Vacuum dried lumber.

old3dogg · March 21, 2004, 01:57:25 AM

Hi All.
I ask this question a few weeks ago on another site but got very little info so Im going to ask it here.
Has anyone used vacuum dried lumber and if so what are your thoughts on the quality and how much stress if any have you seen?
Thanks.
Mike.

stevareno · March 22, 2004, 07:53:09 AM

Mike,
I kept checking your thread in the other forum for more responses. I would like to know if anyone uses vacuum dried lumber for flooring, treads, and trim? If stress is there, it will definatley show up coming off the gang rip. The whole concept of vacuum drying seams appealing but there simply isn't very many companies using vacuum compared to dh or conventional. If vacuum kilns offer faster drying times, less degrade, less space, and less energy, then it looks like vacuum kilns would be everywhere. Stress could be the factor, but then again pool cue makers often use vacuum dried maple for the shafts. They definatley can't have any stress. I too am looking for end users of vacuum dried wood.

Steve
Blakeman Hardwood Mouldings, Inc.

Den Socling · March 22, 2004, 09:05:46 AM

Hey guys,

The other day, a guy was telling me about charred wood out of his WoodMizer. I say, our kilns don't do that. He tells me about coming in and finding the thing down for thermister faults. I say, our kilns don't do that. He keeps telling me about problems and I keep saying that our kilns don't do that. The point is this: past experience doesn't count if a modern kiln doesn't have all the problems of old vac kilns.

Den

old3dogg · March 22, 2004, 11:42:56 AM

Steve.
Years ago people who sold vac kilns made a lot of crazy claims as to what their vac kilns could do.The vac kiln got a bad rap for that.Then there is the cost of buying the darn things and running them.I think that after you buy one and start using it I think you will see that the cost insnt really all that much compared to how much wood you can dry in a year compared to other dry kilns.
Stress was a problem for me but I was using square drying schedules on flooring blanks.I found out last week that was a mistake.My 8500BFT of 4/4 #2 comm. RO came out stress free with an average MC of 6.5% and very little degrade.
I know it took 11 days to dry but half the load was under water!We are going to cut up the 4/4 RO and glue them into pannels here soon.I will let everyone know how it turns out.
And listen to what Den says.The man knows.
Never thought I would say that! :D

On vac dried HM.I am told that HM dried in a vac kiln is harder than HM dried in any other kiln.Maybe that is the reason I dried over 70,000 base ball bat blanks last year?Or it may have something to do with the nice,white color?
Mike.

sawwood · March 22, 2004, 02:12:13 PM

Dennis do you know of any one in Mo Or Kan that has and
using a vacum kiln ? I would like to see one and git some
info from them.

Sawwood

Den Socling · March 22, 2004, 04:46:25 PM

Mike,

Remember when you were a hot-headed forktruck driver? I told your boss that I could teach you how to manage people and run the vac kilns. He believed me. That was smart, for both of us.

Sawwood,

We have kilns in PA and Washington state, nothing in between. I grabbed a really curly soft maple square during a visit to a customer last week. It's 4" square x 18" long and curly as the dickens. Do you want it? Free, of course.

Den

old3dogg · March 22, 2004, 04:50:59 PM

Den.
Im still a hot head but I have learned to control it!
I can still drive a fork truck like a mad man!
My boss still likes me too :D

stevareno · March 22, 2004, 05:10:17 PM

Mike,
I've never doubted Dennis's knowledge of vacuum kilns. We were a little skeptical as to how vacuum dried wood worked out for the type of products we're making. It sounds like you're doing some of the same type work. We've been purchasing mostly 1 common red oak from a local lumber yard. I've noticed a substantial amount of side bend in there lumber. SLR and you've lost 30% of the wood. Does vacuum dried lumber have alot of side bend or does that have more to do with how the wood is cut to begin with?

Steve

Den Socling · March 22, 2004, 05:15:42 PM

Steve,

If I put a board in that is bowed, it comes out bowed. If I put a board in that is flat, it comes out flat. Side bend would have to do with how it grew - how it was cut.

Den

old3dogg · March 22, 2004, 05:17:46 PM

Steve.
Im sure it has some to do with how it is cut.Im not sure.
The last load of 4/4 RO I dried had very little side bend.
I did see a little bit of cup but it was so little that it came out in the sander.
Im learning a lot about vac drying lumber right now.Im sure that I will have a lot more info in the next few weeks.
I have figured out how to dry RO stress free.This has been a problem with vac dried lumber.

stevareno · March 26, 2004, 09:37:28 AM

Mike,
I've finally convinced my business partner to just buy a kiln from Dennis rather than building one. I really don't think we can go wrong. Ironically I got a call yesterday from a company that wants us to supply them with 225,000 pcs of red oak that will finish at 1 1/8" thick and 1 5/8" wide x 60" long. They specifically want the MC to be between 15% and 25%. I think they are going to be bending the wood. How long will take me to get green red oak below 25%? Also, does your stress relieving techniques involve extra time in the kiln?

Thanks,
Steve

beenthere · March 26, 2004, 09:47:54 AM

Steve:That order for red oak seems to have a wide range in acceptable MC %. Aren't they concerned about holding it at a RH that will keep the wood from changing to a different MC and then warping when it changes?

Question. When ordering stock for bending, do they have any specs on the grain orientation, and the straightness of the grain? Just curious, as it would seem to be important.

Haven't "beenthere"

old3dogg · March 26, 2004, 10:30:34 AM

Steve.
Im going to base this response on the fact that I have only dried 1 full kiln charge of 4/4 RO.
I feel that the zero stress and even MC in the test load of 4/4 RO was the result of drying at a lower temp then I normally use in drying squares.
The load ran 11 days to get it to 6%MC.But remember.I had a leak in the kiln that flooded half the wood so this slowed things down a little.
Green to 25% I would guess would take 4 or 5 days in one of my vac kilns.Im sure Dens kilns are faster.

old3dogg · March 27, 2004, 06:42:45 AM

I just got back from the shop.I dried 5500BFT of 5/4 poplar in 99 hours.I saw a few cupped boards but zero side bend,no stress and no cracks.A quickie check on the MC said it was around 6%.I will pull the oven samples in the morning to get the true MC.

Den Socling · March 27, 2004, 10:54:32 AM

Would you believe that I'm currently drying Holly? Both 4/4 and 8/4. Some of the 8/4 is 10" wide and 80" long. That was one big shrub!

ElectricAl · March 27, 2004, 07:48:58 PM

Steve,

You were concerned with side bend earlier.

Basically, side bend is caused when one side of a board shrinks more than the other side. Look at the boards that concern you the most. Most likely they have a lot of straight grain or even quarter sawn on one side. The sap wood side of the board is what shrinks the most.

Side bend can be caused in the manufacturing process. Either on the saw or with the edger. If the sawyer saws one face of a log real deep then turns the log 90 degrees and saws several boards the Cathedral arch is not balanced.
It is best to have the Cathedral arch centered in the board.
If the arch is split down the middle each half will pull away from each other ( when green ).
An edger operator can also cause side bend in lumber by edging to upgrade. Say a 16" board has a clear strip 6" wide and the other 10" has a couple knots. Instead of selling the whole board for 1C, the operator can split the clear 6" off for a FAS board that is worth twice to 4 times the 1c price. Both boards will usually bend.

sawwood · March 27, 2004, 09:14:21 PM

Dennis how long would 10/4 white oak dry in the vacum kiln?
Is there any trouble with cracking or stress in the wood ?
I have a set of plans for a 4 poster bed and i need 4 X 4 oak
post. I am going to glue up two 10/4 pices to make the size
i need when i find a log that will give me the wood i need.
The post are 72" long but made in two pices. Also how would
you saw the log to git the best grain and not have warp in
the wood ?

Sawwood

old3dogg · March 28, 2004, 01:55:13 AM

Sawwood.
10/4 WO in a vac kiln.Im not saying it cant be done but it would be hard to do.
I have dried 4/4 WO with so,so results.
I will lwt some one else handle how you should saw them.I know nothing about sawing.

old3dogg · March 28, 2004, 02:01:24 AM

Jeff said it was ok to post this.
I had said earlier on a post about drying 70000 baseball bat blanks.
Here is the site if you want to see some really cool bats.

www.bwpbats.com.

Den Socling · March 28, 2004, 05:07:29 AM

Thank you ElectricAl. I knew that I would be over simplifying if I said the sapwood shrinks more in quartersawn boards.

Sawwood,
WO does not do well in a vac kiln. A special schedule has to be used. I may end up with a similar schedule for Red Beech so I may try some but there sure isn't any guarantee.

And Al is the guy who can better tell you how to cut what you want out of a log.

I keep thinking that I need to look for your shipping address. Would you just email it to me again?

Mike,

I'd like to get LouisvilleSlugger back on track to vac drying. Do you think Joe will stay in the bat business?

Den

Den Socling · March 28, 2004, 05:22:46 AM

BTW
I'm really dissapointed. I thought the Holly would bring a lot of cracks about me making it to Hollywood. :D :D :D

old3dogg · March 28, 2004, 06:33:16 AM

Hard to say about the bats right now Den.
I know we are giving Louisville a big head ache!

Den Socling · March 28, 2004, 06:38:34 AM

Mike,

They swear that you can't make a quality bat from a square. Their arguement sounds right. A square has a small chance of following the grain correctly. At least, that's what they tell me about making Ash bats.

Den

old3dogg · March 28, 2004, 06:48:04 AM

Cant make a bat from a square?How the heck would you make one?
Drying "rounds" in a vac kiln causes them to come out egged shaped.
Hope they aint glueing them.Remember the Sosa thing!
Glueing would be in againts NBL rules for sure.
Please note that BWP BATS does not carry Ash.

Den Socling · March 28, 2004, 07:16:32 AM

The Ash bats start as round billets. Yep. I can vac dry rounds and they will stay rounds.

old3dogg · March 28, 2004, 07:32:26 AM

like I said .We dont make ash bats.So i guess it really dont matter to me.
Most NBL hitters are using Hard Maple bats these days anyhow.
It is getting harder to find Ash trees big enough to make good bats anymore.The straight grain thing.
I dont watch a lot of baseball but I do hear of a lot of broken Ash bats durning a game.

beenthere · June 29, 2007, 05:29:26 PM

Here is a story on a local maple bat producer.

Maple bats

Seems the maple bats are more popular now that drying techniques have been improved.
I knew this fellow was in the wood business, but didn't know what his products were. I thought he was importing wood for sale. And maybe he is in addition to selling bat materials.

Den Socling · June 29, 2007, 10:12:24 PM

I had a young fellow doing carpentry in our new office. I gave him two of our vacuum dried, hard maple tiger stripe bats when he took an interest in them. He came back and bought five more.

Haven't seen him for awhile but he called the other day to say he hit a 450 foot home run. Everybody in the league wants our bats. He added that he will have plenty of time to work on our office next winter. ;)