Building the wood arrow....pt. 8 Moisture control

      By now, many of this Blog's readership may be attempting to build some good wood arrows.  We've discussed all the steps to make them well...and discussed the wood arrow finish, but here's a little more insight to what I think is an overlooked item.  Humidity.

      From sending bows all over the U.S. and overseas, I've been made aware of the water absorbing nature of wood and grass (bamboo) and it's affect on bow poundage.  Bows made in the dry western climate of southern Idaho will get softer and lose 2-3 pounds when exposed to high humidity, high temperature areas of the Eastern or Southeastern seaboard, or even in the Midwest.  It's well known among bamboo flyrod makers that even with a good varnish coat, bamboo rods will absorb moisture and get soft and extra bendy during exposure to excess humidity.  Selfbow makers are relearning how Hickory can really absorb moisture unless its heat treated (tempered).  But no one talks about moisture with wood arrows...how come?

       In the old days when Cedar was king for arrow making, moisture control was taken for granted. Cedar (Lawon's Cypress) has a high oil content which repels moisture to a good degree.  Compressed cedar (Forgewoods) were highly regarded for strength and durability because of the oil content aiding in the compression of the wood cell structure.  But what about fir, spruce, hemlock, pine, hickory, birch and bamboo arrows?  Well, to put it bluntly, they all will absorb moisture to some extent, and that affects durability, arrow spine and more importantly, arrow recovery through paradox.

        It's been said of the slower or faster recovery rates of some wood arrow materials.  Opposite of Cedar, Hickory and bamboo are probably at the extreme end of slow recovery, unless they are heat treated due to their great water absorbing qualities.  The other woods fall somewhere in the middle.  My experience with hardwoods was that once I had them shipped to the dry West, they would warp horribly as they dried out and stabilized.  They took a lot of care to keep them straight, more than I wanted to endure.  As an arrow absorbs humidity, it gets slower and more "loggy" in its' recovery and will retain bends in the shaft from undue flexing.   Certain woods absorbed water more quickly, requiring more care.  I don't seem to have that problem with fir, pine and spruce. Hemlock does absorb moisture and get softer in my findings.

       There's lots of advice for straightening arrows using heat, and I think that for the most part, it is good advice.  Especially if you're using an arrow from a humid area.  Allowing the shaft to acclimate to your local humidity level before straightening the shaft is a good idea...but what if you're living in the Midwest or East coast with 90% humidity? How much will it dry out, and how much will it rehydrate? Short answer... A lot.  You can heat straighten a shaft and seal it and two months later it will be softer and more bendable.  I believe this is where the notion comes from when archers say they "shoot the spine out of the arrow".  I personally don't think shooting will do that but I do believe that shooting an arrow that has a high moisture content can get a softer spine as the paradox stresses are being inflicted on a softer material.

      This shows once again the importance of shooting a Hill style longbow (non-centershot) with a flexible shooting style, relaxed bow arm and dynamic release...all which allow the bow to move a little, or not, to allow the passage of the arrow across the bow as we've discussed previously.  It helps with the variables of arrow shafts from day to day, season to season.

       So how do we control the moisture as well as possible?  Well, for starters, I think that we should "dry out" arrow shafts before any straightening occurs, whether you heat and straighten, or dry out for a while in a controlled area before any straightening happens.  If you live in an area with 30% humidity, it's not as important as if you live in an area with 90%.  But get the shafts dried out as best as possible for a bit before straightening them, and then once you do, get them sealed asap.  Once sealed, it will help keep them straighter, longer.  Use a good finish.  For this reason I'm not totally sold on Acrylic water-based finishes.  I've made my share of arrows with them, but I've noticed in extreme conditions, like leaving an arrow under the grass in the lawn for a few weeks, the arrows will get very soft and bendy, requiring me to dry them out for a few weeks before attempting to straighten them.  Arrows thusly left in the same conditions with oil-based enamels or polyurethane finishes have fared much better for me.

      I know those are extreme conditions, but they give good examples of what to be aware of.  Over time, just like the bamboo flyrod makers discovered, humidity will still penetrate a good finish and affect the bendy-stiff properties of bamboo. It stands to reason that wood arrows would be similarily affected.  So we need to be aware of the tendency, and dry out arrows once in awhile, especially if you're finding that your arrows aren't really staying straight, or they seem to have lost their spine.  Before any work is done on them, dry them.  Put them on the dash of a car in the sun, or on a heater vent in the house in the winter, or something, but do it for a few days...then check them and straighten as necessary.

      Wood arrows require a little more maintenance than other shaft materials, but like all things of naturally organic materials, that's part of the allure.  So dry them, seal them really well, and check them often by flexing and noticing if they recover from the flexing or want to stay a little bent. That's a good way to test how much moisture they may have absorbed.  Keep your arrow moisture under control...you who live in humid areas, and you will be more able to

      Shoot Straight.