I urge you to read over this information. If you have never worked with resin castings before, this text contains important information regarding the proper use of your parts; failure to read and follow this information may result in undesirable results. Critical steps to take as soon as you’re parts arrive. The most often overlooked and most important step to take is to clean the parts of any possible mold release before working with them. I use mold release on some parts to help in the de-molding process. It may be impossible to tell what parts may or may not have mold release on them, it is very important to remove any traces of it from your parts before attempting to paint them.
Mold release is colorless, odorless, and may very well be on the part without showing any signs that it is there. Some parts may also feel ‘greasy’ and this is a definite sign of mold release. Other times it may dry from sitting for a long time on a part and may not be felt or noticed but it will be still there. Dry mold release can be “re-moistened” via the painting process causing all kinds of trouble. Please be sure to follow the steps outlined below. If you do not remove the mold release agent the paint may crack or easily flake off, discolor, orange peel, fish eye, or very possibly, not dry at all. As insurance to your part investment, this step is easy and should not be avoided.
Resin Cleaning Tips
This is how to remove mold release from your parts. Assemble your materials needed to clean your parts. You will need a bath towel, cotton balls, Bleach White tire cleaner, rubber gloves, a bottle of isopropyl rubbing alcohol (70% or 90%), dish soap preferably Dawn without hand softening agents, a roll of paper towels and a toothbrush.
Liberally spray bleach white on parts and let soak several minutes, longer the better, rinse in warm water. Use a paper towel to remove excess water. Use one cotton ball or heavy duty paper towel soaked with alcohol per resin part, using the cotton ball now soaked with rubbing alcohol wipe down the resin part in a circular motion to break loose any mold release. For small parts just pour a little alcohol in a container and soak parts for a minute or two. While the part is still wet with rubbing alcohol, place it into the sink and proceed to wash it like you would your dinner dishes using the toothbrush and soapy water. Rinse well and dry thoroughly before priming.
Here is a tip about using primer on resin parts. I strongly recommend that you use a sand-able automotive primer. I personally use Plastikote sand-able automotive primer on all my castings with great results. I usually decant my paint and primers to separate bottles to be applied by air-brush. Start with a light mist coat, let dry for about half hour then prime as usual to fill any imperfections. Recently I have been having trouble finding PlastiKote Primer, I have found that Harbor Freight has a primer called Iron Armor which sands very nice and sticks well to resin.