Grain orientation for dovetails

This thread???  *LINK*

Andrew F in Australia

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http://www.woodcentral.com/cgi-bin/handtools.pl?frames;read=99321

IDIOT

Donald Pierson

>...that is what I recall reading somewhere...IDIOT...Inside Of Drawer Outside Tree

Re: IDIOT?

Donald Pierson

>or is it Inside Drawer Inside Of Tree...I am sure someone else will set you straight...Happy New Year

Re: IDIOT?

Andrew F in Australia

>Hi Donald,

What I found interesting from the discussion that I linked to above is that US practise is the opposite of European/Australian, in that wood is dried bone-dry and then allowed to reacclimatise.

Which part of the tree lives on the outside of the drawer depends upon the wood moisture at the moment it's made and the average moisture content in the environment into which it is going.

The IDIOT acronym reflects European training,in which timber is used at a couple of percent higher than equilibrium moisture, so further shrinkage/distortion is expected.

There is no magic solution. But, if you want to stick with tradition,

stick the heart of the tree on the outside of the carcase.

THe whys and wherefore's are in the link that I posted above.

Cheers,

Andrew

More Myths. Orient for best looks

bill tindall, E. TN

>There are all sorts of these wisdoms and myths that in my experience provide no value and usually detract from appearance. We can add ripping wide boards and alternating grain in glued panels to this list. Perhaps they started in days when cabinet makers used lumber that was air dried-more or less. I have furniture made from wide boards and I don't see any tendency for the boards to suddenly decide to become not flat. I have wide boards in storage and I don't ever see them after 1-30 years suddenly deciding to assume another shape either.

I think the reasons these precautions are unnecessary in properly dried lumber is as follows: Properly dried lumber is stable and only moves small amounts in response to ambient humidity changes. It only takes a small amount of force to flex a panel across its width. If the furniture panel is constrained from flexing by normal joinery it will be held flat during typical humidity excursions.

Experiment. Suspend a 18" panel between two points at its edges. Push on the middle of the panel and see how little force is needed to flex it across its width. This same small amount of force provided by joinery will hold it flat in use.

Go forth and use wide boards in their most attractive way.

I would like to see that cherry board, rare as they have become, preserved in an attractive piece of furniture rather than a utliitarian tool chest.

Your post reminds me of Tage Frid's advice,

Bruce, a MN Galoot

>to just orient the wood for the best appearance - that is, instead of trying for some theoretical orientation of growth rings. I have followed Frid's advice on wide glue-ups and have never had a bad experience. Sounds pretty much like your experience.

Bruce

Re: IDIOT?

Donald Pierson

>Andrew,

I forget rules faster than I learn them. It was past my bedtime and couldn't remember what or where I read the rule. Rules are like your doctor and horse-shoer...they are as good as your belief in them. Don in cold below freezing Vancouver,WA(not West Australia),USA(not Canada)

Inside (of) drawer IS outside of tree

Bill Houghton, Sebastopol, CA, sorta cold

>that's how you can get to the acronym. As usual, the acronymerologist ignored a word when it was necessary.

Re: More Myths. Orient for best looks

Adam Cherubini

>I think the term myth is too strong a word choice here. Its dismissive.

As I understand it, if you orient heart side out, the boards seek to pull apart in the center of the joint where it can best be reacted. The other way around is much more difficult to react.

I think Bill's point is really that the extent to which this happens or is a problem is debatable- but that doesn't make it a myth.

The dismissive side of this is that Tage Frid didn't live long enough to see his pieces fall apart. That Bill hasn't seen this problem doesn't mean it won't occur in the future. There is no 100 year old furniture put together with yellow glue and biscuits. Consequently, I try to build most things with the notion that the glue does nothing. Heart side out is an example. Of course I do use glue and my glue is very strong and will be for many decades. This is also what folks did 200 years ago.

That said, it seems to me that the furniture that has survived for centuries did so because of ease of repair and maintenance, not best practices.

That's my 2 cents anyway

Adam

Re: More Myths. Orient for best looks

Andrew F in Australia

>Hi Bill/Adam,

There's some method in the madness, Bill. Bear in mind that modern glues creep - they won't hold any tensile forces for more than a few years. I'd rather wok with nature than against it.

It's about controlling the cup and the direction in which it goes. As I hinted at, changes in humidity do change the cup in a board.

Here, timber's dried to 14% and sold, when final equilibrium level is 10-12%.

So, in this case, as with Tage Frid, you put the heart side outwards. Depending upon where you are in the US, the timber you buy maybe at 8-10% moisture and the object may be located in an area at 12% moisture. In this case, Tage Frid's advice is opposite to what you need to do.

Another practical example is that you need to have the outside board on a table built so that the board cups down hard against the table rails. If the board cups up, you get a visible gap that spoils the appearance, more so if the item's at eye level so it's clearly seen.

Enjoy the New Year

Cheers,

Andrew

classic typo .......work with nature .........

Andrew F in Australia

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It was all that talk of the orient that did it...

Paul Kierstead

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boom boom...

Andrew F in Australia

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Has anyone ever seen a cupped...

bill tindall, E. TN

>drawer side or blanket chest? (no doubt encouraged by this challenge someone will have seen one, probably made from not well dried lumber) I rest my case that such panels are so flexible about their width that the joinery will hold them flat, yielding the benefit that one can put the best board face where it is most visible. Fretting over this and other trivia just distracts woodworkers from more important issues.

I have not experienced any detectable cuping of properly dried lumber in response to humidity changes so long as both sides of the lumber are similarly exposed to the humidity change. I do agree that differential changes in moisture content across thickness will induce cup, though it will be easy to resist with good joinery.

I recently tore apart a cabient that lived in our vans from 1970 till about 2000. It traveled to nearly every state and spent significant time in dry Wyoming/Montana summers and wet TN winters. The 8" drawer side (poplar) and the 13" glued panel doors (ash) remained flat and the drawer joints sound. All the wide (up to 18") boards in tops and sides around the house stay flat too.