Questions on Leveling Pith

quadracutter222 · June 23, 2019, 02:41:23 AM

Hey y'all. Broke apart my biggest log to date today, doug fir 22" top/24" bottom 16'6" long (was a bit of a beast)

I needed two 6x10s for a honey-do project, which I did get, but was off on my pith leveling attempt. Measured from the bed up on both ends and toed up the top so both ends matched. Opened it up, rolled 180 and cut again with no toe. Now I thought I would be able to get two FOHC beams, but one ended up splitting the pith in the last 4 feet. I had it thought it out to have a 1.5"x10 board come out the middle of the two 6x10s.

Is there a step I am missing? Or is this a case of trying to make square things from nature?

WV Sawmiller · June 23, 2019, 07:54:18 AM

Did the pith grow in the center the full length of the log? Lots of time pith will grow way off center and you have to adjust the lay of the log accordingly.

moodnacreek · June 23, 2019, 10:14:09 AM

Sounds like it's time to change FOHC to FOPC !

Crossroads · June 23, 2019, 10:19:55 AM

Forgive me if I read your post wrong, but if I understand your process correctly, you took your measurements from the top of the log and made them even? In which case you would have leveled the top of the log, but not the pith. You would need to take your measurements from the pith and make both ends equal from the bed.

John Bartley · June 23, 2019, 10:31:28 AM

Quote from: Crossroads on June 23, 2019, 10:19:55 AM
Forgive me if I read your post wrong, but if I understand your process correctly, you took your measurements from the top of the log and made them even? In which case you would have leveled the top of the log, but not the pith. You would need to take your measurements from the pith and make both ends equal from the bed.

Exactly. Assuming you were only looking for those two beams out of this log, you shoulda' levelled the centre of the log, squared it to the biggest cant you could get, then took your 6"x10" off each side of centre. You only needed 17" diameter in an ideal log. At 22" you had 5" to spare.

Mike W · June 23, 2019, 10:38:06 AM

Quote from: Crossroads on June 23, 2019, 10:19:55 AM
Forgive me if I read your post wrong, but if I understand your process correctly, you took your measurements from the top of the log and made them even? In which case you would have leveled the top of the log, but not the pith. You would need to take your measurements from the pith and make both ends equal from the bed.

X3 on that one JB further explains it well..

quadracutter222 · June 23, 2019, 11:09:14 AM

sorry for the confusion, it was the pith that was leveled. Perhaps I was trying to crowd the center too much as it was 2-year-old fir and some of the sapwood was less than ideal.

Would it matter measuring off the bunk vs. the rails the mill runs on? Or am I just looking for a reference?

John Bartley · June 23, 2019, 11:18:19 AM

You are just looking for a reference. Piths are not always straight and centred, depending on where the tree grew. Always crowd to the bark if possible to get the best wood. Depending on what the beams are for, a bit of wane or pith might not be a big deal.

Don P · June 23, 2019, 01:11:31 PM

For the least slope of grain in a beam set up parallel to the bark and remove the first beam, then flip, set up parallel to the bark and repeat, leaving a tapered core piece. if it is large center the pith and saw it up, if it is small and low value continue sawing but when you cross the pith you will be at a bad slope of grain

quadracutter222 · June 24, 2019, 02:20:14 AM

Quote from: Don P on June 23, 2019, 01:11:31 PM
For the least slope of grain in a beam set up parallel to the bark and remove the first beam, then flip, set up parallel to the bark and repeat, leaving a tapered core piece. if it is large center the pith and saw it up, if it is small and low value continue sawing but when you cross the pith you will be at a bad slope of grain

So with this method Don, for 6x10, you would slab down to get the 10 inch wide, then drop 6 for the thickness, and saw this as a big flitch?

WDH · June 24, 2019, 07:51:21 AM

Remember, if the pith or juvenile core is on one side of the beam, the beam will side bend like a "C" as it dries. You have to center the pith in the beam or make sure that the beam is free of the pith and juvenile core.

Don P · June 24, 2019, 08:09:59 AM

Yes, if sawing boxed heart level the pith, if sawing FOHC saw parallel to the bark. Your experience with dougfir growth stress comes into play also. If they tend to bow as they come off the log you might be better off dropping say 7", let the stress loose then put it back on the saw and skim both faces to get it down to 6 to flatten it. That gets into slope of grain in the thickness as you do that so try to keep that kind of thing to a minimum. Some of our eastern woods peel up like a potato chip when trying to saw FOHC but I've used a number of really nice FOHC dougfir timbers over the years so I'm guessing it is less of a problem with them. I have better luck when the log is relatively huge and the timber is well away from the reaction wood in the juvenile core, your log was really not that big for this. It keeps milling interesting!

Danny and I just posted on top of one another, yup, what he said. I'm going to pull a moodnacreek :D, I like the standard terms bow and crook to avoid confusion.