Weighing down slabs

[MrWho3006]

Can someone help me out on how much weight I'm supposed to have on my stack of slabs? I found a website that had some numbers and had a pounds per square inch number but can't find it anymore. I cut pecan slabs 8' long and averaged 25" wide and 2.5" thick. I have them stacked and stickered double wide about 4' high right now.

 

[Brendon Phillips]

Wrap it in several large ratchet straps, padding it with trash wood and crank it down. Seems to work fine for me.

 

[jrhannum]

I'm a bit cheaper -- use a loop of trucker's rope and an iron bar to twist it down very tight "Spanish Windlass"-style; have a tie-back cord to retain the bar; go back and re-tighten as needed; apply at least every 24 inches along your slabs, start close to each end. My "drying rack" was once the end-column of a "gorilla rack" like you see at Home Depot --- it lays flat and is strong enuf to hold the tie-wraps. Keep it simple.

 

[MrWho3006]

Well here's what I came up with. Pallets on the bottom and pallets on the top. Filled the water totes with 75 gallons each. That's almost 1300lbs on top. I can add more water if I need to. I was just wondering how much is enough and how much is too much? This is my first time and the easiest way I could think of. I've got a bunch of these totes laying around doing nothing. Pretty easy to regulate the weight.

 

[Brendon Phillips]

That.... Might be a little overkill. But one things for damn sure, those boards aren't moving. Ever. Till the end of time.

 

[Brendon Phillips]

Just don't put so much weight on it that it's gonna dent the boards where the spacers are. I don't think it's as big of a deal as some make it out to be. Maybe a couple hundred pounds or some ropes to tie it down like jrhannum suggested. I like that method. I happen to have a ridiculous amount of 10k lb ratchet straps laying around, so that's what I use. The tank thing should work fine as long as it's evenly distributed on the lumber.

 

[Dave Boyt]

I use a similar system, but with 55 gal barrels. Pumping the water for weight is much easier than lifting weights in place... as long as my wife doesn't siphon the water out of them to irrigate the garden.

 

[MrWho3006]

Yes, it was pretty easy just to pump it in. I'm guessing I'll be able to siphon the water out once I'm done. Next time I'm going to put one solid pallet across the top and then put the totes on that. I'm thinking it will distribute the weight more evenly. There are quite a few things I'm gonna do different next time. I sure did learn a lot on my first try. Lol. It's funny how you can plan, and plan, and plan in your head and then when you actually do it, you change almost everything. There's no replacement for hands on experience.

 

[huskyhank]

Or leave it alone.
I don't get much movement without any weights or binders at all.

 

[Dave Boyt]

Good point, huskyhank. Depends some on the species, but with 25" wide boards, I'd sure weight or strap them down to cut down on cupping. May wind up straight line ripping, planing, and gluing them back together, but this way, they stay together. MrWho, are you doing anything about air circulation? Maybe at least open up the barn doors on sunny days.

 

[Brendon Phillips]

Or leave it alone.
I don't get much movement without any weights or binders at all.

Yeah, I have some black walnut that only has about 100 lbs on it. And two boards that are just laying there all alone. Does fine. But if can't say that for every species and every cut. The weight def doesn't hurt though.

 

[MrWho3006]

Good point, huskyhank. Depends some on the species, but with 25" wide boards, I'd sure weight or strap them down to cut down on cupping. May wind up straight line ripping, planing, and gluing them back together, but this way, they stay together. MrWho, are you doing anything about air circulation? Maybe at least open up the barn doors on sunny days.

Yes, there's two windows that stay open and an 8' wide entry that stays open. The hay will be gone soon also. The plan is to let them air dry for 2-3 months then send them to a kiln I found east of San Antonio called Swift River Pecan. Pecan is what he deals with most of the time. He is the one that suggested to let it air dry before sticking it in the kiln. I just guessed on how much weight to put on top. I figured it would be easier to plane out sticker indentions than to plane out cupped boards. But idk, this is my first time.

 

[MrWho3006]

Or leave it alone.
I don't get much movement without any weights or binders at all.

Well I have some short pieces that that were cut about 2 weeks before the rest and just laying on cement under a covered patio and they already started cupping. That really made me nervous that those pieces already started cupping after two weeks! I hope the weight will flatten them back out. We will see I guess.

 

[huskyhank]

Laying on a cement slab will do that. The boards will dry lots faster on the upside exposed to air than on the side on the cement -- and then warp.
I've even stood slabs up on end leaned against a building and gotten good results. But my good results are not commercial expectations. There is gonna be a lot of degrade to this game, and I don't find it particularly beneficial to try to make it too much otherwise. Anchorseal coated ends, good stacking, with good stickers and careful control of airflow to the stack and complete cover from rain and sun is my limit.

 

[Grey]

You are on the right track. For weight I just us row of cinder blocks over each column of stickers. It has worked fine for me. Do make sure you get some air movement.