Hickory and heat treating

[zinger]

I had a couple of questions about hickory and heat treating. One - just how effective is heat treating when it comes to checking one of hickory's greatest flaws, it's absorption of and response to moisture? Does it stop these tendencies just a little, a lot, or maybe even completely if done right? Also, I have just cut a good number of staves from a nicely-grained hickory board I bought. This wood has been kiln dried. Will this fact in itself make a big difference in keeping moisture out? Keep in mind that I don't have a moisture meter, so I can't determine where the wood is at at any given point.

[Starfire]

I have the same question too working on a Hickory bow right now.

[dbb]

Heattreating will make the poundage go up a bit,but i dont see any difference in moisturepickup on my hickory bow.(also kiln dried)
It will still get a bit sluggish after a longer period of high humidity.So to keep it snappy,seal it well and store it in a good place between uses.

/Mikael

[Adam]

Would it help to heat treat and lower the moisture content, then seal it with a waterproof or resistant finish?  That seems to me that it would keep moisture from getting in, or at least slow it down.

[Pat B]

All woods and especially hickory are hygroscopic, meaning they take on and release moisture to the atmosphere. You can not stop this transfer of moisture but you can slow it down with a good finish...but even then high humidity will affect wood bows, especially hickory.
  If you keep your bows stored in a controled environment, ie inside a heated or air conditioned house or in a hot box, you can nontrol the M/C of your bows somewhat.
 Heat treating will give hickory better compression strength, its weak point so it should help with performance some during high humidity times but I've never tested this.

[smoke]

I heat treated a hickory stave last winter and it has held up well.  That isn't to say that it doesn't pick up mosture but I heated in about 2 inches of reflex and after a hot, humid summer and lots of shooting it still holds 1/2 an inch of reflex.  And I will confess that I am a really bad bowyer so if I got good results . .  .

[zinger]

I do realize that all wood to some extent will absorb moisture and this is something I have clearly seen while shooting some of my RO bows on hot, humid days. Apparently, though, with hickory, it goes beyond the pale and can actually cause signifigant set if you string and shoot it at such times. Seems so sad that a bow wood that works so awesomely during the right conditions should be so hampered during the wrong ones and those so typical to the regions where it grows. Seems to me bowyers would hardly use much else if it didn't have this problem.

Well I'm hoping to get a moisture meter and take a look at the problem as I have a bunch of nice staves from the hickory board I bought. Maybe I can come up with some new idea to combat this.

[Starfire]

Would something like Waterlox Marine varnish work well for keeping out the moisture.  I have some and was thinking of using it, though not sure how it will hold up to bending.  It's used on wooden boats so I would imagine it would lock out moisture.

[tom sawyer]

I don't think any finish is going to prevent the equilibration of wood to ambient humidity over the stretch of weeks.

As for heat treating hickory, its already a bit brittle and prone to chrysalling.  I think heating makes it more brittle.  The upside is it makes the wood slightly stronger and you can make it a little thinner as a result.  There are so many things that go into a bow's design that affect whether its overbuilt/underbuilt/just right, that you really can't know until you build it, whether its going to work or not.

[DLH]

All woods and especially hickory are hygroscopic, meaning they take on and release moisture to the atmosphere. You can not stop this transfer of moisture but you can slow it down with a good finish...but even then high humidity will affect wood bows, especially hickory.
  If you keep your bows stored in a controled environment, ie inside a heated or air conditioned house or in a hot box, you can nontrol the M/C of your bows somewhat.
 Heat treating will give hickory better compression strength, its weak point so it should help with performance some during high humidity times but I've never tested this.

Just curious Pat I have seen where you have used rendered bear fat to finish your bows. How do you think this compares to other finishes to slow down the transfer of moisture? Also is bear fat a better then say deer fat or other rendered fats to slow the moisture transfer?

[JW_Halverson]

I am not altogether sold on the idea that a hickory or red oak bow shot on a hot and humid day will take permanant set.  My first bow was green ash and a snappy shooter in dry climates.  One weekend I went to the eastern part of South Dakota for a fantastic Rendezvous.  Great fun had by all and I even won a third place one day in the archery shoot.  But in the 100+ degree heat and 80% humidity I was actually able to unstring the bow just by pushing the loop off the nock! 

I was heartbroken, my good bow now drew about 20 lbs and had 6 inches of deflex!  Waaaaaah!      Two weeks later, after coming back to equilibrium it was back to 43# of draw weight at 26" and had no appreciable set.  I think part of that was because the bow was overbuilt by a few inches of extra limb and partly because picking up moisture in the cells causing them to be more flexible once again. 

I think this is something that might bear a little testing in a more controlled situation. 

You cannot really lock moisture out of the bow, but how you store the bow when home from the field can help you keep it a "zinger" and not a stinker. 

[H Rhodes]

JW, how long was your bow exposed to the heat and humidity before it started to act like a wet noodle?  I am curious how long it takes, since I live down in the hot, humid south.  I have made a couple of hickory bows and I keep them indoors in the air conditioning.  I will take them out and shoot them occasionally in the back yard, but then it's right back indoors where they are stored.  I haven't noticed much fluctuation in poundage or performance with mine, but then again, I haven't left them in a hot vehicle or out in the elements for any extended time.  Most of my hunts usually consist of no more than four hours or so, before I am back at the camp.  I have never been one of those sit in the stand dawn to dusk types.... maybe I lack dedication.    I am curious about the time frames involved before a bow can start to lose cast.... 

[JW_Halverson]

JW, how long was your bow exposed to the heat and humidity before it started to act like a wet noodle?

I arrived in late afternoon and the next morning I was shooting.  Noticed I was shooting low all the time and when I unstrung by noon I saw a good 3 inches of set.  The next morning it had recovered some, but an afternoon of shooting and I was full-on with the 6 inches. 

Your mileage will vary. 

[JonW]

On the last hickory bow I made I used Marc's method of heat treating. I don't know all the science behind it but I do know it works SUPERBLY. I shot the bow in a light mist one day and another day in a good rain. Could not tell any negative affect from the rain on the bow.

[Pat B]

DLH, bear grease does a good job of repelling water but as long as the wood breathes the transfer of moisture from the atmosphere will be there and no finish will prevent that. Any grease, bear, deer, pig, etc, will work on bows. Bear grease has always been considered the best of the animal fats by many folks and peoples.
  I have hunted downpours with a hickory bow with no negative results. It takes a while for moisture to enter any wood. I think in JW's example the heat and humidity played in the loss of performance and obviously no permanent damage occured as his bow came back to its old self after time in a proper invironment.
  Lenny, I have to disagree with you. Heat treating hickory does improve its performance. By increasing the compression strength it really helps the performance. Whether it prevents or delays the affects of moisture I have not done a proper study so it is only observation.