Author Topic: Question about set and humidity  (Read 1203 times)

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Offline eastcreekarchery

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Question about set and humidity
« on: December 27, 2020, 07:59:07 am »
I'm working on a hackberry (whitewood) bow and over the course of the build it has taken about an inch of set. The inch of set is apparent after I unstring the bow (which is done tillering), but when left overnight laying on its back, it returns to 0 inches of set. The RH in my area is between 70-80%. Is the bow slow to return to 0 inches of set because of high humidity or might this be a feature of the wood being sluggish or both? Should I try to dry the bow out as much as I can or just to 6% MC then seal it ASAP? Thanks!

Offline Digital Caveman

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  • formerly Tradcraftsman, formerly Yooper Bowyer
Re: Question about set and humidity
« Reply #1 on: December 27, 2020, 08:06:34 am »
I wouldn't be happy with that kind of humidity at any temperature. 
God Bless America

Offline RyanY

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Re: Question about set and humidity
« Reply #2 on: December 27, 2020, 08:12:11 am »
I would guess a mix of both but 1” of set is not bad. Even if you dry it and seal it at a lower MC, no finish is 100% protective against moisture so it’ll likely rise to equilibrium over time.

Offline eastcreekarchery

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Re: Question about set and humidity
« Reply #3 on: December 27, 2020, 08:35:55 am »
I heat treated the belly so i think that should help the bow stay snappy in higher humidity. Many of the native Americans in my area were using whitewood bows so they must have still been effective hunting implements. Ive also heard of fire hardening the entire bow to make it hydrophobic and increase performance.

Offline Pat B

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Re: Question about set and humidity
« Reply #4 on: December 27, 2020, 09:52:46 am »
What is the humidity in your house? The outside humidity won't adversely affect your bow if it is in a controlled environment.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline eastcreekarchery

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Re: Question about set and humidity
« Reply #5 on: December 27, 2020, 10:44:00 am »
Ill have to pick up a humidity meter and see pat

Offline willie

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Re: Question about set and humidity
« Reply #6 on: December 27, 2020, 10:10:38 pm »
unless you buy an expensive hygrometer, knowing what the weather service reports for humidity and temperature,
and adjusting the humidity for the room temp will give you a better idea than the inexpensive meters

Offline willie

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Re: Question about set and humidity
« Reply #7 on: December 27, 2020, 10:56:22 pm »
in the chart below
find the outside temp on the bottom of the chart and go up until you get to the curved line that matches the reported outside humidity

trace a level line to the right until you get to the inside temp, and estimate the relative humidity at the new temp

example: entering the chart at 40 F and going up to the  80% RH line , indicates a level of moisture that is about 25% RH in a 72 F. room
« Last Edit: December 28, 2020, 04:08:26 pm by willie »