The Forestry Forum

General Forestry => Drying and Processing => Topic started by: 3244don on February 21, 2013, 04:28:25 PM

Title: Vacuum kiln
Post by: 3244don on February 21, 2013, 04:28:25 PM
Could someone give me the pros and cons of a vacuum kiln . Was going to build a dh kiln ,but came across a vacuum kiln at a good price.
Greatly appreciate any advise
Thank you.
Title: Re: Vacuum kiln
Post by: Den Socling on February 21, 2013, 04:34:14 PM
What do you call a good price? If you are looking at a WoodMizer VK2000 or 1000, beware.
Title: Re: Vacuum kiln
Post by: GeneWengert-WoodDoc on February 21, 2013, 04:57:53 PM
As a person who has run a WoodMizer vacuum kiln years ago, I would be very cautious about buying a used one, if that is what you are considering.  I know Den has tried to get them working; I know we always seem to have a maintenance item.  Plus, our final MC distribution was scattered.  For many customers, moisture variability can be a quality issue.  At times, it worked well; but at other times, not.

Did I ever tell the story about what happened when we were hauling the Wood Mizer kiln from Indy to VA?  In OH a guy in a pickup pulls along side us and starts beeping his horn. So, I pull over in our truck and the long silver box behind (4' x 4' x 20').  I thought maybe something fell off.  So, he walked up to the truck and said "Howdy boys."  I should have known then...he was so curious as to what we were hauling, that he pulled us over to find out.  Well, we were in a hurry indeed, so I told him we had frozen bodies inside and that we had to keep moving so they wouldn't thaw out.  His eyes grew and he let us go right away.  The person next to me could hardly stop laughing for the next hour.
Title: Re: Vacuum kiln
Post by: 3244don on February 26, 2013, 02:43:43 AM
Yes it's a woodmizer VK1000 and it is used price is $2000 .the say it works . What are the common problems with these units.
Thanks for the reply .
Title: Re: Vacuum kiln
Post by: scsmith42 on February 26, 2013, 10:09:10 AM
Quote from: GeneWengert-WoodDoc on February 21, 2013, 04:57:53 PM
As a person who has run a WoodMizer vacuum kiln years ago, I would be very cautious about buying a used one, if that is what you are considering.  I know Den has tried to get them working; I know we always seem to have a maintenance item.  Plus, our final MC distribution was scattered.  For many customers, moisture variability can be a quality issue.  At times, it worked well; but at other times, not.

Did I ever tell the story about what happened when we were hauling the Wood Mizer kiln from Indy to VA?  In OH a guy in a pickup pulls along side us and starts beeping his horn. So, I pull over in our truck and the long silver box behind (4' x 4' x 20').  I thought maybe something fell off.  So, he walked up to the truck and said "Howdy boys."  I should have known then...he was so curious as to what we were hauling, that he pulled us over to find out.  Well, we were in a hurry indeed, so I told him we had frozen bodies inside and that we had to keep moving so they wouldn't thaw out.  His eyes grew and he let us go right away.  The person next to me could hardly stop laughing for the next hour.

Good one!  It must be something about Ohio... about 10 years ago I was bringing back a set of draft horse shoeing stocks that I had bought from the Amish in Shipshewana, IN.  Going through Ohio I had a fellow pull up next to me at a stoplight and flag me over.  Same thing - he wanted to ask about the stocks. 
Title: Re: Vacuum kiln
Post by: mesquite buckeye on February 26, 2013, 10:47:26 AM
We bought a used VK1000 several years ago. We got it working....sort of. Dried a few thousand bf with difficulty. Problems with leakage, blankets melting. Then the compressor shot sparks out and welded itself solid one night. Haven't used it since. Can't recommend one. :( :o ::)
Title: Re: Vacuum kiln
Post by: Den Socling on February 26, 2013, 11:38:07 AM
Mesquite shot a bulls eye. A VK2000 is better but the electric blankets still make it nearly impossible to get an even MC.
Title: Re: Vacuum kiln
Post by: 3244don on February 26, 2013, 02:32:12 PM
Is it that the woodmizer has a poor design ,or are these vacuum kilns in general problematic . I herd they will dry much faster than DH if this is true does the fast drying also cause poor quality lumber .

Thanks for the info ,altho not what I wanted to here ,much better to learn this way  :P  than this way$$$.
Title: Re: Vacuum kiln
Post by: Den Socling on February 26, 2013, 02:59:20 PM
There are vacuum kilns and then there are vacuum kilns. WoodMizers had inherent problems. Same with every brand I ever worked on and I have serviced and changed the design of many. I decided to design and build my own kilns without all the problems. Are they fast? How about 12/4 Red Oak fresh of the saw down to 7% in 12 days with zero degrade. Vacuum kilns can knock your socks off. But they are expensive. People can't normally justify the cost if they are drying 4/4. Hard maple is the exception because it comes out so white.
Title: Re: Vacuum kiln
Post by: 3244don on February 26, 2013, 05:47:15 PM
Thanks den for the input . I'm always up to a good challenge , do you think the vk1000 would be a good base with some modifications to perfect it.
Do you market your VK design?
Title: Re: Vacuum kiln
Post by: jueston on February 26, 2013, 08:52:34 PM
Quote from: 3244don on February 26, 2013, 05:47:15 PM
Thanks den for the input . I'm always up to a good challenge , do you think the vk1000 would be a good base with some modifications to perfect it.
Do you market your VK design?

click on the link in his signiture, under his text....
Title: Re: Vacuum kiln
Post by: 3244don on February 27, 2013, 12:19:55 AM
I see Den does market his design .

Title: Re: Vacuum kiln
Post by: mesquite buckeye on February 27, 2013, 12:22:32 AM
Quote from: 3244don on February 27, 2013, 12:19:55 AM
I see Den does market his design .

I think it is much better. Smaller surface to seal, external loading, functional heating system. I'd like to see one of them running.
Title: Re: Vacuum kiln
Post by: Den Socling on February 27, 2013, 10:40:55 AM
I wouldn't recommend the VK1000 at any price. The "unfixable" problem is the electric blankets. The problem goes like this. If the temperature sensor (thermister) is placed next to a particularly wet piece of wood, it is cooled by evaporation. The control system reacts by turning on the heat. Now wood with lower MC continues to get hot. I've seen Red Oak come out looking like Ebony. If the thermister is next to dry wood, the control system sees the dry wood getting warm and backs off the heat. Now you have wet pockets where you had wetter wood. I have seen some good loads come out of VK2000's. And I have seen them run for years but you need to get to know them if you're going to get along with them. And they need modifications.
Title: Re: Vacuum kiln
Post by: 3244don on February 27, 2013, 10:32:09 PM
 Don,

Den what would the cost of your 1250 and 2400bf model be? Will your kilns dry a small load or do they need to be fully loaded ?
Title: Re: Vacuum kiln
Post by: 3244don on February 27, 2013, 10:59:31 PM
Also Den , what kind of temperatures are needed for the heating source applied to the wood. I was thinking I could use a boiler for the heat and I could fabricate tubing into a mat for in-between the wood.
Title: Re: Vacuum kiln
Post by: Den Socling on February 28, 2013, 10:15:31 AM
3244don, I don't like to use the Forum as a sales room. Please email me at dsocling@vacdry.com.