# A strange wood drying question.



## Da Aardvark (Oct 11, 2012)

I'm drying a pyramid shaped triangle that Tennessee Tim had cut for me a few weeks back.
Here's the scoop.
I'm speed drying it. It is a 3 sided pyramid, with 18" sides at the base and it sits 16" tall. It is Chinquapin Oak. Now what I'm doing is running a space heater and blowing dry air over it. I've drilled a dozen holes on the underside, 3/4" x 8", to relieve tensions and also let the piece vent out moisture faster.
There is no way to accurately check the moisture content since the center is approximately 12" in to the center. 
So I'm weighing the piece to tell me how much water weight is coming out of it. So far, the piece has went from 81 lbs to 64 lbs in 3 weeks. I'm using the weight as a guide. I'm going to use 50 lbs as my target weight.
The piece is cracking/checking/splitting as expected and is part of the overall design. I'm assuming the cracking/checking/splitting is aiding in the drying process, by acting as vent holes.

The ?????
Is there a means by judging by the weight, to assume the piece is dried sufficiently to where I can work with the piece. It's going to be a base for a coffee table.


----------



## cabinetman (Jul 5, 2007)

If you have an accurate scale, and are checking it regularly and it's losing weight, once it stops getting lighter it's as dry as it will get for the ambient conditions. This won't give you a moisture content in percentage.








 







.


----------



## woodnthings (Jan 24, 2009)

*some questions*

Why not get a moisture meter since you work with the slabs frequently? I got mine from: Sonin 50215 4-in-1 Stud, Moisture, Metal and Voltage Detector - Amazon.com

probably a better one:




\


Why the target weight of 50lbs...based on what?

The last drop in moisture content is the hardest to get and takes the most time by air drying. 

What about case hardening from drying too fast? This may be helpful:
http://en.wikipedia.org/wiki/Case_hardening_(woodworking)

If the splits and check are part of the design, what's the reason for a specific moisture content or weight? Does it matter as far as a finish coating?

Just curious and maybe I'll learn something .... :blink:


----------



## Da Aardvark (Oct 11, 2012)

Ya know Cab't?
Your answer is so obvious I'm surprised I didn't think of it. Thanks.

wood.
I have a meter but the pins only go in so far. Right now, the outer surface is bone dry.
The target weight I guess is irrelevant after Cab't's answer. The finish coatings I use are generally epoxy, and the wood needs stabilized to the point that it won't shatter the epoxy from shrinkage and a crack opening up further.
After a few months of drying with hot air blowing around it, it's going into a kiln. Then I'll cook her hard.


----------



## Tennessee Tim (Dec 15, 2010)

You know there's NO strange questions here ESPECIALLY about a strange cut!!! We're all here to learn AND we all have differ theories on what's "proper". Heavy thick chunks/blanks carry extra drying problems and speed is against all of them...as you know I'm into slow drying but on a large chunk like this shape/size very few come out without checks and since that is part of the design it'll all be great and won't be disappointing. Drying as cab'man said is the way I'd judge it in this circumstance. Have you dried using some sort of dehumidifier???

I can't wait to see the progress, IMO take a deep breathe and slow down the heat to a slow/low setting and be patient....there's lot's of water that has to work it's way out.

There is a process being tried now that uses the high heat first and then remove the moisture??? I've only read a part of the article/post I'd seen and haven't deeply investigated. It's basic theory was the immediate high heat locked the cells open and they could relieve the moisture quickly instead of being locked in. This contridicts that speed drying causes case hardening???? research and form your own opinion, this theory has pros and cons IMO.


----------



## Da Aardvark (Oct 11, 2012)

Well Tim, you know...It's a strange piece...you cut it! Strange piece, strange question.
My brother in law came over yesterday and just drooled over this triangle. He couldn't stop talking about it...


No Tim, I haven't used a dehumidifier.
In all my drying in the past, the fan on a small space heater does enough to drive out the moist air through a vent hole in a tarp. Got pieces down to below what the meter would detect (6%). I'm not to that stage of drying yet. The space heater is on the lowest setting and will run warm air around the piece for likely a few weeks more.

The cracks and splits are what I'm looking for and are fine. The checking was expected but not what I want to see. In the past I've used sawdust from 600 grit and white glue, and rubbed it into the checking. Then I start sanding. It doesn't remove all of the checking but it does quite a bit, and makes it slightly less noticeable. Seems oak has a tendency to check more than other woods I've worked with.


----------



## Brian T. (Dec 19, 2012)

Record the weights to try to dry down to a constant weight (whatever that is) = you're done.
On graph paper, I'd imagine the line will eventually slope downhill very gently = you will never see a true constant weight. When the piece isn't losing more than a few ounces per day, I'd consider it done.
The array of vent holes in the underside was a very good thing to do and for the reasons that you give.

Given the thickness of the block, the drying is bound to be uneven with the surface very dry and the inside not so much. Remember, all those little water molecules have to find their own way out of a very thick block!


----------



## Da Aardvark (Oct 11, 2012)

Thanks.
Yeah, the piece is trying to slightly distort in shape. It's only a chainsawed piece at this point so I'll be able to grind it back into shape.
Lotta stresses on it.
And yeah, you can run your finger into the drilled holes and feel slight moisture. Surface is bone dry.


----------



## Allen Tomaszek (Dec 11, 2010)

Why not cut the top 4" of the top of the pyramid, set it aside. Then drill or turn a large hole through the bottom section of the pyramid that goes all the way through to the top. That will allow the pyramid to dry faster (much like a turned vessel) and when dry enough glue/join the top back on?


----------



## Brian T. (Dec 19, 2012)

Allen, I wondered about that, too.

Is there a reason why you can't chisel out all the web wood among the underside holes?
Just leave a cavity?
Upside down version of how I hog the void wood out of a carved wooden dish.


----------



## Tennessee Tim (Dec 15, 2010)

Sounds like Allen has seen your plans!!???!!! LOL 

The hogging out the interior sounds like an awful good plan.....it'll reduce the wieght, speed up the drying and make things dry less stressed!!! a 3 in one punch. hollow the walls down to 3" and you'd be WAY ahead!!!

For the ones whom didn't see the other thread on the pyramid...link here... http://www.woodworkingtalk.com/f26/would-csm-milling-58231/


----------



## Da Aardvark (Oct 11, 2012)

Yeah, it does sound like Allen has seen the plans.
Hi allen. Check your e'mail. Plan is included. I need the flat top area for future top attachment, but the idea is sound.

Robson, I'm not set up tool wise, to do that at this time. I have most of my tools packed for upcoming move.


----------



## cabinetman (Jul 5, 2007)

Allen Tomaszek said:


> Why not cut the top 4" of the top of the pyramid, set it aside.


That seems easier said than done. How did you plan on doing that and getting a clean cut across the three sided structure? 








 





 
.


----------



## Tennessee Tim (Dec 15, 2010)

Bandsaws do miracles!!! ....IF set up right!!! Actually we discussed sawing it that way.....VERY tricky!!!


----------



## Allen Tomaszek (Dec 11, 2010)

cabinetman said:


> That seems easier said than done. How did you plan on doing that and getting a clean cut across the three sided structure?
> 
> 
> 
> ...


I would use a bandsaw somewhat like making a bandsaw box. It would be easier with a horizontal bandsaw like a small sawmill.That way the base is sitting on the bed and you're just sawing off the top.
I see your point about getting a clean cut because no matter what the kerf the edges of the two triangle pieces will no longer line up evenly. If you have to clean up the cut much then the difference only increases. It would most likely need a spacer or bezel between the top piece and the base if you did it this way.


----------



## Tennessee Tim (Dec 15, 2010)

Tennessee Tim said:


> Bandsaws do miracles!!! ....IF set up right!!! Actually we discussed sawing it that way.....VERY tricky!!!


As a whole....NO chainsaw!!


----------



## Da Aardvark (Oct 11, 2012)

I'm just going to start sanding and grinding the 3 sides flat.
I'll get there. Done worse in the past.


----------



## cabinetman (Jul 5, 2007)

Allen Tomaszek said:


> I would use a bandsaw somewhat like making a bandsaw box. It would be easier with a horizontal bandsaw like a small sawmill.That way the base is sitting on the bed and you're just sawing off the top.
> I see your point about getting a clean cut because no matter what the kerf the edges of the two triangle pieces will no longer line up evenly. If you have to clean up the cut much then the difference only increases. It would most likely need a spacer or bezel between the top piece and the base if you did it this way.


Just for a point of discussion, it's not just the differential due to the kerf. Lets back up a bit in setting up the pyramid to be cut. Either on the BS or TS, it would have to be sitting horizontally, with the base on the table, and the point positioned and held at a centerline to the center of the base (which would be vertical).

You would need a jig of sorts to have the pyramid held at the right position, and a way of moving it through a cut.



















.


----------



## Tennessee Tim (Dec 15, 2010)

cabinetman said:


> Just for a point of discussion,.... .... Either on the BS or TS, it would have to be sitting horizontally, with the base on the table, and the point positioned and held at a centerline to the center of the base (which would be vertical)....."
> 
> MMMmmm, Technically not....and actually on table saw or vert bandsaw the base can't sit on table horizontally and make the cut....impossible due to blade to table position....
> 
> ...


----------



## cabinetman (Jul 5, 2007)

cabinetman said:


> Just for a point of discussion,.... .... Either on the BS or TS, it would have to be sitting horizontally, with the base on the table, and the point positioned and held at a centerline to the center of the base (which would be vertical)....."





> =Tennessee Tim;561198]
> MMMmmm, Technically not....and actually on table saw or vert bandsaw the base can't sit on table horizontally and make the cut....impossible due to blade to table position....


What I was referring to was cutting the pyramid with machines like a table saw, or a band saw. Tools that a hobbyist may have, not a horizontal mill.

The statement about the base on the table, I meant the edge of the base as indicated in the drawing below, orienting the pyramid horizontal (on its side), not vertical. To get the absolute dead center line of the base and tip of the pyramid to be absolutely parallel to the table (saw), would be necessary. And as you pointed out..._"the centerline will automatically be correct IF all sides are correct/exact length...."_ A shop made pyramid fitting the parameters is a chore.

Figuring out projects like this reminds me of the times I had to split bowling pins and baseball bats.
.


----------



## Tennessee Tim (Dec 15, 2010)

OK, I see now what you meant....for unsemetrical pyramid your diagram would be the easiest... but with his being the same lengths in height just lay the pyramid on down to the face, find the angle the base is tilted at and set the blade to that angle. now your blade plane is horizontal to the base plane. (actually after re-thinking, a unsemetrical can be cut this way...your already running parallel plane between the blade and base)

Now to splitting pins and bats...YOU weren't loading them were you!! LOL, I'm just kidding!!! I've split columns and balusters....what projects were you building with them???? sounds ineresting.

..Mentioning columns and this project, I recall now in the old days they would actually bore the center out of a log to prevent column splits...now they build in multi glued up pieces. I've only seen a very few of these as most were 10" and less and very old process then.


----------



## cabinetman (Jul 5, 2007)

Tennessee Tim said:


> Now to splitting pins and bats...YOU weren't loading them were you!! LOL, I'm just kidding!!! I've split columns and balusters....what projects were you building with them???? sounds ineresting.


I made advertising displays that first went to bowling alleys, that had the pins as decorations. They were free standing displays, about 2' square, about 6' tall, with interior lighting, and color transparencies (actually were prints) that got backlighted. Business would pay for their "spot". It got very popular and soon also went to malls, where some sports businesses wanted baseball bats. The pins and bats had to be halved to mount close to the display.


















.


----------



## Tennessee Tim (Dec 15, 2010)

Tha sounds cool !!

Hey Cab, until now I hadn't looked closely at your atvatar?? I suppose it's a military patch??? what branch and war?? my father-n-law was veitnam and I think called black lions?? associated alot with the "tunnel ratting". 

THANKS for your service!!!! We as free Americans have NO IDEA what some have gone through AND sacrificed for our safety and freedoms!!! It's sad to see the hurt in a soilder's eyes that had to fight a war that they weren't allowed to win, do things that was unreal and then get spit on when they got home. MY PRAYERS go out to them. It took him 30 yrs to talk only some about it.


----------



## Brian T. (Dec 19, 2012)

When I take the basic guts out of a dish, I drill a crude pattern of 3/4" or 1" Forstner bit holes, down maybe 3/4". With a mallet & bench chisel, whack out the wood web among the holes. Following the existing pattern, I go down another 3/4" and repeat until I have 1/2" to 3/8" excess wood to eliminate the bit marks in the bottom. Usually, hook knives work that wood better than spoon-bent gouges. That gets me to the floor thickness that I have planned. Usually 3/8".


----------



## cabinetman (Jul 5, 2007)

Tennessee Tim said:


> Tha sounds cool !!
> 
> Hey Cab, until now I hadn't looked closely at your atvatar?? I suppose it's a military patch??? what branch and war?? my father-n-law was veitnam and I think called black lions?? associated alot with the "tunnel ratting".


I think we have hijacked this thread enough, so I'll PM you.:yes:


















.


----------



## Da Aardvark (Oct 11, 2012)

Nah. 
No hijack.
Good info.


----------



## Da Aardvark (Oct 11, 2012)

I thought I would update this thread.
The pyramid must be near dry. I've been weighing the piece as it dries. What has surprised me the most is how much water by weight and volume, is coming out of this piece.

When I bought it from Tenn Tim the piece was part of a log that had been sitting in the dirt for awhile, Who knows what the original m.c. was. After Tim cut it for me, it was soaking wet. 
Soooo....I got it home and didn't do anything to it for a few days. The surface was already slightly drying. 
I weighed it and the weight was 82 lbs. before I did anything to it.
Next I put a space heater near it on low, and let warm 70degree air blow around the piece for about 2 weeks.
I weighed it again, and it was 69 lbs..
Finally I put it in my makeshift kiln for 1 1/2 weeks on low heat (75-100 deg), and rotated it so no one spot would be more dry than the next.
I weighed it this morning and it's at 64 lbs..

So heres the math behind this. 
One gallon of water weighs 8.34 lbs. The piece as of today is down 18 lbs from the start.
18lbs / 8.34lbs = 2.156 gallons of water.

In a few days I'll do a 130-140 degree bug kill for about 2 days, and back to normal kiln temps.

As suggested I won't stop drying the piece until the weight no longer drops off. 
Currently I can still smell the scent of oak and feel some slight moisture coming out in the kiln. I'm suspecting the weight will drop further, but it is slowing down a lot.

This has amazed me at how much moisture is bleeding out of this thing. It's like 2 ea., 1 gallon milk jugs of water....I'm shocked at this. I would have never thought wood would hold that much water.

Some checking has happened as expected, and some cracking. One crack is severe, but where it is located, it won't effect the looks of the project, since most of it will be cut off when done.

In the end, when the weight stops dropping off, I'll be cutting off the top of the triangle. That then gicves me a chance to check the internal m.c. and make sure it's around 10% or less (my target moisture for live edge furniture)

Thanks for the info.


----------

