Primitive Archer

Main Discussion Area => Bows => Topic started by: StickMark on July 15, 2021, 10:07:20 am

Title: D97 stretching in heat?
Post by: StickMark on July 15, 2021, 10:07:20 am
Topic says it all.
Am I not making the timber hitch tight enough, or is my D97 string losing brace height in 95-105 degrees?
Losing about an inch?
Also, if you want to compare D97 to B55, my old standby, please do.
(might be hunting this summer with a rawhide and/or sinew string regardless)

THX
Title: Re: D97 stretching in heat?
Post by: Pat B on July 15, 2021, 10:20:37 am
Mark, some of the no stretch strings have a hard time holding a bowyers knot from what I've seen. I only use B-50 or B-55 and I don't have that problem.   Are you pre-stretching your strings after you make them?
Title: Re: D97 stretching in heat?
Post by: StickMark on July 15, 2021, 10:37:27 am
Pat,

I place the string on a hook in the garage, and pull hard on it, then hang about 30 pounds on it a while.
This string has 200-300 arrows down range already.
My suspicion is that the knot is slipping, like you say.
I have a twist or less per inch in the string.

I may have to make it initially with a higher brace height, an inch or more, then shoot it in, instead of chasing the perfect height right off the bat. OR, trade it, as the B55 did not slip / stretch.
Title: Re: D97 stretching in heat?
Post by: Pat B on July 15, 2021, 10:44:06 am
Try an extra tuck or 2 in the bowyers knot to see if that helps hold it more securely.
Title: Re: D97 stretching in heat?
Post by: Selfbowman on July 15, 2021, 12:55:29 pm
Wax also stretches as it is tightened . Usually muchof a problem .
Title: Re: D97 stretching in heat?
Post by: Pat B on July 15, 2021, 01:10:18 pm
Also, once you get your stretched string the length you want you and tie a stop knot to prevent the bowyers knot from slipping. I do this on my bow strings.
Title: Re: D97 stretching in heat?
Post by: airkah on July 15, 2021, 03:01:46 pm
I think what you and Pat suspect of the string slipping is probably right. I've never noticed excessive stretch from d97 living in FL with flemish twist strings.
Title: Re: D97 stretching in heat?
Post by: bownarra on July 15, 2021, 03:05:11 pm
Simple answer to this one :)
Simply add 4 strands of B55 to the reverse twisted section that you tie your knot in.
Also make certain that the first 'wrap you do is very tightly snugged up around the standing end, not lose open wraps.
Putting the B55 in there means you don't have to be so critical on the bowyers knot.
As a side note dyneema has a very low mellting point.
Title: Re: D97 stretching in heat?
Post by: organic_archer on July 17, 2021, 09:51:58 am
It’s just slipping. As others have said - hard to get a bowyer’s knot to hold with FF. It’ll hold if you wrap it around the string twice before finishing the bowyer’s knot.  (SH)
Title: Re: D97 stretching in heat?
Post by: StickMark on July 18, 2021, 02:25:45 pm
Thx for the replies.
Just returned home, and will try all these ideas.
(maybe the old B55 worked just fine...)
Title: Re: D97 stretching in heat?
Post by: SLIMBOB on July 18, 2021, 03:13:45 pm
http://www.primitivearcher.com/smf/index.php?action=dlattach;topic=49876.0;attach=107729;image

The link should take you to a post. If the knot is slipping, this helps.
Title: Re: D97 stretching in heat?
Post by: bassman211 on July 19, 2021, 08:40:57 pm
No rule that says you can't put a couple more twists in the timber hitch.
Title: Re: D97 stretching in heat?
Post by: StickMark on July 20, 2021, 10:46:28 pm
after seeing the link SLIMBOB sent, I put in another twist after the initial one, then across the loop, and wrapping upward....problem seems solved.

Will check it again, after shooting more arrows.