mess

[montmill]

I have a maple blank with a decal on it. The blank was finished with CA and left to dry several days. The decal printed, sprayed with fixative and allowed to dry several days. The decal was applied to the blank and allowed to dry several days when it was finished with a CA finish. It cured for at least two weeks.

Today I cast it in alumilite water clear and after an hour in the pressure pot at 60 psi I took it out. There was some extra alumilite in a cup that had completely set up but the blank in the pot was still soft. I put it in a toaster over on warm for 20 minutes and bubbles appeared all along the decal and in the alumilite. When I removed it from the mold the bottom was still soft and mushy.

Did I read that alumilite and CA don't mix, that I should have used Silmar 41?

Thanks for any help.

Montmill

 

[Monty]

You probably had some residual moisture in the maple blank. Alumilite does not like moisture at all. I always dry my wood blanks in several 30 second cycles in the microwave until the MC is almost 0. I believe Curtis dries his wood in a regular oven at about 120*F overnight before he casts in Alumilite.

 

[PTownSubbie]

I am not quite certain why you are trying to cast over a waterslide decal. You shouldn't have to do any casting with what you are trying to do. You can turn your blank, apply the decal and then CA finish your pen.

The casting was likely not fully mixed and took longer than you expected to fully cure. Also, blanks cure slower in a pressure pot. At least they do for me.... Can't explain why, I have figured it out the hard way. Leave them in there for twice the time you expect.....

Good luck!

 

[montmill]

Thanks for the feedback. I suspect moisture was the problem. I'll put another in a toaster oven and let it dry completely before trying again.

Regarding the mixing, the material that was left in the cup outside the pot set up perfectly clear and hard. Perhaps I should leave it under pressure longer than an hour.

Thanks again for your help.

Montmill

 

[montmill]

The second blank was in a warming oven over night and left in the pressure pot for four hours. Still had bubbles though not as bad.

No more casting over wood with alumilite for me.

Montmill

 

[Monty]

Where are you located? Maybe if you posted where you live someone nearby may be able to give a demo on casting with Alumilite.

 

[BSea]

I can't explain why the alumilite in the cup set up, and what was poured did not. Usually, if it isn't mixed well, you get soft spots, but not soft all over. However, I've not used the water clear, so that may have something to do with it.

 

[MesquiteMan]

It did not set up because most likely you did not have enough Alumilite to get a good exothermic reaction ( not enough heat). Try placing your mold ready to go in a toaster oven at 140 f or so for 20-30 minutes. Then cast while still hot.

 

[PTownSubbie]

It did not set up because most likely you did not have enough Alumilite to get a good exothermic reaction ( not enough heat). Try placing your mold ready to go in a toaster oven at 140 f or so for 20-30 minutes. Then cast while still hot.

Curtis,

I thought Alumilite didn't need the heat (although it helps)....I thought the process was a chemical reaction between part A and B that creates heat as a by product...

Thought it was totally different than PR.....

Confused

 

[MesquiteMan]

In small, thin sections, heat is needed. With either PR or Alumilite, the chemical reaction creates heat which accelerates the chemical reaction, which creates more heat... Basically creating a run away reaction. In thin sections, there is frequently not enough heat created to cause that run away reaction and you get a partial cure.

 

[PTownSubbie]

In small, thin sections, heat is needed. With either PR or Alumilite, the chemical reaction creates heat which accelerates the chemical reaction, which creates more heat... Basically creating a run away reaction. In thin sections, there is frequently not enough heat created to cause that run away reaction and you get a partial cure.

Do you have a feel for how thin this has to be to not have enough to react? It would seem that a pen blank in a mold would have enough volume. Could it have been a combination of poor mixing even if the cup still cured?

Just wondering...

 

[montmill]

A picture of the blank in question:

 

[montmill]

When I tried to turn the blank above the alumilite broke loose from the blank and took the decal with it. Go figure.

Montmill