Urethane rubber is an excellent choice for casting props or costume pieces which require high abrasion resistance and durability. The challenge is finding a paint which will adhere to the surface of the urethane casting.
Some of our customers have found that our Brush-On 40 urethane rubber has excellent adhesion properties and can be used as a paint for urethane rubbers when combined with So-Strong pigments and thinned with mineral spirits.
The pigments must be added to the rubber before the solvent is added, and for this reason, small batches of rubber should be mixed.
In the following example, Brush-On 40 is thinned with mineral spirits, brushed and airbrushed onto the surface of a Reoflex 30 casting.
The frog was cast into a Smooth-Sil 910 mold, making release agent unnecessary. If a release agent were used, it would need to be thoroughly removed from the piece using an appropriate solvent before a casting could be painted.
This finished prop is durable, realistic, and has a long-lasting surface finish.
1 - Brush-On 40, mixing containers and sticks, So-Strong pigments, brushes, mineral spirits and the Reoflex 30 casting are assembled.
2 - The Reoflex 30 casting is removed from the Smooth-Sil 910 mold.
3 - A melamine coated base board is placed on the counter-top.
4 - The frog casting is placed on the melamine board.
5 - The Brush-On 40 rubber is measured out 1A:1B by volume.
6 - The part B of the Brush-On 40 is placed in the mixing container.
7 - The Brush-On 40 part A is combined with the part B.
8 - The material is mixed thoroughly.
9 - A small amount of the mixed material is put into a small cup.
10 - So-Strong brown tint is added.
11 - The pigment is mixed into the material.
12 - A small amount of mineral spirits is added to thin out the Brush-On 40 rubber.
13 - The mineral spirits is mixed in thoroughly.
14 - This mixture is applied as a wash over the entire piece.
15 - Care is taken to coat all surfaces.
16 - The piece is entirely coated with a Brush-On 40 wash.
17 - A heat gun is used to accelerate the curing of the Brush-On 40.
18 - As there is still a small amount of time remaining in the Brush-On 40's pot life, more mixed rubber is dispensed into a small cup.
19 - So-Strong green tint is added.
20 - So-Strong black tint is also added.
21 - The Brush-On 40 and pigments are mixed thoroughly.
22 - Approximately 5 parts mineral spirits is added.
23 - Enough mineral spirits is added to create a thin mixture, about the consistency of milk.
24 - This mixture is poured into an airbrush.
25 - Small details are painted with this airbrush.
26 - The thinned rubber flows through the airbrush smoothly.
27 - The completed skin detail.
28 - Finally, the eyes are painted using the same Brush-On 40 mixture with a brush.
29 - The completed piece is left to cure overnight.
30 - After curing, the completed piece is realistic, and the paint is very durable.