warped wood

[Doug]

I've spent about 5 hours milling up the piece of black walnut from rough cut to final dimension for a project, a hope chest. The milling came out pretty darn good, with the main panels (14" by 45" by 1') turning out nice and flat, at least initially. After about 48 hours, two of the four boards (by the way, they're all 2 piece glue ups) have bowed, not horribly, but certainly enough to frustrate me as I was planning to try hand cut dovetails along the 14" corner joints. How might I have prevented this? (the boards were well aclimated to the working environment, and, to the best on my knowledge, well dried

- though I don't have a moisture meter.) I'm wondering if I should continue to even try to use the dovetail plan: I'd be trying to joint two boards along a 14" joint where at least one board is bowed out about 1/16th or perhaps slightly less, in the middle.

Any thoughts or suggestions appreciated.

[Leon]

As you produce a new exposed surface the board begins to shrink or swell as the atmosphere dictates. Better to mill to the approximate thickness and then let the board acclimate again. Then finish milling to the final thickness. Also it is best to mill equally from both sides to help even out any uneven moisture content on the sides of the board.

With only 1/16 bow you should be able to machine DT the panels as long as you clamp the panel flat in the jig. Assembly will require a light preparation.

[Swingman]

Hurry up and glue up! ... the longer your wait, the worse it may get.

1/16" over 14" is no big deal and can usually be "clamped out" in the glue up of the dovetail joint. Using clamping cauls that fit over the pins or tails is one way to insure this works.

If one side is not going to be seen you can always use a couple of well jointed "battens", screwed down tightly on one side, to flatten the offending board for the glue-up, then remove them later and fill the screw holes.

But you really do need to waste no further time and "git r done".

[John Grossbohlin]

This isn't a problem for handcut dovetails... I've done them with boards cupped worse than that and they straighten out well when you glue it up. One way to deal with this is to clamp cawls to the boards to straighten them out during layout--generally no need while cutting and chopping. Alternatively, if you're careful about it you can do the layout as is and, assuming pins first, slightly reposition the pin board as you lay out the tails.

John

[John Grossbohlin]

Doug,

Just noticed your ISP... come up to Saratoga Springs to the Northeastern Woodworker's Associations annual Woodworker's Showcase the 24-25th of March. I'll be there in the hand tool demo area by Toy Factory. It's planned that I'll also be doing presentations on hand cut dovetails with Joe Kennedy. I'd be happy to show you what I tried to describe.

[Jeff]

Occasionally I see the phrase "git r done" spelled exactly like this. What is that from?

[Peter Huebner]

Heh, I had something like this happen a few weeks back, only pretty badly: ended up with some propeller blades, after dressing some boards for a bedside table top and then leaving them on a varnished assembly table overnight.

I wet down the boards, put gauged stickers between them and clamped the mess together - then I put them back on the workbench, but on edge, and with some stickers underneath so the air could circulate freely. After 36 hours they were straight enough for a fairly easy glue-up with only one or two exceptions that just had ornery grain anyhow. Fortunately I had allowed quite a bit extra since I resawed and then dressed them from some 6x1 r/s.

-P.

[Swingman]

Definitive proof that you're NOT a redneck, and also without a cable hookup!

DAGS

[Frank Boettcher]

Not unusual for that width.

However, as one who has fought the wisdom of those who have gone before me many times, I've finally given up. I don't glue up panels with boards wider than four inches. I do reverse the end grain direction in alternating boards, despite the fact that the board may be a little better looking on the other side. I've given up fighting the cross grain gluing gods, seems they win every time (I've a couple of beautiful pieces of bedroom furniture that open a very nice crack every winter).

That said, you should be able to easily fit, clamp and glue a 1/16" bow with dovetails. Might have to put a shim or strongback at the clamp point to pull in the middle.

As Swingman said, go for it now, it ain't going to get any better in the Spring.

Frank

[bremen68]

The phrase "git r done" is from the comedian Larry the Cable guy. It's his catch phrase.

Do a google search on Larry the Cable guy and you'll get a feel for him. Big fella in a plaid flannel shirt with the sleaves cut off and a cammie baseball cap. Hilarious. :-)

[Swingman]

I'm with you. For tops and lids I still try and get away with it on occasion for my own personal pieces if the wood is just too pretty and figured to chop up, and if I can batten one side when necessary. I figure as long as I'm around and eating my own dog food, a lid or top can be re-done.

But, for those pieces destined for others, the prudent thing is veneering for matched, "figured" grain on panels ... although I was slow coming to that conclusion because there is something about a veneered piece that is just too perfect and unreal for my taste.

[BobS]

Doug,

Other responses provided some good advice. I'll try to answer how you can prevent it in the future and maybe straighten what you have.

First, you may have released stresses in the wood that caused the bowing but at only 1/16" - I'm betting these pieces were stacked without stickering after you milled them or you left them laying on a flat surface where one side was exposed to air. The side exposed to the air this time of the year most likely dried out - very quickly. Take a sponge and lightly but evenly moisten the side which is the inside curvature of the "U" shape on one of the boards and let it rest overnight - face down and see if it doesn't go flat. If it's due to stresses it won't and may in fact worsen but if it is a moisture problem - or lack thereof on one side - you'll know soon enough. To correct the problem, sticker the wood - cupped side face down and let it rest for a day or two.

I'm not very fond of pulling wood into shape with clamps on a project where it's just as easy to correct the problem first rather than trying to force it.

Learn to sticker all layers after milling to rough cut sizes and again after milling to final sizes. That means the bottom pieces are not laying flat on some surface - they are also stickered.

Bob S.

[Jeff]

Your assessment is accurate: I live in an urban environment and we have satellite, not cable....

[Jay Pique]

seminars. I'll be there at least one of the days. JP

[John Grossbohlin]

Look me up.... I'll be wearing an NWA name tag.

John