stress relief for 3D carving

[gary_n]

I have cut a 3D project from 3/4" hickory and the piece is now bowed from one end to the other. Will stress relief on the back side help? What kind of cuts and/or how many and how deep would you make them? V-bit cuts or just straight endmil type cuts? The project is 4" tall and 84" and 60" long (there is 2 pieces).

[dlcw]

Gary,

Since it looks like you live in TX here is what I would suggest. On a sunny day, take your boards outside, lay them in the grass with the bowed side up. What this does is causes the concave side to absorb moisture (expand) and the sun to dry the convex side (contract). This will straighten the board. I've done this hundreds of times with wood that is cupped and/or bowed. Never had a situation where it didn't work.

My only problem, where I live, is that this process only works about 7 months a year as the other 5 months there is snow on the ground. :)

[gerryv]

Without wanting to hijack the thread, Don, that sounds really interesting and would be great news. Does the bow not then just come back all or mostly as soon as the water content rebalances through the timber?

Okay, back to your question Gary.

[dlcw]

Once the redistribution of moisture in the wood takes place, I have not had a piece spring back on me. On some pieces you might have to let it sit longer to start warping/cupping in the opposite direction a little. The very small amount of spring back will return it to flat.

[myxpykalix]

This has been an issue I have had to deal with, mostly unsuccessfully. I have used 8 year old air dried wood and others and when you scoop out too much wood it cups on me when my resulting base (wood not carved into) is 1/4" or so. The one thing i have done is to leave the carving extra thick 1/2" or so.

I have also tried cutting kerf cuts into the center along the curve and tried to leave a heavy weight on it to relax the wood to no real result.

[ssflyer]

I've done a lot of projects with oak flooring, and it seems very stable. Just looking at a piece, it appears that the relief grooves cut into the back are about 3/32" deep with about 1" spacing...

Ron

[gc3]

http://www.woodweb.com/knowledge_base/Humidity_Temperature_Wood_Moisture.html

http://www.cpadhesives.com/wood-moisture-content

http://www.woodweb.com/knowledge_base/MeasuringMonitoring_Moisture_Levels.html

lots more info with google search...woodweb has a lot of info on this subject both from cnc machining and traditional fabrication tools.

[Gary Campbell]

Gene...
Thanks for posting. Great reading.

[cabnet636]

it helped me out a bit this week, when the cupping took place it caused the wings to "spring" forward and look at the flute in the anchor, we glued the "rope" up in 1/4" strips and is is as flat as a _______

[englert]

Nice! You certainly did this on a grand scale. Nothing to add about the problem, just like the project.

Semper Fi,

Dennis

[cabnet636]

one big EGA !!! it will hang in an "O" club on the east coast

[myxpykalix]

O..is right, as in O man that is fantastic. How long did that take to carve? My guess is over 20 hours? Beautiful work.

[loriny]

That is a thing of beauty. I am impressed.
Lorin

[cabnet636]

total 12 hours (large ballnose) if you look close the depth is 4.5 inches the belly of the globe and the bird are 1.5 inches and the rest at 3inches, i used the aspire slicing feature as i could only find 3" thick walnut at 7% moisture content

[myxpykalix]

" i used the aspire slicing feature as i could only find 3" thick walnut at 7% moisture content "

I have some....how much you want? We just put some in the kiln (actually we just didn't bother to take it out when we loaded the maple) and it was 7% when we put the moisture meter in it.

We were planning to cut down and load some cedar in next but i was trying to talk her into doing some more walnut.