Hey All, Something I've been curious about regarding the control of movement of lumber as it dries.
Will the use of say ¾" poly banding on a stickered stack help control the warp and twist of lumber? It can be tightened as needed, plus won't rust against the boards.
To me it makes sense, but wood is also a powerful substance. Maybe someone has gone this route and give some feedback....Thanks
Good Morning Richard, I use poly banding not sure if it helps with twisting but I know it does loosen up. I use the buckles so I do tighten it as it dries. I fine the main benefit is keeping the stacks together as they are moved.
www.forestryforum.com/board/index.php/topic,48895.msg706076.html#msg706076
This system that Jim developed and banding has changed my way of storing and handling lumber for the good
Proper stick placement ,stack setup and weight helps with most timbers but some stuff you just cant stop from wanting to move Mate :) :) ;)
Thanks for the link Bill! Darn good idea, especially for using up scrap lumber. Now if I had a forklift to handle that kinda weight! Hmmmmm
I figuered on placing the strapping at every other sticker and binding down tight. And with the buckles, if needed through periodic checks the strapping could be bound down tight again. I thought this may allow the elimination of using weight on the top of the stack. Or at least help keeping things from moving.
Appreiciate the input fellas!!
Hi,
i have done some research over the last couple years in the field regarding the use of polyester strapping (not polypropylene). We have very good sucess improve the wood grade during the drying process. (this greatly contribute to reduce twist bow and arc with the SPF (softwood) from green to a 15-19 m.c. for hardwood at 7% the srhinkage is just too much for the strap to keep any residual tension. We have improve the grade in industrial application from .5% to 4%. this also help with handling of the pile in rough yard... You have to apply enough residual tension on the strap to bring in into it's working range so it will tend to follow the perimeter reduction and keep some tension. Normally we are using 5/8'' X.040 strapping break strenght of 1600 applied at 400lbs-450lbs of initial retained tension. These study have been done into industrial mill with annual production from 50millionbft to 400million bft at temp ranging from 160 to 240. I have test it on air drying lumber with my own lumber coming from my woodlot saw with a portable sawmill with great result. Since you are applying the strap at high tension it is important to apply it close to the sticker otherwise you will create a permanent deformation.... hope this helps....
Black spruce, for your first post that was superb! Welcome to the fold.
I use the 5/8 Poly strapping and am happy with it. I do not count on it to hold drying lumber straight. I used the buckles. Now I just clamp the strapping.
kderby
I used old garage door springs ( the heavy ones) cut into 10 inch pieces with the ends bent up. incorporate them into your straps. I use the cheaper ratchet straps and strech the springs out about 3 or 4 inches. when the lumber shrinks the springs take up the slack so you don't have to retighten them. I put 1 spring on each side with 2 straps. 6 straps and 6 springs per stack.
Think Ill just throw this out there what about 5500lbs ratchet straps say every 4' could work I reckon ;):)
Might work until the lumber stack shrinks from drying.
i use to rachet strap my kiln loads 4 straps per 8 ft bundle after doing this for acouple yrs. i stopped. it really didnt seem to help enough to make the extra labor worth it. wood will warp or cup or twist if it wants to you arent really going to stop it . imho
another twist to it, when working with the strapping to help improve the grade we have found that since we are strapping a rectangular load and not a round load everytimes we go around a 90 corner we loose tension due to friction and since our goal is to create a downward force to on the top row so that the strap will act like weight. Or you will remark that when using only strapping you will have the piece in the middle of the 2-3 first will bend and the package will have a bit of a football effect to the point that you could pull out the board in the middle of of the row. So We are using 3x3 batten on the top theses are stronger (no bowing effect ) The batten has to be minimum 3 x3 so it is mecanically stronger than the force of the strap so it absorb the energy and transfer it down to the stack the result are impressive. if you put your batten close to the sticker you are spreading the downward force toward the sticker and contribute to really put a force where it count. in industrial world we are using automatic strapping machine with compression this take al the void out the load. In smaller scale we are using anything like battery powered tool or aeven a manual tool that will provide great tension.