Cues Staying Straight
Fast Lenny,
You're on the right track in suspecting that changing moisture content can cause cues to warp.
This will be a fairly long read.....my apologies for that.
As it relates to wood, the term "moisture content", is a comparison of the weight of the water in a piece wood to the weight of the wood fibers themselves. Generally speaking water is heavy, and wood fibers are light, so the weight of the water in a wet board can be more than the weight of the wood fibers. Thus, in that particular board, the "moisture content" may be 125% or 150%.
So, if we say a piece of wood has 10% moisture content, then that means that the weight of the water in that piece of wood amounts to ten percent, or 1/10 of the weight of the wood fibers piece of wood.
Freshly sawn wood (referred to in the industry as "green") straight from the forest has a very high moisture content, and will begin to lose that moisture to the atmosphere immediately. Green wood must have a great deal of that water removed before it can be used for most purposes.
The manner in which the moisture content is slowly dried out has a great deal to do with the quality of the wood once it reaches a suitable level of dryness. Wood that will be used to frame a house is usually dried to about 16%, while wood that will be used for cabinetry will be kept in the dryer until it is down to 6% or so.
Now, "relative humidity" as the weatherman explains it, is the amount of water air will hold at a certain temperature before it starts to condense (rain or dew). Warm air will hold more water than cooler air. Thus, the "relative" aspect refers to the effect of the temperature. The actual volume of water in a given volume of air is different than "relative humidity".
Relative humidity for any given locale can change dramatically from day to day. It is the average relative humidity over extended periods that will have the biggest effect on your pool cue. Your cue, like all wood that remains in an environment for an extended time, will absorb or lose water until it reaches a state called "equilibrium". That is the balance point, so to speak, between the amount of water the wood will naturally contain versus the amount of water in the air. Generally, a cue that is in equilibrium in Miami will have a higher moisture content than a cue in equilibrium in Phoenix.
Now, when wood fibers gain or lose moisture, they will gain or lose weight. There will be some swelling or shrinkage as well. That swelling or shrinkage is what causes the warpage and cracking in cues.
Wood that was properly dried when it was first taken from the forest and sawn is more likely to be able to resist warpage due to moisture content changes. The care and process taken to properly dry and store fine wood is one of the reasons it costs so much as compared to a regular old two by four down at the lumber yard.
One way to tell if your new cue is likely to warp, is to measure the moisture content of it versus the moisture content of cues that have been in your area for a couple of years. Almost all cabinet shops or wood floor installers will have a handheld electronic moisture meter. It takes about one minute to calibrate the meter and measure your cues. If there is a difference of several percent, you might have trouble in the future.
Although wood has some degree of elasticity, it can be permanently bent to a desired shape by industrial steam processes. Unfortunately, few persons have had any luck whatsoever in straightening a bent cue shaft.
Although it is difficult to protect your cue from climate change, you can lessen its vulnerability. The butt, of course, has a finish that helps protect it. Your shaft, though, is usually only finished a few inches down from the joint. Keeping the shaft burnished will help a lot. That will flatten the hairy little wood fibers that protrude from the cue and act like a sponge.
Due to the process by which wood absorbs or loses moisture, a very vulnerable part of your cue is where any "end grain" could be exposed. That would be at each end of both the shaft and butt. Again, the butt is pretty well protected by the butt cap and the joint. The business end of the shaft is protected by the ferrule. However, there will usually be some end grain exposed at the joint. A joint protector for your shaft may be a wise purchase, as a tight fit will help keep that end grain covered.
Again, I sincerely apologize it took so long to expain the issue.
Cheers.
Joe
