Click to enlargeStress Relieving Maple<BR>Valuable Info You Should Know

The information contained on this page, in our opinion, 99% of cue makers do not know. We've held it to ourselves for years but decided to make it public as an informed consumer is our best customer. Another reason is because cue makers always ask why our shaft wood yields a higher percentage of usable shafts -vs- our competitors shafts. Well, the reason is properly dried shaft wood - 'stress relieving'. When you hear every cue maker talk about buying stress relieved maple for their shaft wood, just remember where you read it first. :-)

Most cue makers do not have any idea of how and why Maple warps, twists, etc. They have their opinions and some are correct but they don't deal in Maple to the extent that we do nor do they see the quantity of Maple that we see nor have they cut the quantity that we cut. They are cue makers who make cues and not wood sellers and producers of fine shaft wood. As being both suppliers to the trade and producers of high quality shaft wood, it is our business to know what makes the best Maple for our needs. Years of strong relationships with Maple mills produces the quality wood necessary for our needs.

There is much conversation about flat sawn -vs- quarter sawn maple shaft wood. And there is much conversation about 'vacuum' dried -vs- 'conventional' dried maple. In our experience of cutting and doweling thousands of board feet of maple, we do not believe there is much of a difference IF the Maple is properly dried (keyword = properly). As many cue makers agree, once a shaft square is turned round it would be difficult to differentiate between flat sawn and quarter sawn. The difference is if the wood is NOT stress relieved. We have been dealing with our suppliers for many, many years and have come to trust them for supplying superior kiln dried Maple for our needs. We have purchased wood from other suppliers and the difference in their flat sawn was considerable in that the wood moved when turned round (an expensive lesson). We have never had this problem with our regular suppliers and as such have remained loyal. While most of our shaft wood is quarter sawn we do occasionally get regular shipments of flat sawn that IS stress relieved. That's the difference! And now... what is stress relieved. Please read on...

What is STRESS-RELIEVED lumber?

ALL lumber that is kiln-dried correctly (keyword = correctly), SHOULD have a final 16-hour stage of kiln-drying of higher humidity. That is, after lumber in a kiln has reached a target moisture content of, say, 8% (this can take 4-6 weeks), it is common practice (with good kiln operators) to increase the relative humidity for about 16 hours, before the lumber is taken out of the kiln. This final blast of higher humidity in the kiln, in effect, "loosens" the wood fibers on the surface and relieves internal stresses (an extreme condition of this is called "case hardening").

You can see the EXACT kiln-schedule that a kiln operator should use for hard maple (Sugar Maple); it is a 7 stage process (based on moisture content), and note that this final 16-hour period is not included. Pick common name and then pick Sugar Maple

How to CORRECT stress-relieved lumber...

If lumber is not stress relieved, it can still be "corrected" by placing it in a high-humidity chamber for about this same 16-hour period. We believe, that this would increase the moisture content by about 2% (overnight), but we know that it would be stress relieved.

============================================================== This is all good to know, but how do we KNOW if lumber is stress relieved? ==============================================================

How to TEST for stress relieved lumber.... If you have 5/4 lumber.....take a 6" wide board and cut 3" of length. You now have a 5/4 thick (1-3/16") by 6" wide by 3" long block. Take a band-saw and cut slits along the width (and parallel to the end-grain) of the block, as if you are making a finger-board (or tuning fork); the end-grain of the board should be facing up (see photos at the top of this page).

At room temperature, room humidity:

1. If the fingers remain straight for over 8 hours, then you have well-dried lumber (does not matter whether it was conventionally kiln-dried, vacuum kiln-dried, or slow-roasted over an open fire) ;-) other words, the end justifies the means.

2. If the fingers IMMEDIATELY warp, then your lumber is not stress relieved and it has a large amount of stress inside.

3. If the fingers take about 8 hours to warp, then it was not stress-relieved enough; small amount of stress inside (did not warp immediatley, but slowly warped).

Take a look at the pictures on the top of this page, and you will see exactly what we mean. Left is properly dried (stress relieved) and the right one is not stress relieved (improperly dried). This is the perfect example why shaft wood warps.

All this is pretty exciting. A lot of cue makers feel 'vacuum' drying is the best. We've dealt with 'conventional' dried Maple for years and feel that 'conventional' produces better wood. The 'vacuum' process is attacking the molecular structure of the Maple and creates a lighter (in weight) wood when dried (and we believed more porous too). We believe that this is support of our "argument" that vacuum kiln-drying is not the only "good" drying method for shaft wood. We've always supported conventional kiln drying is just as good and better than vacuum drying. It just has to be handled correctly. Now we have a test to prove our point.

And that's our 3 cents.. :-)

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