First, let me say the biggest THANK YOU Scott!! permitted by the software!
Scott was the first ever Guest Speaker on our Thursday night chats.
Scott answered questions from logs, veneers, sealing, ponds and even how to build the Guinness Book of World Records most monstrous workbench!
What follows is a lightly edited copy of last nights chat.
Its worth a read, there are really a ton of gems that Scott shared with us.
Enjoy!
Jim
PART 1
[froglips] 7:52 pm: ..... and on that note........
[froglips] 7:53 pm: Thanks for coming out tonight!
[froglips] 7:53 pm: We are kicking off our 2010 Guest Speaker Series with the
one and only Scott Smith
[MarkE] 7:53 pm: :clap:
[froglips] 7:54 pm: Scott, if you'd like to give a quick overview on your
amazing operations, then we can dive into the posted questions, then open the
floor for more.
[froglips] 7:54 pm:
http://www.ncwoodworker.net/forums/f23/new-member-chat-guest-speaker-series-feat
uring-scott-smith-34147/
[scsmith42] 7:54 pm: Howdy all! I'm glad to be here tonight.
[scsmith42] 7:54 pm: I operate a sawmill and dry kiln outside of Raleigh.
[scsmith42] 7:55 pm: Additionally, I have a nice 5,200 sq ft shop that includes
some cool production equipment. Namely a 25" jointer/planer, 37" wide belt
sander, 16" horizontal resaw, an old Mattison 202 straight line rip saw, and a
Baker 4 head moulder.
[scsmith42] 7:56 pm: My specialty is quartersawn oak, but I also have flat and
riftswn oak as well as an assortment of other species.
[scsmith42] 7:57 pm: The floor is wide open as to questions; unless anybody has
something to ask up front I can start with some "pre-submittals" that Jim, Bob
and Jeff submitted on the thread. Does anybody have anything to ask up front?
[scsmith42] 7:57 pm: Going once...
[scsmith42] 7:57 pm: Going twice...
[froglips] 7:58 pm: 25" Jointer/Planer... Dang (not a question persay)
[scsmith42] 7:58 pm: The Oliver is a beast. It'
[MarkE] 7:58 pm: SOLD
[scsmith42] 7:58 pm: It is one of my favorite tools to use because of the speed
and quality of cut.
[froglips] 7:59 pm: excellent, let me start by asking the first posted question
[froglips] 7:59 pm: (mine, coincedentally)
[froglips] 8:00 pm: Well, I have always wondered what wood you'd suggest for a
single slab workbench top.
Maybe 3" to 4" thick, 24" wide and at least 6' to 8' long.
What would be some of the issues around such a hunk of wood? I assume you would
not want one that has the pith due to twisting issues?
If one board is not possible, how about two boards?
[scsmith42] 8:00 pm: Jim, in answer to your question, I would suggest a
vertical grain (quartersawn) species.
[scsmith42] 8:01 pm: Oak would work, as would cherry, maple, or a host of other
woods. I would suggest something fairly hard.
[scsmith42] 8:01 pm: You can use one board. I actually have a workbench project
in my shop right now. It is 4' wide, 6' long, and 14" thick of riftsawn oak.
[froglips] 8:02 pm: dang, dang and dang
[scsmith42] 8:02 pm: And before someone claims that I made a typo... I didn't.
The top really is 14" thick. I made it from one of the logs that you see behind
me in my avatar.
[mquan01] 8:02 pm: how much does someting like that weigh
[scsmith42] 8:02 pm: A couple of thousand pounds.
[mquan01] 8:02 pm: why so thick?
[scsmith42] 8:03 pm: Jim, back to your question - yes you would want to avoid
the pith. A couple of vertical grain 12" wide planks would be best.
[scsmith42] 8:03 pm: mquan - because I can....
[arnie] 8:03 pm: So it is a matter of preference
[froglips] 8:05 pm: i know whats at the top of my christmas list now
[scsmith42] 8:05 pm: Yup. The most practical thickness would be around 4" or
so. Re my 14" bench, since I own a sawmill and some heavy equipment, I thought
that it would be fun to do something different. It's worth it just to see (and
hear) peoples reactions when they see it.
[scsmith42] 8:05 pm: Jim, any other questions re the workbench top? It would be
nice to do it Roubo style.
[froglips] 8:05 pm: you read my mind
[froglips] 8:06 pm: We can come back to this topic, on to Woodartz question:
[froglips] 8:06 pm: If I obtain some nicely kiln dried wood what can I do to
prevent cupping, twisting, etc. when it sits in my garage shop and adjusts to
the moisture content of its new environment?
I'm considering using oak for an outdoor bench project. Would Red or White Oak
be the best choice for this project?
How long does it take to dry a load of oak in your kiln set up? What is the
typical moisture loss from start to finish?
[scsmith42] 8:06 pm: Re the 4" workbench top, it would be best to let it air
dry for a year or two before assembly it.
[scsmith42] 8:07 pm: Moving on...
[scsmith42] 8:08 pm: The best way to store KD wood is to flat stack it. It
should not be placed directly on the concrete, as it can absorb moisture
through the slab (unless you have a great vapor barrier underneath the slab).
You may get a little movement on the top board, but otherwise the lumber should
stay flat.
[scsmith42] 8:08 pm: Re the outdoor bench project, white oak is the best
choice. Red oak is an open pored wood, and does not last well out in the
weather (unless you're in the desert). Some of Ivey's cypress would be a great
choice too, as it is a nice soft wood and does not spliter easily.
[Canuck] 8:09 pm: Then no stickers at all required for kiln dried (except at
the bottom, Scott?
[scsmith42] 8:09 pm: Wayne, that is correct.
[scsmith42] 8:10 pm: There are a few different dimensions to consider though.
First, when the wood comes out of the kiln it will have a moisture content of
less than 10%. Depending upon the environment, it may pick some back up. If you
flat stack it, the rate of gaining - or losing moisture is much slower.
[scsmith42] 8:11 pm: Now, let's say that you want your boards to acclimate to
your shop (maybe they have been stored somewhere and have gained some MC), and
that your shop is humidity controlled. In that instance, you may want to
sticker the boards so that they can lose the extra moisture.
[scsmith42] 8:12 pm: If the boards are already below 10%, then the best thing
is usually to flat stack them.
[scsmith42] 8:12 pm: Regarding time in the kiln, each species of wood has a
recommended drying rate based upon it's thickness.
[mquan01] 8:13 pm: scott, is that true for most woods?
[scsmith42] 8:13 pm: Yes.
[scsmith42] 8:13 pm: As long as they are already KD and below 10% MC.
[scsmith42] 8:14 pm: Regarding drying schedules, a species such as white oak
has a targeted daily drying rate of 2.5%.
[Jeff Mills] 8:15 pm: <--- raises hand
[froglips] 8:15 pm: nice! thats Jeff's first question!
[scsmith42] 8:15 pm: based upon a 4/4 thickness. 6/4 WO's drying rate is .6 of
the 4/4 rate, and 8/4 oak's is .4 of the 4/4 dring rate.
[Mike Davis] 8:15 pm: wait, what good is kiln drying if the wood is already 10%?
[scsmith42] 8:16 pm: Typically green oak has a moisture content of 60%, or
thereabouts. Thus, in a perfect world it would take 20 days at 2.5% per day to
reduce the moisture content from 60% to 10%. The reality is that it takes
somewhat longer.
[scsmith42] 8:16 pm: Mike and Jeff, I'll get to your questions in just a second.
[Jeff Mills] 8:17 pm: I'm good thanks
[scsmith42] 8:17 pm: The most critical portion of the kiln drying process is
the time between when the wood is green and when it drops down to 35% MC. Most
of the damage to wood can occur then.
[scsmith42] 8:18 pm: I've seen some differences in the drying rate between flat
sawn and quartersawn lumber. Typically quartersawn takes about 25% longer to
dry than the equivalent flatsawn boards.
[scsmith42] 8:19 pm: At the end of the kiln drying process, the kiln operator
will typically put the load through a "sterilizing" and "Conditioning" cycle.
[Mike Davis] 8:19 pm: could someone who was here from the start copy and paste
in an e-mail to me PLEASE?
[scsmith42] 8:19 pm: Sterilizing is done in order to kill any bugs in the wood.
Mike, this is why it is a good idea to put wood in the kiln even if it is at
10% MC.
[froglips] 8:19 pm: already on that mike
[Mike Davis] 8:20 pm: THANKS!
[scsmith42] 8:21 pm: Conditioning is done in order to equalize the MC
throughout the board. When you're drying, the outer portions of the wood dry
more quickly than the core. It is not uncommon to see a delta of 2% or more
between the core and the shell. Thus, if the core of the board is at 6%, the
shell may be at 8.5% MC. Conditioning equalizes the MC across the board.
[scsmith42] 8:22 pm: I'll pause for a second to see if anybody has a question...
[Jeff Mills] 8:22 pm: I have one
[scsmith42] 8:22 pm: Go for it!
[Ivey] 8:22 pm: I have 100
[Jeff Mills] 8:22 pm: hey Scott thanks
[scsmith42] 8:23 pm: <grin> Ivey, I've got all night!
[Jeff Mills] 8:23 pm: so for heavy oak - do you know what the MCLPD would be on
oak over 8/4 thick?
[Ivey] 8:23 pm: LOL I'll just read
[scsmith42] 8:23 pm: Jeff, it depends upon the thickness. For those wondering
what MCLPD stands for, it's "moisture content loss per day"
[Mike Davis] 8:24 pm: MOISTURE CONTENT LOSS PER DAY
[Mike Davis] 8:24 pm: beat me to it
[scsmith42] 8:24 pm: 8/4 oak is targeted at 1% if it is white oak, about 1.4%
if it is red oak.
[Jeff Mills] 8:24 pm: ok - can you point me in the right direction?
[Mike Davis] 8:25 pm: 1% per inch?
[Mike Davis] 8:25 pm: no 8/4 i see that
[scsmith42] 8:25 pm: Jeff, for a 12/4 or 16/ oak plank, I would suggest that
you air dry it in a cool location for about 1 - 2 years, and then slip it into
the kiln when it is below 25% MC.
[scsmith42] 8:26 pm: Mike, it's an exponential equation.
[Jeff Mills] 8:26 pm: a lot of folks ask for 16/ 4 thick lumber - every stick I
ever cut that thick cracked
[scsmith42] 8:26 pm: Jeff, I would also start the process in the fall, so that
the first six months of drying took place when the weather is cooler outside.
[scsmith42] 8:27 pm: The rate of drying is contingent upon the temperature, the
relative humidity, and the rate of air flow across the wood.
[Jeff Mills] 8:27 pm: yeah maybe wrap each board in burlap or something too?
[scsmith42] 8:27 pm: For a slow drying species such as oak or sycamore, if
you're going to air dry it's best to mill in the fall, so that the air drying
rate is slower for the first several months.
[Jeff Mills] 8:28 pm: good point on fall sawing - thanks
[scsmith42] 8:29 pm: All - one thing that is not widely understood about kiln
drying of hardwoods, is that you're not trying to "speed up the drying process"
during the first few weeks. If anything, on a species like oak your goal is to
slow down the drying rate so as to not cause damage (surface checks).
[scsmith42] 8:29 pm: ok. I"ll pause for a moment for some more questions.
SEE MORE IN THE NEXT POST: