Primitive Archer
Main Discussion Area => Bows => Topic started by: medicinewheel on December 19, 2010, 10:43:25 am
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Well, Tuesday I broke the little elm recurve I was working on, yesterday I broke an almost finished hickory backed hickory flatbow. Not the best week I had in bowbuilding.
The only reason why the latter one broke that I can possibly imagine was too low a moisture contend. Humidity's been down to 35% for a few days now. The bow broke unmotivatedly right through the middle of the lower limb, flawless pieces of wood glued together, no splinter had lifted, no glueline had failed, draw weight was <40# at 22", I pulled a little further, felt a sudden stacking and baaang it went. I could not even identify where the failure had started.
I know it's been discussed before, but I never actually considered it to be a problem:
What's the lowest possible humidity for building bows?
How do you guys deal with low humidity?
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Frank sorry to hear of your misfortune
i live in minnesota,i believe your climte and mine are pretty much the same
its winter here now,our humidity is usually between the 25-35% area at this time of year
i am currently working on a hick and a hhb bow,i do my work in my basement.
the humidty down stairs is a constant 35% this time of year(i keep my dehumidifier set at that ;) )
i have yet to have one break for other than bad tillering on my part/pushing it to far to fast
but i have heard of others having issues when the humidity drops this far
jm2cw
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If that is the case, I would never build a bow, our humidity averages around 23% most of the summer, and it isn't unusual to see 6%. It usually takes a lot more than that to cause problems, especially for hickory. Hickory does well down to about 5-6% moisture content where most others would break.
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I thought hickory strives on low humidity.
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Than I really have no idea what happened; the tiller looked good and had not caused any problem so far, the bow was exercised well, the bow was not really stressed at that draw weight and pull considering it was 69" NTN.
Who knows...
Thanks for your replies!
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Does sound like your bows were too dry. Was that 35% R/H where the bows were kept? Do you have a temp/humidity monitor? Once you start monitoring these conditions you will notice that well tillered bows magically quit breaking......Art
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Yep, I read Justin's reply. And I understand that 23% R/H =about 5% MC and 6% R/H = about 1 1/2% MC in wood. My hat's off to him for building anything in those conditions. Perhaps he has some tips he could share with us..........Art
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Soak it in Buffalo urine and salt water to bring the moisture up a little.
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Yep, I read Justin's reply. And I understand that 23% R/H =about 5% MC and 6% R/H = about 1 1/2% MC in wood. My hat's off to him for building anything in those conditions. Perhaps he has some tips he could share with us..........Art
I don't have any pointers myself but I've been keeping my wood in my house until I build bows from it and My house is single digit RH year round....Got me.....
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Yep, I read Justin's reply. And I understand that 23% R/H =about 5% MC and 6% R/H = about 1 1/2% MC in wood. My hat's off to him for building anything in those conditions. Perhaps he has some tips he could share with us..........Art
I don't have any pointers myself but I've been keeping my wood in my house until I build bows from it and My house is single digit RH year round....Got me.....
My biggest tip is don't get attached until it is finished.
I keep a lot of my wood in the house also. Osage, Ipe and Hickory are fine if kept out of direct sunlight. If you store them very long in direct sunlight they will dry to much and explode. Stay away from Yew when it is super dry, it is not forgiving at all.
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Now that's some prime info Eddie ;D
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I don't think that's likely. That's the way it goes. Jawge
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The only time I have seen hickory break clean across the back is when fungi had set it. I have seen it bend almost in half or splinter badly but never a clean break.
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Sorry for your loss Frank. I've often wondered about the same scenarios as we live in a high desert region and often have very low humidity. We also have a wood stove for our main heat. I've never had a problem with it but we have a couple big aquariums in our house and I wonder if that keeps the moister enough in the house.
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I'm with Pat,even tho the wood looked good,I have had Hickory do that,but never had a problem with getting Hickory to dry. Sorry :) It happens. 2 in a row is bad for sure,I once broke 3 in a matter of hours,made me want to quit :) but I didn't. :) :)
Pappy
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Thought about quitting, too :'( :'( :'( ...but...nah... 8) 8) 8)
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It had nothing to do with moisture. The wood was bad. Was it from a board? The only way hickory is going to break like that is if the wood is bad, like from a fungus as stated by PatB. So take comfort in knowing it wasn't your fault. The wood just let you down.
CP
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I got so used to breaking them that it doesn't phase me. Pick up another stave. These days I don't blame the wood. I blame myself. Jawge
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" Humidity's been down to 35% for a few days now".
"flawless pieces of wood"
"no splinter had lifted, no glueline had failed"
"felt a sudden stacking "
That last one was a certainly a clue! Man said it was a flawless piece of wood, got to take his word on that! Heck, his inside humidity could have been down to 0% for all we know. No mention of a temp/humidity monitor.
Where you guys getting BAD WOOD? Art
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The wood around here gets to be 6% pretty quickly in the winter. So what if it is the low humidity unlikely but what if it is? What are you going to do? On completed bows no finish is a complete and total moisture barrier. The wood will reach equilibrium with its environment eventually. There are not many places on earth where bow building is impossible because of low humidity. Jawge
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I have a humidifier running none stop this time of year George. And I can barely get the R/H up the 41-42%. That's slightly less than 8% MC in my bows so I mainly stick with using hickories and Osage bows this time of year. Merry Christmas George! Art
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just move to oklahoma we got more than we can stand. sorry for the luck, it will get better.
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That reminds me, Art. Got get mine out of the attic. Merry Christmas! Jawge
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I got a moisture meter from Pat a few years back because i was worried about low RH. My garage is not climate controlled but it seems that most woods stabilizes at around 9-10% and stays, hickory around 5-6%.
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Whatever the reason for the failure was, low MC had to do with it I'm sure.
Dry weather, fire in the oven most of the time I'm home in the 200 years old house I live in... First thing to do will be installing moisture meters to get a better idea of the scenery.
Bow building for now will be roughing out staves and GLUE UPS (should be the best time to do that...)
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" Humidity's been down to 35% for a few days now".
"flawless pieces of wood"
"no splinter had lifted, no glueline had failed"
"felt a sudden stacking "
That last one was a certainly a clue! Man said it was a flawless piece of wood, got to take his word on that! Heck, his inside humidity could have been down to 0% for all we know. No mention of a temp/humidity monitor.
Where you guys getting BAD WOOD? Art
Because a "flawless" piece of hickory doesn't just go "bang". Like PatB said, it would lift a splinter first and you would hear a tick way before you heard it completely let go. A piece of hickory can appear flawless to the eyes but if you don't know to recognize it could be bad wood due to a hidden rot or fungus and consequently go "bang".
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Cacatch, where do you? Are these board or log staves? Jawge
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Jawge, do you mean where do I live? If so, I'm in Indiana.
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Oh sorry. Yes, that's what I meant. I think the climate there is similar to ours. If what you mention is a continuing problem I guess you will have to do what Art does. But I am still skeptical. Jawge
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I'm not sure what problem you are referring to, Jawge. I think maybe you are confusing me with what someone else wrote? I just said that my take on it was his hickory wasn't good and that it was the wood that let him down, not what he did with it in this case. :)
CP
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LOL. I must be tired. Sorry. Jawge
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No problem, Jawge - I know the feeling! ;)