Freeze Drying

[Dale Hatfield]

Been trying to figure out. If I should buy a used chest /deep freezer. To stick carvings into. Been reading about freeze drying wood . It seams that relics from digs and sunken treasures have been freeze dried with peg 200 to prevent the fast rot that happens.
Any bowl turners hand carvers of green wood ever freeze dry anything.
I guess to test would be to weight a fresh small carving bag it and put it in place of the Freezer burnt Ice cream.Then check on it every couple days shake off the ice ,weigh and place back in until   the weight doesn't change and Ice doesn't form.
At that point it should be dry. If it don't  check anymore than an air dry then Im sold.
I Have access to a freezer that is set to -17 or 20 don't remember. I might have to ge some others involved in my mad scientist testing.
Anybody every try this at home what were your outcomes ?



Dale

[sawdust]

In college I had a friend who freeze dried his ahh, herbs! yes. in the self defrosting freezer top of his fridge.
Said it worked great. How it would work for something of considerable mass I don't know. I would suspect that it would take a long time to get the ice to sublimate out of a block. I would think the moisture would migrate to the surface REALLY slow when cold.

[Sprucegum]

I have tried freezing green turning blanks and turning them while they're still frozen - with only moderate success. They were allowed to thaw and dry normally.

Firewood that freezes before its dry still has to dry after it thaws in the spring or it don't burn worth a darn.  :(

[oakiemac]

The freeze dry process requires that you not only freeze the product but put in a very high vacuum where the mositure is sucked out and on to a condensor. The big drug company that I work for has many large freeze dryers and I have often thought of converting them into kilns. But basically a vac kiln does this and you still would have all the expensive control issuses.