Author Topic: Propeller tip help request  (Read 2810 times)

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Offline Digital Caveman

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Re: Propeller tip help request
« Reply #15 on: August 27, 2020, 03:30:52 pm »
I thought damp wood chrysaled more, not being as hard as very dry wood. 

Personally, I would be quite concerned if chrysaling happened before the bow was even shot, but I don't use sinew.
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Offline Mesophilic

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Re: Propeller tip help request
« Reply #16 on: August 27, 2020, 04:19:50 pm »
I'm don't know about damp vs dry wood when it comes to chrysals.  But wood in general here is so dry it just cracks, splinters, and checks just by thinking about putting stress on it.  So nothing surprises me anymore.
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Offline Pat B

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Re: Propeller tip help request
« Reply #17 on: August 27, 2020, 04:31:49 pm »
What's the RH in your house? Wood and sinew/hide glue will find moisture equilibrium with it environment. So at 50% RH there will be a M/C value for the wood at a specific temp.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Mesophilic

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Re: Propeller tip help request
« Reply #18 on: August 27, 2020, 07:04:05 pm »
Sorry, I don't have anything to measure RH in the house, just my mositure meter for objects.

But if this gives you any idea how dry we get, the weather currently says it's 24% RH outaide right now, but that's with a 60% chance of rain.

Around noon, with low chance of rain, it's generally single digits with temps in the upper 80's to mid 90's.
Trying is the first step to failure
-Homer Simpson-

Offline Pat B

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Re: Propeller tip help request
« Reply #19 on: August 27, 2020, 08:28:53 pm »
You might have to store your bows near the swamp cooler.  ;D
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline bradsmith2010

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Re: Propeller tip help request
« Reply #20 on: August 28, 2020, 04:35:25 pm »
please show us the checks
sinew bow usually fair will in dry climate,,
maybe the bow was over stressed before the sinew was appied??
I did blow up a bow a few days ago,, and am sure RH was a factor ,, but other factors were
over stressing the design
too thin on the sinew layer,,
really just not enough wood for the weight I was pulling, or the draw length,,

but the bow did not have any chrysals,, and I have not had a problem with that,
I did have a friend that chrysaled his bow ,,when first bracing and had a weak spot,,that caused the problem,,
it is really dry here in Santa Fe, New Mexico,,
I guess my point is, other factors may be an issue as well as the RH,, you should be able to get a good stable sinew bow,,

Offline Mesophilic

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Re: Propeller tip help request
« Reply #21 on: August 29, 2020, 01:59:57 pm »
Sorry, I've already destroyed it to reclaim the sinew, and didn't bother taking any pictures.

What cued me in, was finding what looked linitially ike scratches that wouldn't sand out.   

In reflection,  I'm pretty sure this is entirely my fault, just don't have enough experience and about to throw in the towel anyway.   The learning curve is too steep when you don't have access to bow woods.  This is probably the last $100+ bill I'm adding to the wood pile.  Could've bought a real nice bow from a reputable maker for all the $100 bills I've burned up in the wood stove the last few years.

Anyway when the sinew dried and I started working on the long string, the inner limbs were bending too much and the outer limbs not enough.  I think working it on the pulleys to check the limbs put too much stress there.   I personally feel that the lack wood mositure content contributes to a very unforgiving situation based on the wetter climates I've lived in.  Didn't have one tenth of the problems I have compared to when I lived in Ohio.

Trying is the first step to failure
-Homer Simpson-