[Woodcarver] Thank you Lynn. (was drying a 10" log)

Tue Jun 22 09:24:36 EDT 2004

Hi Lynn,

Thank you for the 4 cane segments you sent for Marnie. They arrived at the
post office safely. I love them. Very nicely carved and painted. They will
make wonderful additions to any cane. I'm getting almost enough to put the
first one together.

I also read your article again on building the vacuum kiln. It is a great
concept. I have one question. Have you or anyone else on the List
experienced any ill effects from this fast drying process? I'm thinking that
the wood doesn't have time to naturally shrink as the moisture is drawn out
and the density of the wood changes. Has anyone ever measured shrinkage
before and after the vacuum kiln? This compared with air-dried piece
shrinkage would give the difference in density. I believe density relates to
strength and how small cross sections of grain would be more likely to chip
off.

I'm almost tempted to build a vacuum kiln just to compare shrinkage and
density differences.

Joe Dillett
The Carving Shop
645 E. LaSalle St. Suite 3
Somonauk, IL. 60552
(815) 498-9290 phone
(815) 498-9249 fax
http://www.thecarvingshop.com
jdillett at thecarvingshop.com
http://www.carvingmagazine.com Carving Magazine web site and Readers Forum

**************************************************

----- Original Message ----- 
From: "Lynn Diel" <carvers_creek at yahoo.com>
To: "[Woodcarver]" <woodcarver at six.pairlist.net>
Sent: Tuesday, June 22, 2004 6:49 AM
Subject: Re: [Woodcarver] drying a 10" log

> To make a DONATION to the Mailing List using PayPal OR regular mail, click
this link: http://wwwoodcarver.com/WWWList/WWWList.html
>
> Ray
> To follow up on what Phill wrote, there is an article
> in the woodcarver ezine located at the following url;
> http://carverscompanion.com/Ezine/Vol2Issue4/Vol2Issue4TOC.html
> it talks about how you can build your own vacuum kiln.
> If you have any questions, let me know.
> Good luck Lynn
>
>
> --- Phill Pittman <phill at masterwerkes.com> wrote:
> > To make a DONATION to the Mailing List using PayPal
> > OR regular mail, click this link:
> > http://wwwoodcarver.com/WWWList/WWWList.html
> >
> > Hi Ray.  there is no simple way ( if drying the wood
> > ) to prevent splitting
> > without involving an environment with a partial
> > vacuum in it. We carve large
> > ( and small )green wood regularly and anything you
> > do that accelerates air
> > flow past it will cause cracking where the air
> > crosses the surface. (
> > aromatic cedar and a few imported oil laden woods
> > are some of the only
> > exception ). drilling holes will help if naturally
> > drying, but hurt if you
> > force air with the vacuum.
> >
> >  Making a vacuum chamber for a log is not as
> > difficult as it seems.Large
> > schedule 80 pvc ( the kind you will see around
> > public sewer projects ) will
> > work in a pinch, but if it is something you might
> > want to repeat later, a
> > section of iron pipe that the log will fit inside of
> > will do it. I got mine
> > from a local scrap metal place and had enough left
> > over for the " shop"
> > smoker/bar-b-q). Welding a plate over one end and
> > fashioning a removable
> > plate for the other end will work for the vacuum.
> > remember a vacuum is self
> > sealing and getting an airtight seal is more
> > important than fasteners or
> > bolts etc. It is also much easier to do. If your
> > project allows, remove any
> > surface of the wood that you can before drying, but
> > keep the fresh cuts wet
> > until you are putting it in the tube.
> > The fluids inside the log will gasify at near room
> > temperature in a 25"
> > vacuum. If you are lucky enough to score a good
> > vacuum pump, it will work at
> > room temperature.
> > As I am sure you know, wood splits when drying as
> > air removes moisture from
> > one location more than the rest. Usually this is the
> > exterior of the wood.
> > The resulting shrinkage from the loss of moisture is
> > unable to occur because
> > the interior wood still contains it moisture and
> > it's original size. When
> > using a true ( partial) vacuum to remove moisture,
> > the wood is not drying
> > from the outside in. As the pressure drops the
> > moisture, in a pretty uniform
> > sequence, aspirates the moisture into gas which
> > escapes the wood.
> >
> > This process is accelerated by heated wood. This is
> > the only difficult part.
> > There are expensive heating blanket made
> > specifically for vacuum kilns, but
> > they represent a significant invest in the make-up
> > of the chamber and the
> > heater itself. Any heat source has to be contact
> > only. Remember that a
> > vacuum insulates and normal convection does not
> > convey heat. Radiant heat
> > ( light in various forms ) heats only the exterior
> > and may cause uneven
> > drying. All we do is pre-heat it just like an oven
> > and try to get the vacuum
> > pulled down while there is still some heat in the
> > log. It will not cool down
> > much after the vacuum has removed the air.( think
> > about a thermos jug ) When
> > you heat it up you have to let it remain heated for
> > several hours to insure
> > that the interior of the log is the same temperature
> > as the exterior.
> >
> > You can get serviceable vacuum pumps off eBay for
> > $50 bucks if you are only
> > going to do it a time or two. The actual original
> > purpose of the vacuum pump
> > is inconsequential, only that it will pull a 22" or
> > better vacuum and run as
> > required for several days. the drying time will
> > depend on species, size, and
> > too many other factors to name. But the thumbnail
> > measuring method of choice
> > is to weigh your entire contraption. If your log is
> > of any size there will
> > be a drastic weight change ( usually a hundred or
> > two pounds) as it loses
> > moisture. When your assembly stops losing weight,
> > your done. At lest as far
> > as you can go without mortgaging the house.
> > Commercial kilns dry 8/4 white
> > oak for about 48 hours at 22" vacuum. Almost zero
> > checking /splitting and a
> > very uniform 6% moisture content.
> >
> > Woodmizer ( the same folks that make the saw mill)
> > used to sell some light
> > commercial vacuum kilns and are a great source for
> > technical info.
> >
> > All that being said, if you can find it, aromatic
> > cedar is real forgiving
> > the same day it is cut. We are in the middle of a
> > 2000 piece run of
> > "spirits" about 20" tall and 4" thick through the
> > nose area. We produce
> > about 50 a day out of aromatic cedar that is often
> > sawmilled on the same day
> > we mount it on the machines. We have an occasional
> > loss from internal
> > checks, but they seldom to appear to be from drying
> > in the wind of the
> > router motors, more like internal stress cracks with
> > some resins visible.
> >
> > I also have a friend that is about to try Vacuum
> > bagging a log just like you
> > were gluing laminate and putting to in a hot box in
> > the sun. I will be
> > curious to see how it comes out. In theory it should
> > work the same.
> >
> > And as said in the previous post, if you can stress
> > relive the back, that is
> > always going to give you a more long term stable
> > product.
> >
> > Sorry for the oration, I get asked this from time to
> > time and just hadn't
> > had a forum to share it on.
> >
> > Best of luck and let us know how it goes.
> >
> > Phill Pittman
> > digicarve at verizon.net
> > www.masterwerkes.com
> >
> > ----- Original Message ----- 
> > From: "RAY MIGHELLS" <raymighells at earthlink.net>
> > To: "[Woodcarver]" <woodcarver at six.pairlist.net>
> > Sent: Monday, June 21, 2004 6:31 PM
> > Subject: Re: [Woodcarver] drying a 10" log
> >
> >
> > > To make a DONATION to the Mailing List using
> > PayPal OR regular mail, click
> > this link:
> > http://wwwoodcarver.com/WWWList/WWWList.html
> > >
> > > Hi Ray;  What kind of wood?   How dry is it now?
> > What are you going to
> > > carve on it?  Many woods are easier to carve
> > "green".  Keep it wet with a
> > > spritz bottle of water, cover it with something
> > wet/damp, and wrap in
> > > plastic when not carving.  Depending on the depth
> > of your carving,  you
> > may
> > > have to hollow it out from the back.  There's a
> > lot of grain tensions in
> > > different degrees of stress,  so even if it is dry
> > when you are finished,
> > > the seasonal changes can have distastrous effects
> > if the tensions are not
> > > somewhat compensated by relieving the back.  A PEG
> > treatment will help
> > some.
> > > Happy carving and good luck  Ray Mighells  6760 Rt
> > 417 Killbuck NY 716 945
> > > 0098 Please view my work at:
> > http://www.picturetrail.com/razaxnstuff
> > > ----- Original Message ----- 
> > > From: "Fishley, Ray (IS - Municipal Engineering)"
> > > <Ray.Fishley at City.Saskatoon.Sk.CA>
> > > To: <woodcarver at six.pairlist.net>
> > > Sent: Monday, June 21, 2004 5:27 PM
> > > Subject: [Woodcarver] drying a 10" log
> > >
> > >
> > > > To make a DONATION to the Mailing List using
> > PayPal OR regular mail,
> > click
> > > this link:
> > http://wwwoodcarver.com/WWWList/WWWList.html
> > > >
> > > > I would like to carve a 10" x 12 foot log.
> > > > I am looking for away to dry it so that it does
> > not crack or check.
> > > > I was thinking of drilling a 1" hole through the
> > center of it and
> > > connecting
> > > > a vacuum to it for a few weeks.
> >
> === message truncated ===
>
>
> =====
> Lynn E. Diel
> Columbia, MO
> Website: http://carvers-creek.com
> _______________________________________________
> Woodcarver mailing list
> Woodcarver at six.pairlist.net
> http://six.pairlist.net/mailman/listinfo/woodcarver