Monday, February 14, 2011
How To Cast In Resin Part II
Well, we're back with another installment of "How To Cast In Resin." Today I will be documenting the steps that I take to cast my resin pieces. Let's get started!
You will need everything mentioned in the previous post if you wish to follow along EXACTLY, but there are substitutions. A few items that i may have missed in the prior post are discussed below:
Surfactant- This stuff is used to keep the resin from sticking to the mold and causing damage over time. It allows your casts to slide right out of the molds. You can use a mix of Jet Dry dishwashing detergent and water, but I prefer to use this:
Step 1: Just soak while you are preparing the rest of the items that you will be using. Fill up a bucket of your Jet Dry mix as a first step so you can let them sit. When you are ready to grab your molds out, agitate them a bit with your hands as shown. Stick your fingers down into the recesses to get out any residual powder residue. Remember that your first cast will likely not be perfect but the subsequent casts following this will turn out nicely if all is done correctly. You can always use the first casts for rubble.
**Note that you do not want to pour the resin into a wet mold!
Step 5: Place the mixture into a vacuum chamber and turn on the pump. You want to get as close to 29 HG as possible, note that 30 HG is Full Vacuum. You will notice all of the air bubbles rising to the surface, and at 29 HG, the bubbles will begin to boil up and pop. Once this begins, you are okay to turn off the vacuum pump and SLOWLY let air back into the chamber. If you perform this step too quickly, you will have a huge mess to clean up.
***Remember the cure time of your resin here, taking too much time on this step will result in a block of resin in your cup. Do not throw this out though, because i can be used as a display base if you can put it on a lathe.
Step 6: I like to place my mold in the pressure pot and pour it in there. This keeps the mess isolated only to my pot. Do not pour the resin into a cavity, pour it onto the top of the mold near a corner of a cavity and let the resin roll into the mold. When you are finished pouring, put the lid on the pot and blast air into it. Keep the pressure below 60 PSI, as you do not want to damage your pot. Notice the closeup of my setup. There is a ball valve located just after the input to lock the pressure in. This is also used to let the pressure out.
Step 7: When the resin in your cup is nice and hard, remove the mold from your pot, and de-mold your pieces. If everything went well, you should be well on your way casting bubble free pieces. Good luck and if there are any questions, please ask them in the comments section.
Posted by James Swallow at 9:42 AM