Author Topic: Moisture content of wood for bow making  (Read 6418 times)

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Offline Mace-McLatchie

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Moisture content of wood for bow making
« on: June 04, 2018, 11:56:52 pm »
I'm fairly new to the craft of bow making. I've made a few and broken them all. I'm cheap and don't like to spend money if I can make it work with what I've got. Several years ago a made a few bows out of various woods but all pieces of kiln dried flooring; Ipe, Hickory, Bamboo. I used to do floors for a living. Like I said before they all cracked after a fair amount of usage. They were about 60# at 27 inches. Well, I'm at it again and this time using Vine Maple I harvested here in the PNW. I can't help but think all those other bows cracked because of the kiln dried wood. And probably some of my tillering skills or lack there of. So finally here is my question:
Does anyone know the ideal moisture content of wood for bow making and maintaining the flexibility over time?
Side note; I also have 1940’s vintage Ben Pearson Hickory child's bow “Cock Robin” that I want to refinish and try to shoot but I'm afraid it will crack unless I can bring the moisture content back up.

Offline TorstenT

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Re: Moisture content of wood for bow making
« Reply #1 on: June 05, 2018, 02:48:39 am »
The moisture content of wood (I think it’s called equilibrium moisture) depends on the ambient temperature and relative humidity. Kiln dried wood is far too dry, but might still work as bow wood, if you store it (as well as your finished bows) appropriately and give it time to rehydrate and balance out.
There are tables available in the WWW helping you to find out the equilibrium moisture of wood, using the respective room temperature and air humidity in your storage. You should get a hygrometer and look it up in one of those tables. Most bow woods need around 8 or 9 percent of relative moisture. Too moist and it will take too much set, too dry and it will break. Hickory for example can handle only 5 percent of equilibrium moisture.

Offline George Tsoukalas

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Re: Moisture content of wood for bow making
« Reply #2 on: June 05, 2018, 07:05:50 am »
You sound like you have a moisture meter?
I like 6-8% for hickory.
I like 8-10% for all other woods.
Kiln dried wood is fine for bows as long as the grain is straight tip to tip or nearly so.
More on my site.
http://traditionalarchery101.com
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Offline DC

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Re: Moisture content of wood for bow making
« Reply #3 on: June 05, 2018, 10:53:19 am »
I shoot for 45-50% RH where I store my bows and staves. That's probably too moist for Hickory but I don't have any of that.

Offline aaron

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Re: Moisture content of wood for bow making
« Reply #4 on: June 05, 2018, 06:47:00 pm »
Where you from?
Ilwaco, Washington, USA
"Good wood makes great bows, but bad wood makes great bowyers"

Offline Nasr

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Re: Moisture content of wood for bow making
« Reply #5 on: June 05, 2018, 07:37:13 pm »
99 percent of the bows i make are board bows from lumber stores and ive made several bows that still shoot today. If you are breaking bows i would first look at the board and make sure its good enough to make a bow out of if that is good then everything else has to do with me. If it fails i would look to see if i tillered it correctly.

Offline Mace-McLatchie

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Re: Moisture content of wood for bow making
« Reply #6 on: June 05, 2018, 07:40:33 pm »
Portland, OR

Offline Mace-McLatchie

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Re: Moisture content of wood for bow making
« Reply #7 on: June 05, 2018, 08:02:34 pm »
First off thanks for the tips and advice!
I’m sure it’s a multi issue problem. Tillering, wood selection, moisture content.
 I asked the moisture content question because I just cut a stave of Vine Maple and it is drying so I was looking for the best moisture Conner to achieve before I start cutting and scraping.
As far a wood selection I’ve been trying to use pieces that have a continuous grain from end to end without any running off the edges.
The Vine Maple I have is not very thick in diameter like 2-3 inches so not a lot of wiggle room there but what would you all suggest for larger pieces as far as the cut on the grain? Plain, quarter or rift? Should the bow always include the outer rings as in the first cut or two off of plain sawn?

Offline aaron

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Re: Moisture content of wood for bow making
« Reply #8 on: June 05, 2018, 09:01:07 pm »
Welcome from Ilwaco WA . I live 1.5 hrs away at the coast.
You will never have wood that is too dry if you live in portland.
If you are cutting your own wood, dont saw but split.
For a 3 inch vm, reduce to a half diameter by splitting right down the pith.Then  dry for the summer and youre ready to go.
ALL VM bows will have the outer ring as the back.  Most woods are like this unless  backed.
Ilwaco, Washington, USA
"Good wood makes great bows, but bad wood makes great bowyers"

Offline Weylin

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Re: Moisture content of wood for bow making
« Reply #9 on: June 05, 2018, 10:03:48 pm »
You're in a good place for bow making. You're surrounded by great bow wood and great bowyers. I lived in Portland for years, now I'm in Willamina but I'm moving to NC this summer. Look up Rose City Bowyers on Facebook. It's a great group of people with a lot of expertise. As for bow wood, look for vine maple, ocean spray, hazelnut, and pacific yew to name a few. vine maple and hazelnut can get dried out fairly fast if they're treated right. You could have some quality wood ready to work by the end of the summer, easy, if you cut it now.