You have many options for Vertical molds. I’ll start by discussing Schedule 40 PVC. It is what I use to casting in. The inside diameter of the 1/2”, 3/4” and 1” pipe work well for pen sized blanks. The Poly Resin is a heat cured process so as the blank sets, it will shrink. That shrinkage will all you to remove the blank from the PVC. I normally use a wood dowel and a rubber mallet. I’ve had some people complain that they haven’t been able to remove the blank from the PVC. I think this is because the blank hasn’t full cured.
(Caution: the next step should be used at your own risk)
I fully cure my blanks in a low heat oven. I caution you not to put the blanks in liquid form in the oven. By low oven I mean the lowest setting. Ours is 170 degrees. I wouldn’t exceed 200 degrees. You can use a toaster oven but I haven’t had much success using one. I always get the blanks too hot and melt the PVC, and it is flammable. I wait until the resin is solid to the touch at the top of the PVC pipe. If you don’t want to use the oven method, you can sit the blanks in the hot sun and this should cure them. I don’t use any type of mold release.
There are several different methods to plugging the end of the PVC. I use #10 corks that I buy from WidgetCo. (http://www.widgetco.com/) I’ll use some type of plastic food wrap to cover the cork before I insert it in the tube. I try to keep the resin from soaking into the cork. I can get 15-25 uses out of the cork stoppers. Some people have had luck using rubber stoppers. The advantage of rubber is that the resin won’t ruin the stopper.
Some casters use different type of tape to seal the end of the PVC pipe. Again, I have tried it but was more successful with cork stoppers.
Note: PVC should not be used for Alumilite unless you plan to use the lathe to turn off the PVC from the pen blank.
There are several vendors that make vertical molds using urethane or silicone rubber. One
that comes to mind is Fred Wissen at http://www.ptownsubbie.com. He has 3/4” x 6” blank rubber mold.
If you feel advantageous and want to make your own molds, I have a video on Youtube on using Smooth-On’s (http://www.smooth-on.com) OOMOO 30 silicone rubber. It is an easy to use compound that doesn’t
require vacuum degassing and is easy to mix and pour. Check out the video here (http://youtu.be/E7LgSzuzXt0)
I’ve seen others use baby soda bottles. I haven’t tried it. Just seems that the blanks would be hard to get out. One advantage, you wouldn’t have to cork the mold. One last item before I close this blog
post. I have used aluminum wrap or foil to make a one-time use mold. I took some foil and wrapped it tightly around wood dowel of the size I wanted for my finished blank. I guess you could use another pen blank. Most likely the foil will stick to the resin and have to be turned off.