10-10-2015, 08:42 AM
Mr Fixit Wrote:As far as bubbles in your resin mix, one tip I have seen used when casting water features is to use a stick or tool as a chute to pour the resin down to the molding surface to avoid air bubbles.
Another tip maybe to use a vibration device to help settle the resin into all the parts of the mold and float up any air bubbles.
It's actually kind of ironic for me that you say this, the other day in studio we were attempting to cast models in Rockite (in case you don't know, basically just portland cement without any aggregate or other additives) and found out how to fix many of the techniques you mentioned. We even used an oscillating grout remover tool with a stick attached to vibrate the cement down into our molds! Very cool stuff, just never realized that I could apply it to resin casting.
Green_Elite_Cab Wrote:I've been using Alumilite with some success. They sell a variety of resins and rubbers with different properties that might help you.
The mold rubber will break down over time, but Stuff like HS2 and HS3 (tough and rubbery, respectively) can withstand much punishment.
Is HS3 the pink or blue rubber stuff, like I've seen used in Model Railroader? Ever since I tried with Composimold I couldn't help thinking that my molds may work better if I tried this stuff. Especially since I want to repeatedly reuse the mold. I appreciated the step-by-step ideas you gave me in your first post, I have been thinking about how to make a better mold and try it again. The only thing I can't figure out is where to put the conduit to pour into and the conduit for air to escape without trapping some bubbles around the gondola body, or without having a significant area to carve away afterward, do you have any ideas for these? Questions like this are basically the main things that discouraged me from trying to cast again.