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

[Lynn Diel]

Joe
Thanks for the kind words.  Let me know if you need
more segments, I will gladly carve more if needed.  I
went ahead and sent a carving to Marnie for the
auction in Faribault.  I am working on one for Dennis
now.

In regards to the vaccuum kiln, I have gotten emails
for problably well over 25 people since the article
was written for the ezine saying that the built the
kiln and have good success. 
The only concerns they listed was the amount of water
that a tree can give up and trying to keep it out of
the vacuumm compressor.  We made an air dryer by
running a coil (25 foot 3/8" copper pipe)into a small
tank, all inside a small refigerator  and attaching
the output of that to the compressor.  We then
peridoically drained the tank of the excess moisture. 
Wrapping a heat tape around the tank in the winter
helped with the drying times.

In the wood that my friend and I dried (Red Oak), we
did not experience any warping, case hardening or
splitting.  We did over 1000 board foot of Oak for the
flooring and wainscoating.  There are quite a few
places out west (Montana and Idaho) that sent me
emails saying that there were commercial vacuum kilns
in there area.  The beauty of it is like Phill
indicated, the short drying time.  Physics is physics,
air alway moves from a high pressure (i.e. the wood) 
to a low pressure (i.e. the compressor). 

The shrinkage was about what you would expect for
regular kiln or solar drying for the Oak.  I have not
had the opportunity to do any carving wood other than
some Box Elder.  The Basswood in our area is just too
punky to use for small work.

Thanks
Lynn

--- Joe Dillett <jdillett at thecarvingshop.com> wrote:
> To make a DONATION to the Mailing List using PayPal
> OR regular mail, click this link:
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> 
> 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
> 
=== message truncated ===


=====
Lynn E. Diel
Columbia, MO
Website: http://carvers-creek.com