Help with painting polystyrene
01-13-2006 | 10:30 AM
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From: Plattsmouth,
NE
Help with painting polystyrene
Howdy all,
I made a cowl with my vacuum table for a scratch built model I have just finished. The problem is this. I painted the cowl with Top Flight Monokote Paint to match the Monokote. The result was that the paint made the plastic very soft and actually deformed it. I made the cowl using 30 mil high impact polystyrene (HIPS). This model only has a 20" WS so the cowl isn't very thick. It is electric so fuel proofing is not required. I am also working on a I.C. powered plane that will have a cowl and wheel pants made from the same polystyrene. What do I use to paint polystyrene and not have the piece wrecked due to some kind of chemical reaction?
Hec
I made a cowl with my vacuum table for a scratch built model I have just finished. The problem is this. I painted the cowl with Top Flight Monokote Paint to match the Monokote. The result was that the paint made the plastic very soft and actually deformed it. I made the cowl using 30 mil high impact polystyrene (HIPS). This model only has a 20" WS so the cowl isn't very thick. It is electric so fuel proofing is not required. I am also working on a I.C. powered plane that will have a cowl and wheel pants made from the same polystyrene. What do I use to paint polystyrene and not have the piece wrecked due to some kind of chemical reaction?
Hec
01-13-2006 | 12:07 PM
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From: Manvel,
TX
RE: Help with painting polystyrene
If you can find a color match you can use an enamel based paint such as Testors or you can use a Krylon product called Fusion but if very light coats of the Top Flight paint are applied there should be no problem on styrene. Just hold the can off the part about a foot and make several light passes.
01-13-2006 | 12:30 PM
#3
RE: Help with painting polystyrene
googled for "painting styrene" and came up with this:
PAINTING STYRENE
Most paints will stick to styrene well enough to allow them to be used indoors in locations that will not require a lot of handling. For brush applications, oil based paints such as Testors flat colours, and various brands of water based acrylics work particularly well. Household latexes also work, but the heavy coats needed for colour coverage tend to obscure fine details. Lacquers such as Floquil or Scale Coat are not recommended for brushing on styrene.
Where a lot of handling is required, for example rolling stock, or where the project will be exposed to the weather, lacquer applied with an air brush is the best choice. The author's top choice is Floquil thinned with Diosol, applied without a barrier coat. When applied with an air brush in light coats, it attacks the surface of the styrene just enough to make a really strong bond without causing crazing. A bit of practice with some styrene scraps goes a long way toward finding out just how light or heavy a coat to use. An expensive new engine shell or a structure that has taken many hours to complete are NOT good places to practice. And NEVER use spray cans of lacquer directly on styrene - the flood of material that they produce is guaranteed to cause problems.
Other workers report good success with water based paints applied with an air brush. The author's hesitation in endorsing them lies solely in his inexperience with them. Their advantages seem obvious - easy cleanup with water and no harmful solvents that require using a spray both and/or a mask to absorb the vapours. However, plain water may not completely clean the air brush, and a good mask to absorb the mist of fine droplets of paint is still necessary. Not to put too fine a point on the latter, IF YOU BLOW, YOU KNOW. Blow your nose on a white tissue right after your paint job. If there is any paint colour at all on the tissue, your mask is not working well enough.
Often the durability of paint can be improved by applying a clear top coat over it. Testors Dulcote is often used indoors, and it works wonders in protecting decals and dry transfers in addition to the paint. Outdoors, Dulcote tends to become milky, and the heavier the applied coating, the milkier it becomes. The look is reminiscent of the chalky surface of self cleaning house paint and is often acceptable, particularly as there does not seem to be an alternative.
Most paints will stick to styrene well enough to allow them to be used indoors in locations that will not require a lot of handling. For brush applications, oil based paints such as Testors flat colours, and various brands of water based acrylics work particularly well. Household latexes also work, but the heavy coats needed for colour coverage tend to obscure fine details. Lacquers such as Floquil or Scale Coat are not recommended for brushing on styrene.
Where a lot of handling is required, for example rolling stock, or where the project will be exposed to the weather, lacquer applied with an air brush is the best choice. The author's top choice is Floquil thinned with Diosol, applied without a barrier coat. When applied with an air brush in light coats, it attacks the surface of the styrene just enough to make a really strong bond without causing crazing. A bit of practice with some styrene scraps goes a long way toward finding out just how light or heavy a coat to use. An expensive new engine shell or a structure that has taken many hours to complete are NOT good places to practice. And NEVER use spray cans of lacquer directly on styrene - the flood of material that they produce is guaranteed to cause problems.
Other workers report good success with water based paints applied with an air brush. The author's hesitation in endorsing them lies solely in his inexperience with them. Their advantages seem obvious - easy cleanup with water and no harmful solvents that require using a spray both and/or a mask to absorb the vapours. However, plain water may not completely clean the air brush, and a good mask to absorb the mist of fine droplets of paint is still necessary. Not to put too fine a point on the latter, IF YOU BLOW, YOU KNOW. Blow your nose on a white tissue right after your paint job. If there is any paint colour at all on the tissue, your mask is not working well enough.
Often the durability of paint can be improved by applying a clear top coat over it. Testors Dulcote is often used indoors, and it works wonders in protecting decals and dry transfers in addition to the paint. Outdoors, Dulcote tends to become milky, and the heavier the applied coating, the milkier it becomes. The look is reminiscent of the chalky surface of self cleaning house paint and is often acceptable, particularly as there does not seem to be an alternative.
