[Chris Curl]

In another thread, the idea of ripping 2x material came up, and there was a general consensus that, even though the KD lumber has been kiln dried, it is still pretty wet, making it unsuitable for ripping.

This is a follow up to that topic ... suppose I wanted to "finish" the drying of that 2x material, so that it would be acceptable stock for ripping.

So ... how would I go about such a task? Is it just a matter of separating them 1/4" or so (I have paint stirrers I can use for that!) and letting them sit for some amount of time? If so, how long would that be, if the location was an unheated (but attached to the house) garage?

 

[amckenzie4]

I've let either 2x4 or 2x8 dry stacked on a bench in an unheated garage for a couple of months, and found them completely dry (and remarkably warped) when I came back. I should mention, though, that "completely dry" is subjective, since I don't have a moisture meter. Certainly dry enough to rip easily with hand or power tools. Douglas fir seems to come from the box store wetter than SPF, for some reason. I don't recall ever seeing significant cracking or checking on 2x4, but I've seen 4x4 and 2x10 crack as they dry.

 

[mdntrdr]

It will only get as dry as the environment it is stickered and stacked in. You will probably need to buckle it down also.

Stickers are normally 1".

Where and what conditions will you be attempting this in? :smile:

EDIT...

I see now you said unheated garage. It wont do any good until summer conditions arrive. :no:

 

[rrich]

When I need dry (KD) 2x4 material, I go to Lowe's. They sell some rather good KD material. IIRC when I measured it the MC was 8%.

The price is pennies more than the truly KD/Green stuff.

I believe that the green stuff is preferred in construction because the moisture reacts with the nails and makes the nails hold better. DUNNO.

 

[Chris Curl]

so sticker it with 1" spacers and let it sit? how long?

what does "buckle it down" mean ... put a strap or around it to help keep it from warping as it dries?

 

[Chris Curl]

When I need dry (KD) 2x4 material, I go to Lowe's. They sell some rather good KD material. IIRC when I measured it the MC was 8%.

The price is pennies more than the truly KD/Green stuff.

I believe that the green stuff is preferred in construction because the moisture reacts with the nails and makes the nails hold better. DUNNO.

Good info, thanks. Is 8% considered thoroughly dry? I assume that it never gets to the point where it has 0% moisture content. Do they sell moisture content meters at the big box stores?

 

[ryan50hrl]

They used to carry a moisture meter at Home Depot....not sure if they still do. Construction lumber can get good and dry, it won't dry much in cold weather, but in warm weather it will in the garage. Keep in mind it's not unusual to find sap pockets in construction lumber that will make your blades good and sticky.

General rule of thumb is an inch a year, although you've got a head start if it's already KD lumber.

 

[tc65]

Lowes carries a General Tools moisture meter for about $25. Menards has cheap looking Tool Shop meter for $15. Don't have either, so can't comment on quality, but the one at Lowes is rated high by users.

 

[mdntrdr]

what does "buckle it down" mean ... put a strap or around it to help keep it from warping as it dries?

Yes, either strap it, or add weight to the top of the stack. :smile:

 

[Chris Curl]

Cool beans. At what moisture content would construction lumber be considered dry enough for ripping?

 

[mdntrdr]

Cool beans. At what moisture content would construction lumber be considered dry enough for ripping?

You can rip it any time you like. It wont be stable until it reaches 7-10%. :smile:

 

[Brian T.]

KD construction SPF is 24%MC when it comes out of the kiln. In any case, air-dried, outdoors under cover, the equilibrium MC will be 12-14%. KD hardwoods get the bejeezlies baked out of them to 8-10%MC.

The guys in the Diamond Willow shop will buy 50 2x10 for bed/mattress frames, stack and sticker the stuff for a year.

Queen-size, the beds go for $2 kilobucks each with the fancy DW head & foot frames. I suspect that they have a very good idea of what works and what doesn't.

 

[Chris Curl]

the only question left is how long to stack and sticker 2x4s and keep them in the garage before they have stabilized? or is it one of those things that you just have to hit is with the moisture meter every so often to see where it is?

 

[mdntrdr]

Nothing will dry in an unheated garage this time of year. If your in a hurry, bring them in the house.

Otherwise it will be summertime before they dry, and spring may add even more moisture to them.

You could use a makeshift kiln in your garage. :smile:

 

[frankp]

Chris, the simplest thing to do would be to build a small kiln, if you want some consistency. A few 100 w light bulbs in an insulated box will do wonders. If you include a fan to move the air, even better. It won't take much but it will still be somewhat slow. We had/have a member, Daren, who sells plans for a kiln that works really well, as I understand it. You can build it for less than $100 if I remember correctly. I've considered building one out of some light bulbs and a few computer fans I get free from work but I haven't done it yet.

 

[Hammer1]

It doesn't matter if the wood is green, wet or dry, for ripping. Most any lumber will react and warp when ripped down the center it has nothing to do with moisture content. If you want 2x2 pieces, buy them in that size or in 2x3 where you won't be removing so much material.

 

[frankp]

Hammer, you're making a lot of bold statements today that are completely contradictory to my experiences... I definitely see a huge difference ripping lumber that is wet versus dry as far as warping before/after.

 

[Brian T.]

As the free water evaporates from the wood, there will be some drying stress set up.
Stacked and stickered is sort of a false "in service" condition = they can dry as they are set.
In no way does this prevent some drying stress from developing. Maybe less is all I can say.

In the diamond willow shop, they considered using moisture meters. If they have any, I've never seen them. Instead, they set up the big drum sander and do a little "test sanding". Based on the dust and the appearance and texture of the wood, they know what's ready to work and what isn't.

They have used this same method for 5/4 and 6/4 birch planks. I wanted to buy some for wood carving and they refused, until they believed that the Equilibrium Moisture % level had been reached.

All that was stacked and stickered under some long work benches in a cool part of the shop. Probably 6 months in there after years in location #1.

Every shop condition is different. If you brought the wood into a warm and dry winter house, you could lose some of the bound water and it would appear to be 4-6%MC on the surface and sopping wet in the core. It just seems to take time.

 

[TomC]

Not sure what you are trying to make. I just ripped several 2"X6" SPF to make 4 folding stick chairs. I only had one problem ripping and when I felt it binding I stopped the cut and reversed the board and finished the cut. All other rips were fine. I did joint one edge of the boards prior to ripping to ensure a good registry to the fence.
Just as a note I believe construction grade lumber come out of the kiln at 15 per cent moisture.
Tom

 

[HowardAcheson]

If straightness is critical when using construction lumber I always stack and sticker the boards inside until they are at something less than 10-12% EMC. That's the only way I have found that makes the boards behave.