Oh, the pain... Help me! I'm shrinking!

[William Lohr]

Hello all...

This is my first post, but I have been lurking and learning for some time now. My many thanks to all of you who never knew you were teaching me while you posted.

By way of introduction and background, my brother was a cabinetmaker in Morgantown, WVa and I caught the bug from him. I started making Krenov planes at a course with David Finck, and then stepped up to the Clark & Williams course at Kelly Mehlers school. But I am not a total glutton for punishment; I have a nice selection of Norm-ware as well. I have crammed my garage with toys to point of critical mass. :) Some built-ins here, some bent laminations there, a box or two as gifts, the occasional walking staff for boy scouts, and a homebuilt pine workbench ala Popular Woodworking. Two steps forward, and a few back.

So... now to the post... I had been making alot of sawdust recently working on duplicating one of the toolboxes in Jim Tolpin's book on the same topic... the one with the coopered lid and buffalo nickel pulls. So, I'd learned to use Sketchup well enough to produce drawings, which was a first. I re-sawed and edge-glued my pieces to get the walls and bottom. Used my nifty new Grizzly table saw to get uniformity of width without having to bang the heel of my hand on the fence any longer, also a first. I borrowed by brother's Leigh jig for some of the dovetails, all the while working up the skills with my handsaw. All was going along splendidly.

That was about three weeks ago. As with all things, life and work put me on hold, but glue up was to be this past weekend. I even bought two extra clamps to be sure I had enough on hand.

My pieces shrank (with the recent winter arctic snap and drop in humidity) by about 1/8" - 3/16". A little cupping too. I just didnt think the movement would be so severe. And a cry went up in Frederick, MD, heard 'round the world. :)

The best laid plans of mice and woodworkers.... live and learn.

So I am trying to re-humidify them in hopes of reclaiming the work time.

Oh, how I long for the day when the shop is heated and humidified year round. I commiserated with my pal Evan Williams the rest of the weekend. :)

Be well, all. If I am lucky and proud, I will someday post photos.

William

[Lee Schierer]

It sounds like your material wasn't fully dry to start with. Even if you "re-humidify them" they will likely shrink again in the winter months if used indoors. You best account for seasonal wood movement in your projects or more "cries heard round the world will come up from Frederick, Md." Those same pieces will likely get larger in the summer months in Maryland humidity. I would also recommend a moisture meter be added to your list of tools to get so you know where your lumber is before you cut it to size.

[Ryan Hellmer]

I feel your pain, I recently glued up some panels in bulk. The widest of them will be less than 18" with most 8-12". I glued them up in 3-4' sections to be ripped down later. Since it's been cold (mid 20's) here in KS and I don't heat my shop full-time, I figured I'd glue up in the basement. Things went great, a couple nights later, I heard a bang in the basement and went to check it out. The glue-ups had shrank enough to loosen the clamps. One of the larger pieces (about 50" wide) had shrunk more than 1/4". Anywho, it's the nature of the beast. I try to design all my projects to accomodate the shrinkage. I use virtually all air-dried lumber from our sawmill so that proves to be quite challenging sometimes. I agree that re-humidifying may be asking for trouble, maybe rip and re-joint?

Best of luck.

Ryan

[William Lohr]

It sounds like your material wasn't fully dry to start with. Even if you "re-humidify them" they will likely shrink again in the winter months if used indoors. You best account for seasonal wood movement in your projects or more "cries heard round the world will come up from Frederick, Md." Those same pieces will likely get larger in the summer months in Maryland humidity. I would also recommend a moisture meter be added to your list of tools to get so you know where your lumber is before you cut it to size.

Ya know, I went from 5/4 rough lumber to 5/8" S4S material and I believe the thinner material responded to the humidity changes much more quicker than the rough material, and surely more quickly than I anticipated. It was all equilibrated for several years and was holding nicely at 8%. This was still unfinished wood, so I'm not getting any benefit from the slowed rate of water exchange provided by finish.

I did some "cyphering" on relative humidity and wood movement. A change from 8% to 6% across 12" would be nearly what I have experienced. It could well be drier still. My Lignum meter only goes to 6%. I did however just order a wet bulb hygrometer for the shop. I'll be paying more attention going forward.

Hind sight is 20/20. I'll be lucky if I dont get to start over.

Thanks for the input. Much obliged.