times. This is where a double action airbrush helps as when you release the trigger the tip closes which helps with tip clogging. I keep a small cup and a small sponge close by with a little lacquer thinner in it and wipe the airbrush tip once and awhile when spraying.
Another trick for spraying masked edges is not to spray directly toward the masked edge as this can force paint under the tape edge. Keep you spray pattern so it is 90 degrees to the tape edge or away from the tape edge. Less chance of paint bleeding under the tape.
I have also found 25 to 30 PSI is best for spraying water based paints. When I spray Testors dullcote or glosscote thinned 50% with lacquer thinner I only use 15 PSI as I find any higher the lacquer is too dry when it hits the model.
All my spraying is done with either my Badger model 175 ( double action, medium or fine tip ) or model 200 airbrush ( single action with fine tip ). When I am finished I spray clean water through them and then they are carefully cleaned with some lacquer thinner to make sure they are completly clean.
Wayne Reid