Replies

1. 
   woodsmanplus | Jan 19, 2006 08:42pm | #1

   Hi Dennis,no that would not work as you need air flow to dry out green wood,or a kiln.

   Ken

1. 
   DennisS | Jan 20, 2006 09:18am | #2

   Greetings Ken -No, intuitively it doesn't sound like it's feasible, I would agree. What sparked the question was a comment from a buddy about some process he saw at a knife show where a fellow described impregnating his wood handle material with some sort of resin. But first the wood was subjected to a vacuum to draw out all the moisture.I'll have to look further into it .... could be my friend didn't understand what he heard.

1. 
   woodsmanplus | Jan 20, 2006 05:01pm | #3

   Morn Dennis I believe that he may have misunderstood them.You see with a vacume press all you do is draw out the air in the bag,then it sqeezes the wood together then stops.When you air dry or kiln dry the air has to circulate around the wood to get the moister out.Good luck.

   Ken

2. 
   mikegagne | Jan 22, 2006 08:19am | #8

   Woodsman, there is a possibility that it will work...sorta. Water evaporates at room temp in a vacuum. You will not be able to approach true vacuum (1 atmosphere or 27hg) but you can get close. There are kilns now that use warming plates that wood is stacked on with no air layer -plate-wood-plate-wood-plate-wood-etc. The plates have warm water circulating through them and the vacuum drawn dries the wood in hours rather than weeks. There is another take on this method with low frequency radiowaves and vacuum that will do 1000 bd/ft in 8 hours. So if you can increase the core temp of your wood, yeah it is possible. aloha, mike

1. 
   woodsmanplus | Jan 22, 2006 08:14pm | #9

   Hi Mike

   I'm sure you are right doing it that way,but the way the original question was put, I understood that was  he was going to put it in a regular vac press where there would not be any air circulation and that I don't believe would work.I could be wrong as they always say you are never to old to learn,but I always appreciate any new idea's or opinions.Thanks for the info. and have a great day.

   Ken

1. 
   mikegagne | Jan 22, 2006 10:53pm | #10

   Ken, air circulation is only required in a dehumidification type kiln. Water will leave the wood cells with the application of heat and vacuum. Atmospheric pressure is a hard thing to visualize and is the force at work in vacuum. When you draw the air out of a bag its not the suction that forces the bag down but rather the atmospheric pressure pushing from the outside. Wood in a vacuum kiln has the same force happening because the atmoshere is inside the wood cells and adding heat to the core of the wood piece accelerates its outmigration by breaking the cell walls. I've encclosed a link if you would like to read more about it. aloha, mikehttp://www.cfquesnel.com/nhi/Content/Section5/5_8.htm

2. 
   rocotoed | Jan 20, 2006 09:02pm | #4

   As I understand the citrus concentrate process, the juice is subjected to a vacuum, which lowers the boiling point of the juice down to a temperature that does not ruin the juice by heat. It 'boils', but at a lower temperature. Air flow does not seem to be a factor.

   Rocotoed

3. 
   QCInspector | Jan 20, 2006 10:30pm | #5

   Here is a link to The Forestry Forum.

   http://www.forestryforum.com/

   There is a section about drying wood, with a lot of info on vacuum kilns, that should satisfy your curiosity.

   The short answer is. Yes, you need a vacuum chamber. But you could make a small one, perhaps out of a painters pressure pot for example to dry bowls, if you wanted to experiment.

1. 
   DennisS | Jan 21, 2006 07:10am | #6

   Thanks for the link, OC. From the info on this site, though, there's a complex relationship between vacuum regulation, heat and so forth. I might try at some point taking a large piece of iron pipe to make my 'kiln' but for now it's a back-burner project.Thanks again.

4. 
   qtsam2 | Jan 22, 2006 02:06am | #7

   i used to dorestoration work, (water, fire, smoke, mold) and there was some interseting drying concepts. There was a system that used vacuum (negative pressure) with dehumidified air that significantly speed up the drying process. it would/could be modified of course but thetheory is still same. heres a link... http://www.injectidry.com/vpanel.htm