iDRY Vacuum Kilns

Sponsors:

timber layout in log

Started by ben bb, August 21, 2020, 11:44:49 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

ben bb

Hi All.  I'm trying to figure out how to best to plan cuts in some logs.  I have red oak (I believe blackjack oak) logs around 24"-26" diameter.  As I understand it, I should either center the pith or not include in timbers.  Is that accurate?  If so, how far away from the pith should I stay?  For example, could I cut two 6x8 beams out of the center by cutting right through the pith on the 8 inch side, or should I take a 1x8 or 2x8 with the pith out from between the beams?
Thanks,
Ben B
Memphis, TN

Don P

The risk of bowing in hardwood is pretty high, so if you decide to try free of heart timbers be ready to turn the timbers into boards as you saw. I would center the heart in one 2x and make that my first cut. The 2 pieces will bow apart while sawing, you'll need to make a judgment call then as you see how much. If it requires too much to flatten the bowed faces the slope of grain will be too great and the only use will be lower grade sheathing. Flatten and take the 2x. Flip and take boards till you get to an acceptable face from the bark side. You may need to keep rolling 180. Finish down to thickness by removing from the heart face, that will put the clearest wood furthest from heart into the timber. Stand up, center the cant and work those faces, again you may need to flip 180 several times as you release the growth stress. Loss is probably going to be high but if it works it will be higher grade with less checking.

There is a good paper online from a green oak timberframe company in the UK that describes and shows historic examples of different sawing patterns and results from there. I posted a link here at some point in the last few years.

ben bb

Thanks for sharing this Don.  Very helpful as always.  That makes sense, although a little disheartening since I just use a chainsaw mill.  I'm thinking a better plan would just be to cut the outer part of logs for sheathing and plan on just being able to use the middle for timbers.  I'll just have to take a few more trees that are smaller to get all the timbers I need.  I need sheathing anyway, so it sounds like this approach will likely have better results.  Is 4/4 standard for sheathing?

Don P

I know a lot of guys don't, but I dry and plane just about everything so it will lay as flat as possible, hardwoods especially like to cup as they dry. I usually saw 1-1/8" thick and plane to 7/8 or 3/4.

Brad_bb

If the log is fairly symmetric, level the pith and take one boxer heart timber out of the center.  Take 4x8 or 6x6 brace stock from outside the center timber.
Anything someone can design, I can sure figure out how to fix!
If I say it\\\\\\\'s going to take so long, multiply that by at least 3!

Dave Shepard

Oak is going to move a lot if you split the pith. I would saw over size, then trim to final dimension. Pine is more forgiving. I've split a 15"x15"x47' cant into two 7.5"x15"x47' timbers with no noticeable movement. 
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

Thank You Sponsors!