Primitive Archer
Main Discussion Area => Bows => Topic started by: VicNova on December 16, 2015, 11:14:58 pm
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I just purchased some Ash lumber from the place I have always bought my lumber for bow building. In the past, the ash I have used from this source has always cracked or had crystals on the belly despite a proper tiller. This always mistified me and I had given up on ash as a good board lumber for making bows.
After gaining more experience, I thought to check the moisture content. This ash lumber comes in at 5-6% moisture content, the cause of my troubles. This is really odd because all the maple and hickory lumber I buy from this source has good moisture content of 9-10% and has always made great bows for me.
So the question is: What is the best way for me to re-hydrate this lumber. I would like the quickest method possible.
Please don't say "just let it balance to your environments moisture level naturally". The place I buy it from is in the same environment as me. I think it would've done that by now since it had been sitting at the store for quite some time.
Thanks
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Sorry to say it, but if that's what the moisture content is and the wood has been stored there that's the moisture level it's going to return to. You can store it in your bathroom next to the shower until its dripping wet. When you remove it from the bathroom it will start dropping moisture until it's right back where it is. Josh
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Any idea why the wood would be pushing so much moisture out? :o
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As far as I know, ash doesn't have the best compression strength, and needs to be designed accordingly. We'd need to see these bows with frets to determine what happened with them.
Compression weak woods will always show you their weak spots.
Wood loses and gains moisture very easily. I weigh my bow blanks, and sometimes they gain weight if it's been raining a lot
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Well those ash bows with frets are long gone. :P
It's just so odd that the ash pushed out all that moisture. All my hickory, red oak, and maple lumber never have such problems with losing or gaining excessive moisture.
I gave the wood a shower before I glued a handle on. Once I scraped it down to floor tilling thickness moisture was at 5-6% again (didn't go deep) . So I'm giving it another hot shower. I guess I'll find out.
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Every piece of wood reaches it's natural equilibrium. Its inevitable. It will take a week in the bathroom to gain moisture throughout the wood. However that effort would be futile since it will dry right out in a few days and probably have some nice drying checks as well. Overly dry wood usually causes tension failure not compression failure. If your having problems with chrysaling, you need to increase your dimensions and make sure you tiller it properly. Also ash responds very well to belly tempering. Josh
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Well, those chrysaling bows were done years ago and my tillering skills weren't as good as they are now. Maybe it was just me.
I guess I'll find out soon. I really hope I didn't just buy $60 worth of fire wood. ;D
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just curious as to how you are measuring the MC?
Also, some wood is dried more than others. what can your supplier tell you about the drying spec on that ash?
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I like 6-7 on osage. Don't build from ash though. I think less moisture would help with frets more than hurt. All you gurus correct me if I am wrong. These are my thoughts. Arvin
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Just a thought I have been kicking around a idea about Trapping the back on a hickory bow to balance compression/tension , might work out on board ash, never tried it just a thought
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I've never made an ash bow that didn't fret. That's why I rarely use it.
Wood is hygroscopic, meaning that it takes on and releases moisture to the atmosphere. It will hit equilibrium after a period of time, depending on the wood.
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Frets aren't from too dry wood. They are from poor design, poor tiller, or VERY wet wood. No other reasons bow wood frets.
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I'd add belly pin knots to that list Pearlie!
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Ash is probably the most inconsistent wood I have ever worked with. I have heard there are a lot of varieties all sold as just plain ash. If I can find pretty dense stuff about like hickory I will sometimes use it.
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Steve I bet the bad stuff is black ash or green ash. I think white ash (formerly known as up here) is fairly consistent.
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I made 6 or 7 white ash bows. All but one chrysalled.
It is weak in compression or I am weak in tillering. :)
Around here in NH the outside of wood gets to be about 5 or 6% but the inside is higher.
Wood will get into equilibrium with its environment anyway
That's unavoidable.
I agree with PD it is about the design and tillering.
Jawge
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Interesting.To add the reason some limbs fret can be the design is good and the tillering is good but the design is too aggressive or stressful for the type of wood.Maybe that's a rehash of what's said earlier but it's one way I look at it.
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Stickbowman and Pearl Drums nailed it for me. Super dry wood becomes brittle and would fail suddenly rather than compression fracture slowly.
And, while I agree totally that wood will, all by itself, settle in at a certain moisture content, i don't think you can neccisarily completely expect all wood in the same geographical area to be treated the same. what I mean is, say regarding your supplier, maybe he buiys ash from a different source, and it is cut, treated and shipped from somewhere else, and you are buying it before it really has a chance to settle in. Or maybe his source uses a hotter kiln and dries their ash faster, and so damages it,. Or maybe he keeps it in a different shed which is just slightly warmer, or gets more wind, and thus adjusts faster. Or, something. And since board bows are often bught and then made right away, ....... who knows.
Ash is NOT, despite it's hardness and numbers, as "good" a bow wood as woods of similar weights, I agree; like harder maple, white mulberry, and heavier elms. But it isn't TOO bad. Think wide and long, trap the back, toast the belly, etc.. and I bet you can do it.