Watching Wood Dry

MountainDon · November 16, 2007, 09:43:21 PM

I always knew green wood weighed a lot more than dried wood. Ask my trailer springs. :-?

I cut a round off a log the other day. This section came from a freshly cut live Ponderosa Pine. It's not an even slice. One edge it's about 9/16 inch and at the thickest point about an inch. That's a 12 inch floor tile to give a sense of scale. Hmm. The grout needs cleaning.

It weighed 2 lbs, 6.5 oz. on the 12th, the day I cut it. As of today, the 16th, it has lost a full pound of water. That's about 16 fluid ounces.

Just in case your day was going slow, or you were interested.

glenn kangiser · November 16, 2007, 09:56:27 PM

It will have to lose all of its extra water before the cells will start losing their water then the shrinking will start. I have measured around 5/8 to 7/8 inch per 12" wide board.

A log will shrink for about 2 yrs if solid - not split.

November 16, 2007, 10:31:11 PM

Don, would you consider this more or less exciting than watching paint dry :question [smiley=smiley_up.gif] [smiley=smiley_down.gif]

MountainDon · November 16, 2007, 10:39:05 PM

I'd say the wood is on a par with the paint. Although the wood would be a longer term project. A side bonus is that it is portable unlike most of my paint projects.

It took 3 days for the first cracks to appear. Many very fine cracks/checks on the sanded side whereas the rough cut side is only clearly showing one larger crack. As well it is noted that near the thinner edge there is not yet any visible cracking. The cracking is more pronounced as the disc thickness increases.

desdawg · November 16, 2007, 10:44:36 PM

I would have guessed the opposite, that the thinner part would be more susceptable to cracking.

November 16, 2007, 11:22:06 PM

Beats watching TV.

desdawg · November 17, 2007, 08:13:18 AM

Norm Abrams has nothing on us. If he ever travels out this way again we can show him a few tricks. He did a house in Tucson at one time.

PEG688 · November 17, 2007, 12:21:45 PM

Quote

#1:Norm Abrams has nothing on us.

#2: If he ever travels out this way again we can show him a few tricks.

#1: I think most folks on this forum could learn a lot from Norm.

#2: I also think Norm listens and learns from other people his show has shown that thru the years , different tools and techniques have been tried and taught.

And Mtn. D, all in all the most riveting thread on the board this week 8-)

Not that that sez much for what's been bantered / talked about :'( :'(

desdawg · November 18, 2007, 08:20:31 AM

Peg I agree. Norm is a superb craftsman. He has tools I never dreamed of at his disposal. And he has one thing that has always been in short supply for me-patience.

November 18, 2007, 08:13:19 PM

The disc seems to have settled at 1 lb. 5 oz. That's where it was Sat AM and that's where it was when we got back tonight. That's a loss of 17.5 oz of water.

Thanks Paul. 8-)

peter nap · November 18, 2007, 08:28:34 PM

I agree PEG...Especially about this thread. I've weighed gun stocks, measured them as they dry and checked the moisture content.....but Don is doing this with his usual methodical, through technique. I'm kind of interested in the checking.

Stick with it Don !

Norm is tied with my top two woodworkers. The other is Roy Underhill. I worked with him on a movie once and he is just as interesting and just as big a character in person as on his show. And yes....he cut himself

MountainDon · November 19, 2007, 07:13:12 PM

Something strange going on with my wood disc. $:-\$

The first image I posted was of the B side, with my inscribed notes.
Here is the A side, the sanded side, taken at the same time, 7:37 11/16.
The thinnest part of the disc is at about 7 o'clock. Note the series of fine cracks checking that appear in the upper part of the disc. Also the one larger crack at 9 o'clock.

Below is a shot I took today, 4:46 11/19. Note that the upper cracks have nearly all completely closed up while the crack at 9 o'clock has become much larger.

I would have never thought something like this could happen. Here is a closeup of the "healed" area.

I should own a Moisture Content meter to make the data more complete...

glenn kangiser · November 19, 2007, 07:31:11 PM

My guess would be that shrinkage, hence forces of tension are greater in the sap wood on the outside than they are in the drier wood in the heart.

This caused the smaller cracking all around until the 9 o'clock temblor let loose and relieved tensions once more. Sorry -- I got to thinking earthquakes there for a minute.. and how a quake can relieve tensions along the entire fault line.

MountainDon · November 19, 2007, 07:45:43 PM

Same thing. If you'd been an ant or something walking across the disc when it underwent the transformation you'd likely have felt something. Or lost a leg in a closing crevasse.

November 21, 2007, 07:56:49 AM

Wow, watching wood dry is a lot more exciting than watching paint dry! Paint just dries, that's it. No opening and closing crevases or anything. This is much better.

Kinda like watching an action movie.

glenn kangiser · November 21, 2007, 10:45:47 AM

Exciting

Do you have enough Smileys yet desdawg? I see you are enjoying them.

John mentioned we could do more with them so I checked it out a bit.

Sassy · November 21, 2007, 12:31:14 PM

Yes, I'm surprised that this would be such an interesting threat!

glenn kangiser · November 21, 2007, 12:34:15 PM

Quote from: Sassy on November 21, 2007, 12:31:14 PM
Yes, I'm surprised that this would be such an interesting threat!

Ah-- yes ... an interesting threat. MountainDon. He could attack us with drying wood disks. [eek]

MountainDon · November 21, 2007, 02:29:27 PM

I never mentioned before, but that is an 86 year old Ponderosa. Things grow slowly up there in the mountains. Some rings were very narrow/thin.

glenn kangiser · November 21, 2007, 03:01:45 PM

Interesting.

That is pretty old for that small.

November 21, 2007, 09:23:12 PM

Yeah Glenn, I have to play with the smilies. You can add more if you want. I see I am not alone with that.
You found a couple that suit me real well.

MountainDon · November 26, 2007, 05:29:28 PM

In the past few days the round lost another 0.60 ounce. The split increased considerably. I had it sitting under one of the hot air registers/outlets.

I guess that's about all more than likely.

glenn kangiser · November 27, 2007, 12:58:57 AM

I think you should now start taking measurements and see if it widens.

desdawg · November 27, 2007, 07:10:30 AM

I have been doing some reading about cordwood construction and there seems to be some different opinions regarding drying time for the wood to be used. And it varies by species. Softwoods (conifers) seem to be the first choice with cedar high on the preferred list. Hardwoods are more susceptable to shrinkage and swelling. So what I have been reading would indicate that hardwoods be dried for less time so there wouldn't be a lot of swelling when they get into the mortar. Rob Roy has written a few books on the topic and he has a website. See Rob Roys comments here:
http://www.greenhomebuilding.com/QandA/cordwoodQandA.htm#types
I had been assuming that my Junipers were a form of cedar. They smell like cedar when you cut into them. Come to find out that they are classed in the cypress family. Very confusing to this country boy as I had always thought of cypress as a wood that came from wet environments as in Florida swamps. I think the entire process is a work in progress and your research is probably the right thing to do. You may want to experiment with more than just the one variety of wood.

glenn kangiser · November 27, 2007, 09:38:00 AM

I have heard of hardwood getting wet and breaking walls when it swells -- probably in the Rob Roy book.