Wood acclimation in subzero temperatures


Andrew Pritchard

Recommended Posts

I'm going to start building a new workbench soon. I was going to build it out of 2" x 6" construction pine, with laminated 2" x 4" legs. The chances are the lumber has been sat out in sub zero temperatures for a while, and my shop won't be a whole lot different seeing as I only heat it when I'm working in there.

 

I only get to woodwork one day a week, so the wood will only be room temperature for one day a week anyway.

 

My question is: Do I need to let it acclimate to my workshop, seeing as any water in the wood is probably frozen in the -15C (approximate 0F) temperatures we have here in Nova Scotia at this time of year?

 

If I do, how long for?

Link to comment
Share on other sites

Acclimate your wood in the house then carry it out to the already heated shop to work. Keep the shop heated during glue up and clamping. I would let each glue up dry warm for at least 36 hours before I subjected it to freezing cold. If your wood is just construction grade you might need to store it inside for weeks or months for the moisture level to even out. Wet wood will move as it dries out. Glue will not dry properly in freezing cold. Read the glue label for minimum temperature for storage and use, then exceed that temperature. I use Titebond 2 in my shop. They say minimum 55 degrees Fahrenheit for use and drying.

Or wait until spring?

Maybe some of our folks from colder latitudes can offer a few other tricks.

  • Like 2
Link to comment
Share on other sites

My shop is in a garage that I only heat when I work. I agree with steve - you should definitely not let your glue up sit in a cold shop. I heat the shop well while I'm in there, and do my work. I glue up and then bring the whole assembly (clamps and all) into the mudroom to dry.

Obviously, finishing is out in a cold environment. Finish indoors, heat the shop and leave heated, or wait for a warmer stretch of weather. I normally spray in the front yard or garage stall, so I can't really spray in the winter. I need to brush so I can do so indoors where the temp and humidity are controlled.

Link to comment
Share on other sites

Acclimating in the house isn't really feasible as there isn't really enough space for that volume of lumber. I've had to relocate from my barn workshop into a MUCH smaller indoor room workshop.

 

I've been doing much smaller projects, but my work benches are giving me backache because they are too low. Guess I'll have to find a temporary solution to that problem until spring and do a more permanent solution then. Glue ups haven't been so much of an issue recently because they projects are small, and I can leave the shop heated for the 24 hours after I work with it costing the earth! Likewise with finish.

Link to comment
Share on other sites

I assume you mean you "can't" keep the shop heated because it'll cost too much.  True that.  But if your shop is insulated and attached to your home, and you can leave on just one small heater...enough to keep the temp up in the 40s or 50s, your lumber will begin to acclimate.  Winter is dry time in most regions...I'll admit I'm ignorant about the weather in Nova Scotia.  If it's as dry as it is around here, you can get a nice jump on acclimation.  I keep a very energy-efficient 220V heater on almost all the time in my shop during the winter because it doesn't kill us on the electric bills...but it's not powerful enough to actually "heat" the shop...I turn the big boy on when I'm actually gonna work out there, and that thing drinks some juice.

 

I'd strongly urge you to take Steve's advice, and give that construction lumber a VERY long time to sit.  That stuff can be sopping wet.  Or if you're the impatient type like me, go buck up the extra few bucks for some kiln-dried hardwood.  It really won't cost THAT much more, and it'll be a better bench for it in the end. :)

Link to comment
Share on other sites

My recommendation would be to put the project off until Spring.   With the humidity in Nova Scotia, I would expect to see a lot of movement in the wood when you fluctuate between above 0 C and the colder snaps - probably even worse than we get here in the Ottawa valley.   Less of an issue with dried hardwood, but SPF can still be quite wet and tends to be relatively 'fresh' when you buy it.  If you have a moisture meter, I would not try to work it for anything requiring precision if it is much above 10%.

  • Like 1
Link to comment
Share on other sites

I've been trying not to buy any new tools, but it's getting to the stage where a moisture meter is becoming a necessity. I'm trying to teach myself new techniques rather than buying a new tool to solve a problem.

 

But I can't really do that with a moisture meter, there just isn't a replacement (unless someone has a magic trick for deducing moisture content?).

 

For now I've brought some of my already partially milled wood down from my barn workshop and sticked/stacked it in a corner of my office. It should all be pretty dry as it's been in the barn workshop for a year.

Link to comment
Share on other sites

Actually, one way you can do it with out a moisture meter is weigh a board, and record its weight.  Do it once or twice a month, once the weight stabilizes, the moisture content has stabilized, and the wood is ready to be worked.

  • Like 2
Link to comment
Share on other sites

I would not buy a moisture meter unless you are milling your own lumber from logs, and will get more use.   Three of four seasons, there won't be that much difference, unlike our southern neighbours who maintain airconditioned microclimates for most of the year.  Once you get out of winter, the indoor/outdoor swing is nowhere near as large, so for dried wood there really won't be much of an issue.  It is just the combination of working SPF in winter indoors that presents an odd challenge.

 

That said, this was a great Christmas present.   

Link to comment
Share on other sites

this is a workbench we're talking about, build it and use it.   if you could i would build a thicker top(laminate 2x4, if all available and thru bolt)and flatten as it may change through the seasoning.    build and learn with the tools and material available to you, including what time you have, it's nice to see progress.  the environment in which you choose to work  will teach you about how to choose and use your wood for it's particular cycles,  dont ship a piece to the desert  .also probably not the last bench you will build

  • Like 1
Link to comment
Share on other sites

I'm going to be building a curio cabinet out of black walnut soon but for some reason I think I should wait till spring to start. The temps have been really cold this winter in the -40c. I use a propane construction heater that warms my shop very quickly but also at the same time produces a lot of moisture. A wood stove or electric 220v heater would be much better. Building a work bench I wouldn't think would be affected but the moisture and cause a lot of warping. I built my bench in the winter and used MDF for the top lined with hard board that can be replaced. It remains stable and flat. Not sure what type of bench you are building?

Link to comment
Share on other sites

this is a workbench we're talking about, build it and use it.   if you could i would build a thicker top(laminate 2x4, if all available and thru bolt)and flatten as it may change through the seasoning.    build and learn with the tools and material available to you, including what time you have, it's nice to see progress.  the environment in which you choose to work  will teach you about how to choose and use your wood for it's particular cycles,  dont ship a piece to the desert  .also probably not the last bench you will build

 

Actually, I was thinking of using 2x6s, these ones are only $6.20 + tax a piece. The 10' ones are perfect as my winter shop only has a 5' space to put a bench. I'll only need 8 of them to make a 24" wide split top bench. Don't want any wider than that as I want the wall space behind it to hang tools.

 

Add some 2x4s laminated together for the legs and stretchers and some 2' long 1/2" threaded rods to help hold it together and keep it flatter. Stumpy Nubs talks about his 2x6 workbench and I'll be borrowing his design. My current plan is to leave gaps in the top which then act as double mortises for the 2x4 legs. I'll do a Sketchup when I have some time to see how workable that actually is, but I'm sure it'll be fine.

 

3/4" round dog holes with cams to hold work, plus I can clamp pieces using the split. I will add a vise at a later stage, if I find I need it.

 

Might need a bigger bottle of glue - it's going to be the mother of all glue ups! Definitely going to need some more clamps too - who has enough clamps, right?

Link to comment
Share on other sites

love the idea of leaving gaps"mortices" for the leg tenons.  do the glue up in stages,  the top in two halves.  you can also do the glue up on a flat surface with weights on top and wedge and block the top together or a spanish windlass.  Look for flat grain boards so when face glue, you end up with vertical grain on the bench top surface and a much more durable surface.

Link to comment
Share on other sites

  • 1 month later...

Finally got round to doing the design for the workbench:

 

post-6539-0-31226100-1392941728_thumb.jp

 

Workbench 1.skp

 

It's not very long because it has to work with my winter workshop, and the longest wall space I have is 5ft long. As I mentioned before, I'll probably buy 10ft 2x6s to do the work top, and 2x4s to build the legs and the braces. All the mortises will be made by laminating the material, except the short braces. I'm actually going to have to cut them, probably with a router and finish up with a chisel. I'll leave the tenons slightly long and then cut the end flush. I'm planning on putting wedges into the worktop tenons and long braces, and maybe draw bore the short braces.

 

The design is missing the shelf for the bottom. At some point, I'll add a vise and some dog holes and homemade dogs.

 

The circles on the front of the table top are where I'll run some 1/2" all thread through the work top to hold it all together, and hopefully limit some of the inevitable warping.

 

I can see a large bottle of glue in my future!

Link to comment
Share on other sites

So here's a question:

 

With this style of mortise and tenon joinery, is it having a shoulder on the tenon a good idea? Is it inherently stronger/more resistant to the bench racking? This thing is going to weigh quite a lot and by it's nature be quite top heavy. Worse if I start planing it's going to have more lateral force applied to it, so I need to keep the racking to a minimum

Link to comment
Share on other sites

My opinion is that the shoulder is critical. Mine uses through tenons, drawbored and glued, then trimmed flush on top. Most of my warping is due to the slab top lying around the garage for some months before I made the base. O, I also stash my 92 lb DW 735 planer on the bottom shelf for ballast.

He who dies with the most tools ... leaves a great estate sale.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.