20'+ pine beams

dhp3228 · January 29, 2016, 07:36:30 PM

Started cutting some 8"x10"x 20'+ long pine beams. Could y'all advise me on how to cut these beams so that they won't bow or cup. My first one had about a 1" cup which effected my overall dimension in that end. The far end was spot on. Do y'all have any ways or methods of sucking the beam down to the bed of the mill to ensure the beams ends up being the proper dimension?

As always thanks very much and I'll be putting what y'all say to practice on Monday.

Brad_S. · January 29, 2016, 07:49:14 PM

Are you trying to make the beam in 4 cuts? That would be removing too much material at once.
If you are taking off 1inch boards already and keeping the heart centered but still getting bowing, you have little choice but to sacrifice a few boards and get to within an inch of your target size and then take thin cuts down to your target size constantly turning the log after each cut to balance the stress relief.

sawmilljoe · January 29, 2016, 07:50:26 PM

If you center the pith (heart) on both ends at the start . And saw down on all 4 sides going around the log turning after every couple cuts till you get down to your beam size with the center of the pith in the center of your beam should give you good results.

Percy · January 29, 2016, 07:54:42 PM

You can ratchet strap the cant before it is cut to size. Involves alot of stopping the cut, repositioning ratchet strapps etc. but the beam is accurate allthough curved OR without ratchet strapping, you can keep skimming the appropriate face till its cut to size. Wastefull but strait....

dhp3228 · January 29, 2016, 11:17:29 PM

I had thought of ratchet strapping it. I had heard about taking planks off the sides and rotating to relieve stress but had forgot about that tip. I am making the beam in about 4 cuts. I have been saving the outer slabs as they have to much valuable lumber still in them.

So on Monday I will try to relieve the stress in the beam and if that doesn't work I'll try to ratchet strap it.
Mthanjs and gave a good weekend.

drobertson · January 30, 2016, 07:48:29 AM

As mentioned, take off the side lumber as you go to the target dimensions. Also picking the straightest logs, ones with the heart pretty centered will help too, while sawing keep an eye on how the log reacts,(raising up somewhere) and flip and saw accordingly. For a beam that size I would say sacrificing a waste board if need be would be an acceptable loss. I've had to sneak up on dimensions before due to bowing.

ladylake · January 30, 2016, 08:03:28 AM

Also make sure you mill is set up good on those long ones. Right before you turn the log take a skim cut then turn 180 and make sure its laying on all of the bunks. If the ends are off the bunks you need to adjust your jacks or supports up on the ends, if the center is off the bunks the center jacks need to be adjusted up. Steve

customsawyer · January 30, 2016, 09:37:36 AM

Pay more attention to the pith through out the length of the log than you do to the pith on the ends. Also watch how the board or slab is moving while you are cutting it. The timber will be trying to go the opposite direction.

dean herring · February 14, 2016, 09:37:57 AM

I've got to cut 20 6x6x18' green, cut down 2 weeks. 23"on big end 16" on small end.
Should I level center of log, take some 1" or 2" cuts until I get down to a good flat surface then roll 180°,then check the flat side that is on the bed rails with a level ? If mill is set up properly shouldn't l only have to level the 1st and 3rd cuts with the toe board? Thanks.I got a lot to learn and I really don't like to waste trees. Was planning to cut them 8x8 let them air dry in the barn then cut them to size. Is this ok.