Hybrid Casting

[Racer3770]

I need some expert advice from those of you that stabilize your own woods and cast them with alumilite. I just got into stabilizing using the turntex system.
I dry the wood in a toaster over at about 250 degrees overnight. I let it cool and stabilize it except I've never got the bubbling to stop. I've run three or four batches under vacuum for 24-36 hours at a time.
When I cast the wood with alumilite, it's like it still has moisture in it, even though it's stabilized. I think this is my issue. Can anyone offer some advice? I get bubbles and gaps between alumilite and wood. I cast at 60-65 PSI. Makes for some ugly blanks.

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[mark james]

I know you want them to come out clear; but don't abandon the ones that are white (yes, with moisture!) because they are beautiful!

Keep tweaking your process. I suspect the wood is still too wet. Hopefully others with more experience will add comments.

May want to call Curtis.

 

[magpens]

Good luck working on this, James.

But please do not stop making your all-Alumilite blanks without wood .... I like them best.

 

[robutacion]

I need some expert advice from those of you that stabilize your own woods and cast them with alumilite. I just got into stabilizing using the turntex system.
I dry the wood in a toaster over at about 250 degrees overnight. I let it cool and stabilize it except I've never got the bubbling to stop. I've run three or four batches under vacuum for 24-36 hours at a time.
When I cast the wood with alumilite, it's like it still has moisture in it, even though it's stabilized. I think this is my issue. Can anyone offer some advice? I get bubbles and gaps between alumilite and wood. I cast at 60-65 PSI. Makes for some ugly blanks.

]

I never use Alumilite but from what I know of that resin, you shouldn't have those issues.

I'm a little sceptical when you say that the bubbles never stop when you are stabilizing, even after a lot longer than it should, in my experience and with the set-up I've got, you should get it done in less than 6 hours. I wonder if you have an air leak on your stabilizing system, if air gets in, it will never reach full vacuum and you should notice the gauge reading low.

I don't know what woods you used and where you've got them from but if the wood was green, that drying time is not sufficient and you may achieve better results if you try to get a forced fan oven and use about 60° Celsius to dry them out slowly but surelly, expect about 3 full days (72 hours) at least to dry green wood and off-course, the drying time will depend on the size of the pieces of wood you are trying to dry, the smaller the faster it will dry however, you need to count with shrinkage and bowing/warping

The pot pressure for the casting should be enough, that pressure will force air and moisture out of the wood and that is normally what makes the casting to look like yours.

Try to eliminate one thing at the time, you will find the cause and get better results afterwards.

Good luck,

Cheers
George

 

[Racer3770]

Good luck working on this, James.

But please do not stop making your all-Alumilite blanks without wood .... I like them best.

Thank you! Certainly not in the plans. I just enjoy making different things. I have a whole vacuum set up that feels pretty useless to me until I get this figured out.

 

[Racer3770]

I need some expert advice from those of you that stabilize your own woods and cast them with alumilite. I just got into stabilizing using the turntex system.

I dry the wood in a toaster over at about 250 degrees overnight. I let it cool and stabilize it except I've never got the bubbling to stop. I've run three or four batches under vacuum for 24-36 hours at a time.

When I cast the wood with alumilite, it's like it still has moisture in it, even though it's stabilized. I think this is my issue. Can anyone offer some advice? I get bubbles and gaps between alumilite and wood. I cast at 60-65 PSI. Makes for some ugly blanks.



]

I never use Alumilite but from what I know of that resin, you shouldn't have those issues.



I'm a little sceptical when you say that the bubbles never stop when you are stabilizing, even after a lot longer than it should, in my experience and with the set-up I've got, you should get it done in less than 6 hours. I wonder if you have an air leak on your stabilizing system, if air gets in, it will never reach full vacuum and you should notice the gauge reading low.



I don't know what woods you used and where you've got them from but if the wood was green, that drying time is not sufficient and you may achieve better results if you try to get a forced fan oven and use about 60° Celsius to dry them out slowly but surelly, expect about 3 full days (72 hours) at least to dry green wood and off-course, the drying time will depend on the size of the pieces of wood you are trying to dry, the smaller the faster it will dry however, you need to count with shrinkage and bowing/warping



The pot pressure for the casting should be enough, that pressure will force air and moisture out of the wood and that is normally what makes the casting to look like yours.



Try to eliminate one thing at the time, you will find the cause and get better results afterwards.



Good luck,



Cheers

George

George,
Thanks for the reply! All of my vacuum equipment and stabilizing chamber is basically brand new. I calculated the maximum theoretical vacuum for my conditions and I'm right on it. I cut the wood I'm drying into very tiny chunks in hopes that it would dry faster.

When you take items out of the oven, how do you keep the atmospheric moisture from re-entering the wood? I have tried vacuum sealing them in a plastic container until they cool down. I've also tried using ziplock bags (the wood melts them).

I think you're correct about my drying time not being long enough. I will have to try drying the wood for longer. Thank you!


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[KenV]

My bet is the wood is not dry.

Get out the little digital postal scale. Weigh the wood and record the weight. Put it in the oven for a day. Weigh it and record the weight. Put it back in the oven and give it another day. Repeat the weighing and drying intil you get the exact same weight 2 or more days in a row.

3-4 days is more likely the answer, and it may take a week or more for dense woods.

 

[arkie]

Moisture...

Suspect it is not dry. You need a longer time to dry and that is if the wood is already "dry" (at ambient moisture). The continued bubbling is probably moisture outgassing under vacuum, indication your wood is not dry.

Also, the stabilized wood can reabsorb moisture even if it is dry..

You need to have conversations with Curtis about this, but he is teaching at Arrowmont for a few more days. Give him a call next week.

Jim

I dry the wood in a toaster over at about 250 degrees overnight. I let it cool and stabilize it except I've never got the bubbling to stop. I've run three or four batches under vacuum for 24-36 hours at a time.
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[eharri446]

Also, with Alumilite casting, you have to use a pressure pot to ensure that you do not get air bubbles. With PR you can get by with out one.

 

[mikepet]

You might consider doing what I have done instead.

I have made various objects out of wood or corian, such as a letter, or a cross, or even Xs which will become 1/2 celtic knots. Then pour the resin over them in the mold. That seems to have worked well for me.


You can also make fatter than normal resin pen blank and then cross cut them to use as veneer for filling celtic knots and other cuts. Or cut chunks of the resin and add them as segments for the wooden designs.

The idea is that you can still use both wood and resin in your designs, but without needing to mix them quite as much.

 

[Racer3770]

Update:
Wood has been in the oven since early Sunday at about 275 degrees. I removed them into a ziploc bag to cool for a few minutes. After they cooled, I fired up the cactus juice. Everybody cross your fingers!

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[mikepet]

I just saw a video on youtube pop up. Apparently the term is called ShokWood. There is a 30 min video on how to make it. You might look this up and see if it answers some of your questions.