Newbie Questions

[THarvey]

I bought some casting resin from our local Hobby Lobby.

I misread the instructions and did not put enough catalyst in the first batch. Those are a little sticky. I know they will eventually setup. I have encouraged them some with a warm oven.

I used the ice tube molds, that someone suggested a week or back.

Questions:

1. I have removed the sticky blanks from the mold. Should I put them back in a warm oven (150*F) on a metal pan? Would that help the harden more?

2. What can I use to clean the mold, before my next casting adventure?

I am sure I have more questions, but those are the two on my mind right now.

Thanks in advance.

 

[NewLondon88]

Yes, you can put them back in the oven, they will harden. It doesn't have to be hot,
150 or so is fine .. just make sure it is an oven that will NEVER BE USED FOR FOOD.
(that stuff is nasty!)

Cleanup.. if it's sticky, acetone should help. If it is hardened, the acetone won't touch
it. Then again, if it is hardened, it should pop out. Freezing the mold should also make
it easy to pop out. Transfer punch works well .. as do chopsticks, popsicle sticks etc.

If it is just general cleanup (nothing stuck) then soap and water is fine.. if anything.
It isn't really needed, as the resin that touches the mold is resin that you'll be turning
away anyway.

 

[DurocShark]

1. I use less than half the recommended amount of hardener nowadays. I put just enough in to make the resin gel, then into the oven it goes. 2 hrs at 170* almost always does the trick. And doing it this way I don't have to post-cure anymore. Plus, since I don't use pressure, the lower amount of MEKP allows slower gelling which means more bubbles work themselves out. So to answer your question, yes. Oven for a couple hours will harden it nicely.

2. Why clean it? Unless you need pristine castings for something, any resin that is left behind will only stick to the outside of your new casting and it'll be turned away. If there's any sticky stuff, depending on the mold I'll either put it in the oven with my blanks or if it can't take the heat, on my dashboard facing the afternoon sun. That will harden it so you can usually pop it off of most materials.