Anyone have experience in building and operating a small kiln for drying say
20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!

Greg

"Greg Lyman" wrote in message
. ..
Anyone have experience in building and operating a small kiln for drying
say 20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!


First advice - don't dry blanks unless you're talking about pen blanks. The
vagaries of thickness versus length of turning pieces are a tough nut to
crack. Rough turnings of things like containers - my word to encompass
plates, bowls and "forms" of all sorts - can benefit.

Second, all you need is something large enough to hold your materials which
is relatively air-tight. I used an old FM transmitter box back in the days
when I thought there was some sort of magic in drying wood. About the size
of a closet, made of the cheapest 1/4 plywood and spruce 1x3. Nice pallet
underneath, though.

Third, think humidistat. You'll get some "rule of thumb" advice from those
who just warmed the air with light bulbs inside old refrigerators, but it
isn't going to be anything you can duplicate with assurance. Water removal
by humidity reduction, and control of drying degrade by keeping a schedule
of RH reduction is the way things have been done for a long time. Best
place to start all this is at http://www.fpl.fs.fed.us/ where searches for
kiln construction and schedules will come up with all kinds of things.

Now, given that about a 1" thick bowl will reach equilibrium with its
surroundings in a couple months, tops, what's your hurry?

"Greg Lyman" wrote in message
. ..
Anyone have experience in building and operating a small kiln for drying
say
20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!

Greg



Check out this guys homemade kiln. The web address keeps changing, but I
have followed it for a couple of years. I am going to build one asap (I.E.
in the next three to five years :-). I have some of the matierial already
laid back in the barn.
Good Luck Lyndell
P.S. I strongly recommend you read William H. Brown's Conversion &
Seasoning of Wood and take a look at Ron Kent & Leif O. Thorvaldson's info
on using liquid dishwashing detergent to prevent cracking at
http://wwwronkent.com/rontech.html
I am interested in their technique.........but they say use kirkland LDD (
costco's house brand) but my closest costco is 2 hours away oneway plus $45
membership which will never get used. I also am exploring options. Word is
not yet in as to whether or not other brands of LDD will. I wore out google
and yahoo trying to establish who make kirkland and what it has in it. No
luck so far.



http://woodworking-woodworking.com/homekiln.html

Greg I built my Small Kiln about 5 years ago and it is in constant use and I
hope to add details to my hints and tips section of my Web Site in the
future.

I built it under my Bench by forming a box which I then lined with
Polystyrene Insulation faced with Hardboard covered in Aluminium Foil
[Kitchen Type will prevent moisture penetrating through wall of Kiln] made
sure that all joints are Vapour Sealed [Important] by using Good Quality
Waterproof Sealant Mastic.

Formed a small Duct across the top with an opening at each end, at one end I
fitted a small Fan [Ex-A/C Unit] and then used a 80 Watt Tube Heater
upstream of the Fan.

Fit a drain to allow Water to run away.

Door is a Insulated Plug Door that Bolts onto the Front of the Kiln again
lined with the Foil and a Rubber Gasket to form a Seal.

Fitted a Thermostat to switch the Heater on/off.

Start the process at 35°C for 1 month then 40°C for next month and then upto
45°C for final month.

Purists will say this is all wrong.

But I have now had something like 20 loads [upto 100 mixed Blanks] go
through the Kiln and I always have mixed Timber and mixed Sizes from Small
Blanks upto much larger bits at 14" x 14" x 4" and Logs.

I have dried and eventually Turned successfully:-

Oak
Cherry
Beech
Ash
Holly
Burr Oak
Laburnum
Yew
Beech
Spalted Beech
Walnut
Pear
Apple
Horse Chestnut
Eucalyptus
Elm
Maple
Plus others I cant remember.

I would say success rate is about 90/95% but what the heck it is nearly
always free wood.

It took me along time to get round to building this because all the Myth's
put about on drying timber, which I'm sure are true if you wish to Dry
Furniture Quality Planks by the Ton?

But when I got my first Free Tree [A Pear Tree of about 30ft³] I thought it
was about time I tried my luck and I have never regretted it.

Have ago it is not that difficult.

RVS
http://www.laymar-crafts.co.uk


"Greg Lyman" wrote in message
. ..
Anyone have experience in building and operating a small kiln for drying
say
20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!

Greg

Lyndell,
Thanks for the references. I don't have any problem with cracking, because
most of what I work with is English Walnut trunk wood and Black Walnut root
burl and I have learned how to prepare the wood properly for air drying
before and after roughing out. I do roughout a limited number of pieces,
but store most until I (or someone else) may decide what they want to be.

The only wood I have experience with and have found challenging to keep
together is Apricot. I do rough turn it and love it. I have tried the LDD
process on Apricot over a period of a couple of years and many pieces some
in the pot and some cured more conventionally. I have noticed no difference
in results with this wood. Results may vary with other types of wood, and I
know there is a group of believers out there in this process. So, it
undoubtedly has some merit, at least for them. I have also used PEG with
good results, but it is a long process and one that has consequences I
choose to avoid.

Our rule of thumb here in the desert (Albuquerque, NM) for air drying most
hardwoods to EMC is one inch per year plus a year. Tracking the change in
weight tends to confirm that this is a pretty good guide for this climate,
at least for the wood I get. I'm just interested in reducing this time to
reduce storage space. Thanks again for the references.

Greg

"Lyndell Thompson" wrote in message
ink.net...

Check out this guys homemade kiln. The web address keeps changing, but I
have followed it for a couple of years. I am going to build one asap (I.E.
in the next three to five years :-). I have some of the matierial already
laid back in the barn.
Good Luck Lyndell
P.S. I strongly recommend you read William H. Brown's Conversion &
Seasoning of Wood and take a look at Ron Kent & Leif O. Thorvaldson's
info
on using liquid dishwashing detergent to prevent cracking at
http://wwwronkent.com/rontech.html
I am interested in their technique.........but they say use kirkland LDD (
costco's house brand) but my closest costco is 2 hours away oneway plus
$45
membership which will never get used. I also am exploring options. Word is
not yet in as to whether or not other brands of LDD will. I wore out
google
and yahoo trying to establish who make kirkland and what it has in it. No
luck so far.



http://woodworking-woodworking.com/homekiln.html

Richard,
I was hoping to hear from a few folks with actual experience rather than
just those with opinions and thoughts. Thanks for this information and I'll
try to check your site in the future for additional tips and tricks.

Greg

"Richard Stapley" wrote in message
...
Greg I built my Small Kiln about 5 years ago and it is in constant use and
I
hope to add details to my hints and tips section of my Web Site in the
future.

"Greg Lyman" wrote in message
...
Our rule of thumb here in the desert (Albuquerque, NM) for air drying most
hardwoods to EMC is one inch per year plus a year. Tracking the change in
weight tends to confirm that this is a pretty good guide for this climate,
at least for the wood I get. I'm just interested in reducing this time to
reduce storage space. Thanks again for the references.

Well, that rule of thumb is for planks drying in outdoors New England. Also
assumes spring saw. Winter produces no drying. FPL experimental data shows
a summer's dry as adequate for most domestics. My rule of reality in
Michigan is to take 4/4 planks of local hardwoods (hard maple, cherry,
birch) sawed in June after the crops are in, sticker and stack for the
summer. Bring indoors in October when the nights get cold. Sticker, stack
in basement, and by January the stuff's at 6% by meter and oven dry.

Of course, you're not drying planks, and end grain dries at 10-15 times the
rate of face grain. Scientific and valid. That's the bad news. With solid
pieces short relative to their thickness, accommodating the drying schedule
to the end grain while waiting out the slower lateral (inverse square rule)
transfer from cell to cell takes special effort. It's the good news when
you speak of roughed containers with any depth, because no place is more
than an inch or so from open air through end grain.

In article ,
"Greg Lyman" wrote:

Anyone have experience in building and operating a small kiln for drying say
20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!

Greg, as an alternative, have you looked a microwaving the blanks (one
at a time). The reading I done suggests that it works well, the usual
warning of not rushing (ie setting the wood on firre).
I'm going to try it, once I have some wet wood.

--
--------------------------------------------------------
Personal e-mail is the n7bsn but at amsat.org
This posting address is a spam-trap and seldom read
RV and Camping FAQ can be found at
http://www.ralphandellen.us/rv

George,
And your point is...?
I am happy for you that you know how to dry 4/4 planks of local hardwoods in
Michigan. I'm also impressed that you know where the rule of thumb some of
us here use came from. And as I mentioned, it tends to correlate well with
observed weight loss in my circumstances. I should probably acknowledge
that the blanks I cut from English tend to range from 12 inches square by 4"
thick to 20" square x 4" thick. The Black Walnut burl varies in dimensions
up to 12" x 12" x 20" and I can cut it much larger if I choose to.

But if you re-read my original post, I was seeking information from those
with experience with small kilns on materials and operating conditions.
Perhaps the other information you have provided will be of interest to other
readers, but for me it is OT. Nevertheless, thanks for your effort.


"George" George@least wrote in message
...

"Greg Lyman" wrote in message
...
Our rule of thumb here in the desert (Albuquerque, NM) for air drying
most hardwoods to EMC is one inch per year plus a year. Tracking the
change in weight tends to confirm that this is a pretty good guide for
this climate, at least for the wood I get. I'm just interested in
reducing this time to reduce storage space. Thanks again for the
references.

Well, that rule of thumb is for planks drying in outdoors New England.
Also assumes spring saw. Winter produces no drying. FPL experimental
data shows a summer's dry as adequate for most domestics. My rule of
reality in Michigan is to take 4/4 planks of local hardwoods (hard maple,
cherry, birch) sawed in June after the crops are in, sticker and stack
for the summer. Bring indoors in October when the nights get cold.
Sticker, stack in basement, and by January the stuff's at 6% by meter and
oven dry.

Of course, you're not drying planks, and end grain dries at 10-15 times
the rate of face grain. Scientific and valid. That's the bad news. With
solid pieces short relative to their thickness, accommodating the drying
schedule to the end grain while waiting out the slower lateral (inverse
square rule) transfer from cell to cell takes special effort. It's the
good news when you speak of roughed containers with any depth, because no
place is more than an inch or so from open air through end grain.

Ralph,
Yes I have used my microwave for small pieces on occasions, but most of my
stuff is too large to fit in my kitchen unit. Thanks for your thoughts.

Greg

"Ralph E Lindberg" wrote in message
...
In article ,
"Greg Lyman" wrote:

Anyone have experience in building and operating a small kiln for drying
say
20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus
air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!

Greg, as an alternative, have you looked a microwaving the blanks (one
at a time). The reading I done suggests that it works well, the usual
warning of not rushing (ie setting the wood on firre).
I'm going to try it, once I have some wet wood.

--
--------------------------------------------------------
Personal e-mail is the n7bsn but at amsat.org
This posting address is a spam-trap and seldom read
RV and Camping FAQ can be found at
http://www.ralphandellen.us/rv

Lyndell Thompson wrote:
...
P.S. I strongly recommend you read William H. Brown's Conversion &
Seasoning of Wood and take a look at Ron Kent & Leif O. Thorvaldson's info
on using liquid dishwashing detergent to prevent cracking at
http://wwwronkent.com/rontech.html
I am interested in their technique.........but they say use kirkland LDD (
costco's house brand) but my closest costco is 2 hours away oneway plus $45
membership which will never get used. I also am exploring options. Word is
not yet in as to whether or not other brands of LDD will. I wore out google
and yahoo trying to establish who make kirkland and what it has in it. No
luck so far.


I've heard that Kirkland is mainly water. I use SunLight (stick with Yellow,
not Green) but have used other cheep store brands before. They all seem very
concentrated - since I have not tried Kirkland I can't compare, but they all
seem to work, at concentrations about 1 or 2 bottles for one 6-gallon bucket
(maybe 4 gallons of water).

mike

"Mike" wrote in message
ink.net...
Lyndell Thompson wrote:
...
P.S. I strongly recommend you read William H. Brown's Conversion &
Seasoning of Wood and take a look at Ron Kent & Leif O. Thorvaldson's
info
on using liquid dishwashing detergent to prevent cracking at
http://wwwronkent.com/rontech.html
I am interested in their technique.........but they say use kirkland LDD
(
costco's house brand) but my closest costco is 2 hours away oneway plus
$45
membership which will never get used. I also am exploring options. Word
is
not yet in as to whether or not other brands of LDD will. I wore out
google
and yahoo trying to establish who make kirkland and what it has in it. No
luck so far.


I've heard that Kirkland is mainly water. I use SunLight (stick with
Yellow, not Green) but have used other cheep store brands before. They
all seem very concentrated - since I have not tried Kirkland I can't
compare, but they all seem to work, at concentrations about 1 or 2 bottles
for one 6-gallon bucket (maybe 4 gallons of water).

mike

Thanks Mike I will give it a shot. You use all the other methods mentioned
I suppose? TIA
Lyndell

In article ,
"Greg Lyman" wrote:

Ralph,
Yes I have used my microwave for small pieces on occasions, but most of my
stuff is too large to fit in my kitchen unit. Thanks for your thoughts.

They must be large... my old kitchen unit (which is what I will use)
would handle a 20 by 12 by 8 inch block. But then it's a ~25 year old
unit and the old microwave's were much bigger then the current units

--
--------------------------------------------------------
Personal e-mail is the n7bsn but at amsat.org
This posting address is a spam-trap and seldom read
RV and Camping FAQ can be found at
http://www.ralphandellen.us/rv

In article . net,
Mike wrote:

Lyndell Thompson wrote:
...

I've heard that Kirkland is mainly water. I use SunLight (stick with Yellow,
not Green) but have used other cheep store brands before.

I've used both, and there is also no difference. Kirkland tends to
separate more, but a good shake takes care of that

--
--------------------------------------------------------
Personal e-mail is the n7bsn but at amsat.org
This posting address is a spam-trap and seldom read
RV and Camping FAQ can be found at
http://www.ralphandellen.us/rv

In article . net,
"Lyndell Thompson" wrote:

they say use kirkland LDD (
costco's house brand) but my closest costco is 2 hours away oneway plus $45
membership which will never get used. I also am exploring options. Word is
not yet in as to whether or not other brands of LDD will. I wore out google
and yahoo trying to establish who make kirkland and what it has in it. No
luck so far.

As one who has made it a tenet his personal religion to avoid Costco,
Home Depot, and other behemoths of retail, I have had very good success
with Sunlight brand -- yellow as Mike recommended.

:-o

I just pulled a small Filbert (Hazelnut) bowl out of the "soup" after
forgetting about it since January of '03. Wiped it off and set it on the
shelf to "off-gas". The thing certainly feels dry - weight wise - after
only a couple weeks. It also doesn't appear to have distorted anywhere
near as much as the other Filbert bowls I made back in '03 from the same
wood haul. I lost probably 80-90% of the other pieces due to major
cracking while brown bagging them for 6 months or so in my basement.

(I know how to brown bag and usually have excellent results with the
other woods I use like Black Walnut, Big Leaf Maple and the like.)

BTW, that bright sunny yellow Sunlight dish soap is now a motor oil
colored witches brew.

--
Owen Lowe

Northwest Woodturners
Pacific Northwest Woodturning Guild
___
Tips fer Turnin': Place a sign, easily seen as you switch on your lathe, warning you to remove any and all rings from your fingers. Called degloving, extended hardware can grab your ring and rip it off your finger. A pic for the strong of stomach: www.itim.nsw.gov.au/go/objectid/2A3AC703-1321-1C29-70B067DC88E16BFC/index.cfm

Besides, rings can easily mar the surface of a turning as you check for finished smoothness.

In article ,
"Greg Lyman" wrote:

The only wood I have experience with and have found challenging to keep
together is Apricot. I do rough turn it and love it. I have tried the LDD
process on Apricot over a period of a couple of years and many pieces some
in the pot and some cured more conventionally.

I've not turned apricot but love it whenever I get ahold of some plum.
About the only way I've been successful with plum is by boiling. Some
folks have commented that the color of their plum has diminished
markedly over a short time, but my boiled pieces appear as gorgeous as
they did years ago. (They are in an interior bookcase and not subject to
direct sunlight, so maybe that is a major factor compared to the folks
offering their comments. I believe some of it tho is a factor of
boiling.)

AAMOF, here's a pic of one of them:
http://66.116.216.38/images/Lowe5.jpg

Put in a pot of cold tap water, bring the heat up, let sit in a roiling
boil for at least an hour, cut the heat and allow to cool in the water.
Then wipe dry and air dry for an hour or so and paper bag for several
weeks to two months. Haven't lost one yet doing it this way.

--
Owen Lowe

Northwest Woodturners
Pacific Northwest Woodturning Guild
___
Tips fer Turnin': Place a sign, easily seen as you switch on your lathe, warning you to remove any and all rings from your fingers. Called degloving, extended hardware can grab your ring and rip it off your finger. A pic for the strong of stomach: www.itim.nsw.gov.au/go/objectid/2A3AC703-1321-1C29-70B067DC88E16BFC/index.cfm

Besides, rings can easily mar the surface of a turning as you check for finished smoothness.

"Greg Lyman" wrote in message
...
George,
And your point is...?

That if you start with poor information, your outcome is likely to be the
same. The inch per year is folklore, and your invocation of it indicates
that you haven't really done much information-gathering about drying wood.

If you don't understand what's happening as wood dries, then any kiln is
just a magic hat, and you may spend much frustrating time pursuing the
combination that finally reveals the rabbit.

George, George, George,
Once again I think you have missed the point. My original post was seeking
information from anyone with experience in "building and operating" a small
kiln for drying turning blanks. If you have any, it is not apparent from
your posts. So why did you even chime in? I don't doubt that you are quite
an expert when it comes to wood - an expert being someone who doesn't know
what he doesn't know and is afraid to learn because it would threaten his
self image. Having said that, however, I want to encourage you to continue
posting your little rants, because it is reassuring to me to know that every
minute you spend typing is one less minute you have to be hurting wood in
your shop or studio assuming you have one.

Have a great life, George, and by all means continue to enlighten us with
your prophetic knowledge! Type on George!

Greg


"George" George@least wrote in message
...

"Greg Lyman" wrote in message
...
George,
And your point is...?

That if you start with poor information, your outcome is likely to be the
same. The inch per year is folklore, and your invocation of it indicates
that you haven't really done much information-gathering about drying wood.

If you don't understand what's happening as wood dries, then any kiln is
just a magic hat, and you may spend much frustrating time pursuing the
combination that finally reveals the rabbit.

Thanks, Owen. Next time I get some Apricot, I try this.

Greg


"Owen Lowe" wrote in message
news
In article ,
"Greg Lyman" wrote:

The only wood I have experience with and have found challenging to keep
together is Apricot. I do rough turn it and love it. I have tried the
LDD
process on Apricot over a period of a couple of years and many pieces
some
in the pot and some cured more conventionally.

I've not turned apricot but love it whenever I get ahold of some plum.
About the only way I've been successful with plum is by boiling. Some
folks have commented that the color of their plum has diminished
markedly over a short time, but my boiled pieces appear as gorgeous as
they did years ago. (They are in an interior bookcase and not subject to
direct sunlight, so maybe that is a major factor compared to the folks
offering their comments. I believe some of it tho is a factor of
boiling.)

AAMOF, here's a pic of one of them:
http://66.116.216.38/images/Lowe5.jpg

Put in a pot of cold tap water, bring the heat up, let sit in a roiling
boil for at least an hour, cut the heat and allow to cool in the water.
Then wipe dry and air dry for an hour or so and paper bag for several
weeks to two months. Haven't lost one yet doing it this way.

--
Owen Lowe

Northwest Woodturners
Pacific Northwest Woodturning Guild
___
Tips fer Turnin': Place a sign, easily seen as you switch on your lathe,
warning you to remove any and all rings from your fingers. Called
degloving, extended hardware can grab your ring and rip it off your
finger. A pic for the strong of stomach:
www.itim.nsw.gov.au/go/objectid/2A3AC703-1321-1C29-70B067DC88E16BFC/index.cfm

Besides, rings can easily mar the surface of a turning as you check for
finished smoothness.

"Greg Lyman" wrote in message
. ..
Anyone have experience in building and operating a small kiln for drying
say 20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!

Greg



Greg,
Here's an idea used by a club member Joe Ruminski. I'll try to remember it
correctly. At least it's about your question.

Build a rectangular plywood box, well sealed and insulated with that hard
foam stuff at Home Depot, with a long side facing you and hinged to open
upward for loading. Include shelves that allow air circulation. Install a
dehumidifier (mine from Grainger's - BASEMENT variety) with drain tube to a
bucket outside (to monitor rate of drying). It's plugged into a simple
programmable timer (to control rate of dehumidification better than just the
control on some dehumidifiers). He even uses a small squirrel-cage fan for
interior circulation.

He's developed a plan for timing it's operation; something like all the time
at first, then so many minutes per day for X days. He puts rough turned
bowls in and then uses a moisture meter to verify progress, and then finish
turns.

Joe's a commercial turner and a great guy, not a BS artist. This system
works well for him to accelerate production. While I haven't all the
specifics it should give you a start point. To me, the keys are the bucket
measuring the rate of moisture removal without intrusion and a dehumidifier
instead of just heat. I just ordered one of the moisture meters from Harbor
Freight. Be sure to use the "online catalog" since the price becomes 19.95
vs 29.95 simply online.

TomNie

Tom Nie wrote:
Build a rectangular plywood box, well sealed and insulated with that hard
foam stuff at Home Depot, with a long side facing you and hinged to open
upward for loading. Include shelves that allow air circulation. Install a
dehumidifier (mine from Grainger's - BASEMENT variety) with drain tube to a
bucket outside (to monitor rate of drying). It's plugged into a simple
programmable timer (to control rate of dehumidification better than just the
control on some dehumidifiers). He even uses a small squirrel-cage fan for
interior circulation.

I use a dehumidifier in my drying room, but only in summer when the
natural humidity is high in my climate. There are two reasons for this.

First, the relative humidity I am aiming for (35%-40%) is easily
achieved in winter by modest heating. I just checked and it was down to
31% at only 21C/70F, so I turned the heat down.

Second, my dehumidifier has a chart of humidity-temperature conditions
below which it should not be operated since it may frost up and not
remove water. I also suspect that close to these conditions it will be
operating inefficiently.

To achieve 40% RH, the recommended minimum temperature is 27C / 80F.
Easily done in summer, but in winter will rquire quite a bit of heat.

Having said all that, I am working in a whole room, 7'x8', with two
outside walls, so situation is somewhat different. I also air dry wood
before it goes into this room, and have a continuous in/out process
rather than the batch process suggested. But would encourage anyone
setting up a drying system to consider how they plan to operate it, and
whether the RH can best be controlled by applying heat or removing moisture.

--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
http://chipshop.blogspot.com - a blog for my customers
http://www.seafoamwoodturning.com/TheToolrest/ - a blog for woodturners

Derek,
When the dehumidifier is enclosed the heat it generates as a part of the
dehumidification process is recirculated. That might answer one of your
thoughts. Remember, only the drain hose and power cord are outside.

Also, I emphasized a basement model because it's specifically designed to
continue to dehumidify at lower temps. And, here in central North Carolina,
31% is exactly what I have now in my living quarters but wouldn't want to
circulate the airborne dust of my workshop through my regular HVAC. Outside
it's 66% at the moment. We may not be tropical but this is not a dry area.

TomNie

"Derek Andrews" wrote in message
...
Tom Nie wrote:
Build a rectangular plywood box, well sealed and insulated with that hard
foam stuff at Home Depot, with a long side facing you and hinged to open
upward for loading. Include shelves that allow air circulation. Install a
dehumidifier (mine from Grainger's - BASEMENT variety) with drain tube to
a bucket outside (to monitor rate of drying). It's plugged into a simple
programmable timer (to control rate of dehumidification better than just
the control on some dehumidifiers). He even uses a small squirrel-cage
fan for interior circulation.

I use a dehumidifier in my drying room, but only in summer when the
natural humidity is high in my climate. There are two reasons for this.

First, the relative humidity I am aiming for (35%-40%) is easily achieved
in winter by modest heating. I just checked and it was down to 31% at only
21C/70F, so I turned the heat down.

Second, my dehumidifier has a chart of humidity-temperature conditions
below which it should not be operated since it may frost up and not remove
water. I also suspect that close to these conditions it will be operating
inefficiently.

To achieve 40% RH, the recommended minimum temperature is 27C / 80F.
Easily done in summer, but in winter will rquire quite a bit of heat.

Having said all that, I am working in a whole room, 7'x8', with two
outside walls, so situation is somewhat different. I also air dry wood
before it goes into this room, and have a continuous in/out process rather
than the batch process suggested. But would encourage anyone setting up a
drying system to consider how they plan to operate it, and whether the RH
can best be controlled by applying heat or removing moisture.

--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
http://chipshop.blogspot.com - a blog for my customers
http://www.seafoamwoodturning.com/TheToolrest/ - a blog for woodturners

Many thanks to those of you who responded on topic. I am continuing to
explore design and operating options including time, temperature, relative
humidity, and pressure (absolute). We'll see what develops from the
research. Ultimately the design will be simple and operating conditions
controlled automatically. I may not get around to building it until this
summer, but I will post results once it is out of the prototype stage. In
time, I will also try to develop some useful correlations for a few woods
other than English Walnut and Black Walnut burl - the majority of the green
wood I use.

Greg

"Greg Lyman" wrote in message
. ..
Anyone have experience in building and operating a small kiln for drying
say 20 to 50 turning blanks at a time. I am primarily interested in
construction materials and operating information - not how kiln versus air
drying affects properties of the wood. Primary wood I am interested in
drying is English Walnut. Thanks!

Greg

Tom Nie wrote:
Derek,
When the dehumidifier is enclosed the heat it generates as a part of the
dehumidification process is recirculated. That might answer one of your
thoughts. Remember, only the drain hose and power cord are outside.

That will work fine in a small space, but may not be the most efficient
way of providing heat.

As an aside, there is large commercial kiln near me which is run solely
on a compressor. That generates both air flow through the stecked boards
and gradually brings the temperature up.

Also, I emphasized a basement model because it's specifically designed to
continue to dehumidify at lower temps.

Thanks. That's good to know and will bear that in mind if I ever need to
buy another. When I bought mine I thought a dehumidier was a
dehumidifier. I didn't find out about the limitations until I opened the
box

--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
http://chipshop.blogspot.com - a blog for my customers
http://www.seafoamwoodturning.com/TheToolrest/ - a blog for woodturners

"Derek Andrews" wrote in message
...
Tom Nie wrote:
Derek,
When the dehumidifier is enclosed the heat it generates as a part of the
dehumidification process is recirculated. That might answer one of your
thoughts. Remember, only the drain hose and power cord are outside.

That will work fine in a small space, but may not be the most efficient
way of providing heat.


Sort of neat, if you think of it. The heat is produced as a by-product of
the refrigeration system which cools the air enclosed in the same box to
condense the moisture . I think I'd plumb things differently.

Perhaps that's why the commercial folks exhaust the wet air, replacing with
the dryer outside air which, as we know, is free. If they warm the outside
air on its way in, they lower its RH to speed drying, and the AH to allow
more moisture to be carried away.

Actually, George, it's like the recirculating setting on your car AC instead
of the outside air setting. That is, it keeps drying and redrying the same
air with only the liquid being piped outside. And so on, and so on. Since
it's an enclosed system it's highly efficient and the size of the box can
pretty well be what you want it to be.

A dehumidifier doesn't exhaust cool air like an AC. Unlike the car's
evaporator air discharging separately, the air passes over the condenser so
it's actually warm air discharged. The slow fan speed allows more time for
the humid air to spend around the evaporator which also helps dehumidify
without cooling the air as much. I know around here if you brought in
outside air you'd be forever trying to achieve the differential or, another
way of saying it, is that you'd be buying a lot more than a $300
dehumidifier (and in such a small area you could buy even cheaper and still
be a Basement Model).

The squirrel cage fan is just additional air movement to prevent any pockets
of disparity.

And if the box was only heated then you'd have to have outside air of less
humidity to replace the "humid" air inside. The key here is a "change of
state" which is what dehumidifiers and AC's achieve.

I'm sure there're engineers who can figure the cost efficiencies but it sure
seems like a slick way of drying faster than air; less messy than some
solutions; capable of handling a fair volume; with simple fast access for
inspection and testing (no bags or surrounding materials). All done for
maybe $200 to $400 one-time for store bought materials.

I'm still building my shop so my hands on experience is nil. However, I'm
building one under the porch next to the shop since I believe Joe to be the
kind of man to know what he's doing.

TomNie - top posting as usual

"George" George@least wrote in message
...

"Derek Andrews" wrote in
message ...
Tom Nie wrote:
Derek,
When the dehumidifier is enclosed the heat it generates as a part of the
dehumidification process is recirculated. That might answer one of your
thoughts. Remember, only the drain hose and power cord are outside.

That will work fine in a small space, but may not be the most efficient
way of providing heat.


Sort of neat, if you think of it. The heat is produced as a by-product of
the refrigeration system which cools the air enclosed in the same box to
condense the moisture . I think I'd plumb things differently.

Perhaps that's why the commercial folks exhaust the wet air, replacing
with the dryer outside air which, as we know, is free. If they warm the
outside air on its way in, they lower its RH to speed drying, and the AH
to allow more moisture to be carried away.

"Tom Nie" wrote in message
...
Actually, George, it's like the recirculating setting on your car AC
instead of the outside air setting. That is, it keeps drying and redrying
the same air with only the liquid being piped outside. And so on, and so
on. Since it's an enclosed system it's highly efficient and the size of
the box can pretty well be what you want it to be.


Was, of course, talking about the heat, not the air or moisture. Since the
condensation requires cooling the coils, makes not a lot of sense to heat
the air passing over them.

A dehumidifier doesn't exhaust cool air like an AC. Unlike the car's
evaporator air discharging separately, the air passes over the condenser
so it's actually warm air discharged. The slow fan speed allows more time
for the humid air to spend around the evaporator which also helps
dehumidify without cooling the air as much. I know around here if you
brought in outside air you'd be forever trying to achieve the differential
or, another way of saying it, is that you'd be buying a lot more than a
$300 dehumidifier (and in such a small area you could buy even cheaper and
still be a Basement Model).


If air runs out over the cold coils, it's cooled, so I am not sure what
you're trying to say. The "basement" dehumidifiers have a defrost cycle
built in them where just the fan runs to pull warm air over those coils and
thaw them. Allows their use in cooler or more humid areas. You can
interrupt the power altogether with timers on a cheaper model, but you
sacrifice the humidistat control.

The squirrel cage fan is just additional air movement to prevent any
pockets of disparity.

And if the box was only heated then you'd have to have outside air of less
humidity to replace the "humid" air inside. The key here is a "change of
state" which is what dehumidifiers and AC's achieve.

If the wood is giving off moisture, all outside air is of less humidity than
inside air. The key here is the exchange of wetter for dryer, so that the
process can continue.


I'm sure there're engineers who can figure the cost efficiencies but it
sure seems like a slick way of drying faster than air; less messy than
some solutions; capable of handling a fair volume; with simple fast access
for inspection and testing (no bags or surrounding materials). All done
for maybe $200 to $400 one-time for store bought materials.


There is no way of drying faster than air can absorb moisture. That's
because it's the air which dilutes and carries the water away. Whether that
air is dehumidified at great cost and the water drained away, or exhausted
and replaced by air of lower humidity makes no difference to the wood.
That's why a fifty buck humidistat and two muffin fans, with an option on a
light bulb or two makes a dandy kiln.


I'm still building my shop so my hands on experience is nil. However, I'm
building one under the porch next to the shop since I believe Joe to be
the kind of man to know what he's doing.


Well, vicarious experience shows the way to do things if you have somewhere
to get rid of some somewhat smelly air. It's the way the big boys do it.
Exhaust air of relative humidity higher than desired for the point in the
cycle and replace it with dry air. If what you're hinting at in that one
puzzling passage about your location is that you have a high ambient
relative humidity, you can warm that air, which drops the relative humidity,
prior to bringing it into the kiln near the end of the cycle as well. That
way you can dry the wood below the EMC it would naturally assume sitting
outside the kiln environment.

Of course, it'll start to gain that moisture back as soon as you take it
out, anyway, so I'm not sure what you gain by doing so.

Ralph, Where are you getting the SunLight LDD. I have seen it before.....and
was sure I could find it but so far I have not. I am in the southern part of
Indiana. I am a refrigeration technician and spend a lot of time in stores
G but havn't found it yet.
Thanks in advance.
Lyndell



"Ralph E Lindberg" wrote in message
...
In article . net,
Mike wrote:

Lyndell Thompson wrote:
..

I've heard that Kirkland is mainly water. I use SunLight (stick with
Yellow,
not Green) but have used other cheep store brands before.

I've used both, and there is also no difference. Kirkland tends to
separate more, but a good shake takes care of that

--
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