Author Topic: restoring a bow left strung leaning against a fence for a year  (Read 4423 times)

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Offline willie

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Re: restoring a bow left strung leaning against a fence for a year
« Reply #15 on: July 22, 2019, 01:58:13 pm »

 It seems rather unlikely, but if anyone has actually successfully reversed set in a finished bow please do post the suggestion.

Dave
I have... and I did... it was the first answer you received ::)
Ok, it was Hickory not Ipe.
https://bowyersdiary.blogspot.com/2013/03/big-bow-detail-and-hickory-challenge.html
https://bowyersdiary.blogspot.com/2013/03/hickory-challenge-result.html

I even allowed you an added safety margin by suggesting backing it...
In your original post, you didn't mention it was of sentimental value.
There are two real options... if you don't want want to take any risk... clean it and hang it on the wall.
On the other hand if you want to be able to shoot it, it's a no lose experiment, 'cos you've got to do something.
Del
PS. If you ask me a 3rd time.... the answer will still be the same  ::) :o ;D >:D

I looked at the posts on Del's blog to try to determine if the set in the hickory bow was caused from being over drawn or left strung for an extended period. Perhaps Del never had a chance to find out what caused the set that he repaired.
(nice job on that bow BTW, Del). :)

For the sake of discussion, lets assume over drawing creates 'set', and an extended stringing causes 'creep', both similar in appearance. But are they the same? We commonly assume set is the result of compression damaged cells, but creep may be the rearrangement of cells in relation to each other. Certainly heat can firm up cells that are not dried to their full extent, but we also like to presume that heat allows us to rearrange cells when we use it to straighten or bend.
Could this be more similar to the long term damage that Dave has experienced?




Offline Woodbear

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Re: restoring a bow left strung leaning against a fence for a year
« Reply #16 on: July 22, 2019, 10:31:25 pm »
Ahh, ….. how did it get left in the field. … Twas a friend who I let use the bow who forgot where he left it, and forgot to let me know it was missing. I discovered the “missing” part the next week, only just now found the bow about a year later while walking the fence line.
 
So…… there is good news and bad news. The good news is that it is no longer missing and remarkably little weather damage, considering a year in the rain and sun. The bad news is massive set. ....... Being able to restore the bow will significantly help my mental attitude to be gracious about the incident.

Regarding set from over draw, vs creep from long brace time (not to mention hot-cold rain & dry), I am not sure there is much difference. Hypothetically, set from overdraw is thought to occur when the strain on the belly exceeds the elastic limit and the portion that exceeds the limit is permanently compressed. However, the matter of exceeding the elastic limit must also be time dependent, because after a year, the shape is permanently changed in spite of not reaching the strain of either full draw or over draw.

Del,
Thanks for saving me asking a third time, I have your answer……Nice restoration on your long bow. It is good to know it can be done with hickory. The feedback on heat with Ipe is negative, so I am considering backing while held in mild reflex. Not sure how thick a backing & how much “reflex” it would take to pull it straight again. I don’t have any Ipe I want to sacrifice for backing. I have a hickory board 1” thick "flat sawn" with grain feathering out on the face about every 8-12 inches. How good does the grain on hickory have to be to back Ipe?

Dave

bownarra

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Re: restoring a bow left strung leaning against a fence for a year
« Reply #17 on: July 22, 2019, 11:08:31 pm »
You'll likely get other answers but - pretty good would be my answer. I've had backing fail on narrow, strained bows. Somebody on here is bound to have some decent hickory for you.

Offline Del the cat

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    • Derek Hutchison Native Wood Self Bows
Re: restoring a bow left strung leaning against a fence for a year
« Reply #18 on: July 23, 2019, 12:48:14 am »
I wouldn't risk pulling any reflex, or maybe just 1/4" - 1/2" max. Gluing on the backing should pull it straight.
If you must pull it into reflex, I'd have thought steam wouldn't do any harm and may help...?
Problem with getting greedy is...
https://bowyersdiary.blogspot.com/2019/04/tired-old-warbow-experiment.html
It took out the set, stiffened it up wonderfully... until :-
https://bowyersdiary.blogspot.com/2019/04/tired-warbow-result-etc.html
Del ;D ::)
« Last Edit: July 23, 2019, 01:13:29 am by Del the cat »
Health warning, these posts may contain traces of nut.

Offline Eric Krewson

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Re: restoring a bow left strung leaning against a fence for a year
« Reply #19 on: July 23, 2019, 05:36:15 am »
I have repaired a lot of bows, some with monster set but never worked with ipe but have fixed a hickory bow that was never unstrung and had 8" of set. Reflexing on a caul and heavy toasting of the belly cured it. Because of my lack of experience with ipe I will have to watch and learn and see how this goes.