Tension lumber

I've heard about tension in lumber before, but have never had it happen to me prior to this instance. First the project, then the question. I made a shadowbox frame from curly koa -- frame is 16x20, 2 inches deep and 1 inch wide, I cut these pieces from a block that was about 40x9 and 2 inches deep. after I cut the miters and glued everything up, noticed that when laid it on a table, the frame was not flat -- had earlier cut two pieces off the original board for my son in law, and when I mentioned this problem to him, he remarked that he had the same problem with wood from that board.. Now my question -- the frame looks great and would like to salvage it -- is there any way I can overcome this defect? When I lay the frame flat, one corner is a bit over 3/8 of an inch off the table.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Herb Robinson wrote:

... wrt to reaction wood on 16x20 frame...

I know of no way other than restricting a piece of reaction wood from moving by another piece strong enough to overcome it, unfortunately. The only way you'll get around it w/ that particular piece of lumber will be to cut pieces sufficiently oversize and let it move before final milling.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Did you resaw the wood from 2inches into two 1inch thicknesses, or did you just rip 1 inch pieces off the original board? Did you find the board curving or twisting as it came off the saw (this is pretty obvious as it happens)? Did you allow the wood to acclimate to your shop for at least a week, before and after you resawed/ripped it (especially resawed)? It's also possible you introduced the twist when gluing up the frame, depending on how you clamped it. Unfortunately, I can't think of a way to salvage the frame short of cutting apart the joints, jointing and planing the wood as needed, and regluing it, slightly smaller of course. If you decide you have had it with that wood, I'll pay shipping to my house! ;)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I ripped one inch pieces off the original board -- the original board had been in my shop for some time. I did not see anything unusual when ripping the board, but then I wasn't looking for any problem either. I worked the pieces that I ripped and glued them up within an hour or two. I doubt if the twist was induced when doing the glue up -- although I've read about this problem before, it's the first time it'd happened to me -- a real bummer! Thanks for the input.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Herb Robinson wrote:

...
That's unlikely to have been reaction wood that caused the problem then...more likely uneven moisture movement. Allowing acclimization of the pieces prior to final milling would probably have alleviated the problem.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
What you might try is to find some angle iron and see if you can slot the frame on the back side and then screw the angle iron to the frame.
--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Compression wood", at least in softwoods is one or two tight growth rings that compensate for abnormal growing conditions, i.e., the tree grows on a steep slope etc... again, in soft woods it is readily identified as an extremely dark ring, and I suppose the same in other woods. When the tension in the tree is released, there is still compressed wood that makes for a tight ring. Sometimes, if you can identify the ring, you can rip on either side and the board will eventually straighten out (usually your just screwed tho..).
Sorry, sounds like a nice project... Schroeder

a
off
is
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.