Primitive Archer

Main Discussion Area => Bows => Topic started by: backtowood B2W on November 26, 2019, 03:08:57 pm

Title: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: backtowood B2W on November 26, 2019, 03:08:57 pm
Hi all  ;D
Finally I will try OO ;D. Have a few but never the nuts to work em down ::).
Most of them have some serious twist like this one - almost 90°!
So i steam bend it to about 10°. This also raised the reflex to about 4" by itself!
Also string alignment with steam in the handle.
I always let it cool out overnight between the sessions. After the handle session I discovered Micro Cracks at the back - spread out in the green marked section. Hope you can see them on the pic.
There I also did most of the untwisting in the first steam session.
The Cracks appeared next day after the handle session where I kept away the heat from that area as good as I could. Guess my guts already knew to take care of this section.

When I take down another ring I will end up with about 8 mm thickness and 39 mm width at that area. Enough meat? OAL 68"
Or can I superglue and ignore them?
I run out of raw hide and a backing is the last what I want on my first osage but probably the safest way...

Thank you for your thoughts!
B2W
Title: Re: Q about OO - MicroCracks
Post by: Eric Krewson on November 26, 2019, 05:06:05 pm
They are real common when you take the twist out of a limb, I superglue them and forget them.
Title: Re: Q about OO - MicroCracks
Post by: Hamish on November 26, 2019, 05:08:39 pm
I can't really see the cracks in the photo, but I'm guessing they run with the grain rather than across the back.

Tricky spot to bend at the best of times, I wouldn't heat anymore, or remove a ring. Just flood the area with superglue, get some more rawhide to back it for safety.
Title: Re: Q about OO - MicroCracks
Post by: bradsmith2010 on November 26, 2019, 05:17:32 pm
It will probably make it without rawhide depending on the design,, depending on how far you draw it etc, etc, etc,,
I think it is worth the investment in time to rawhide back,, but thats just me,, some say it does not do much,, but for me mentally it does,, starting with 4 inches of reflex, the bow is gonna be a little more stressed than normal anyway,, right,,??   whats your target weight and draw,, and width of bow,, ?
  it looks like you have a knot right on the edge of the limb too,,rawhide would help that too
Title: Re: Q about OO - MicroCracks
Post by: bassman on November 26, 2019, 07:52:55 pm
Got sinew?
Title: Re: Q about OO - MicroCracks
Post by: SLIMBOB on November 26, 2019, 09:24:44 pm
Super glue and forget it. Rawhide if you feel compelled but so long as they don’t run off the sides I think your ok.
Title: Re: Q about OO - MicroCracks
Post by: backtowood B2W on November 27, 2019, 01:12:13 am
It will probably make it without rawhide depending on the design,, depending on how far you draw it etc, etc, etc,,
I think it is worth the investment in time to rawhide back,, but thats just me,, some say it does not do much,, but for me mentally it does,, starting with 4 inches of reflex, the bow is gonna be a little more stressed than normal anyway,, right,,??   whats your target weight and draw,, and width of bow,, ?
  it looks like you have a knot right on the edge of the limb too,,rawhide would help that too

I will probably go for a slight Pyramid 45 -50# at 27" draw.
the width is at 1 5/8 right now, ttt 68"
I took a close up from the grain run around the knot too, can still go a bit narrower there.
Title: Re: Q about OO - MicroCracks
Post by: backtowood B2W on November 27, 2019, 01:15:30 am
Got sinew?

Yes I have sinew for two bows, which are already prepped for it, one ash and one juniper. Never made a sinew backing before, so I think better to try on them first before I put my sticky fingers on the king of bowwood :D
Title: Re: Q about OO - MicroCracks
Post by: backtowood B2W on November 27, 2019, 01:21:59 am
I can't really see the cracks in the photo, but I'm guessing they run with the grain rather than across the back.

Tricky spot to bend at the best of times, I wouldn't heat anymore, or remove a ring. Just flood the area with superglue, get some more rawhide to back it for safety.

Tried to take better pics, hope they are visible now. The crack pointed by the arrows runs out about 2 - 2 1/2" outward.

Thanks for your help, I appreciate it a lot - thats what I love in this forum!!
B2W
Title: Re: Q about OO - MicroCracks
Post by: bownarra on November 27, 2019, 02:02:44 am
Those are drying checks caused by the heat.
Let the stave dry some more before making a bow out of it.
Title: Re: Q about OO - MicroCracks
Post by: sleek on November 27, 2019, 02:30:39 am
Pretend they aren't there  and they will do the same.
Title: Re: Q about OO - MicroCracks
Post by: backtowood B2W on November 27, 2019, 04:21:53 am
Hm
Opinions are about 50/50  - superglue and forget/backing - thanks a lot for your input!
Would be great to get some more thoughts for decision.
Problem with backing is, I cannot make corrections with heat anymore. And I'm not sure if I got it straight already.
B2W
Title: Re: Q about OO - MicroCracks
Post by: bjrogg on November 27, 2019, 04:55:04 am
I wouldn't worry about them. Maybe put some thin super glue in them.
Bjrogg
Title: Re: Q about OO - MicroCracks
Post by: mullet on November 27, 2019, 05:50:28 am
I'm with the super glue and leave it group. And I'd let it dry some more and then glue it, too.
Title: Re: Q about OO - MicroCracks
Post by: Eric Krewson on November 27, 2019, 07:33:04 am
I have never backed a bow for its protection from flaws, I have wrapped serious cracks, mostly on bamboo, with thread and superglue and one osage bow with sinew.
Title: Re: Q about OO - MicroCracks
Post by: PaSteve on November 27, 2019, 07:44:36 am
I have less experience than most here. I experienced the same type of micro cracks after taking twist out of an osage bow. I thought I had damaged the bow and it was going to break. After consulting with Pearl he told me to allow the bow to dry out, fill with thin super glue, finish tillering and enjoy my new bow. That's exactly what I did and there have been no issues.
Title: Re: Q about OO - MicroCracks
Post by: bradsmith2010 on November 27, 2019, 10:31:21 am
One thing is rawhide won't hurt anything,,.it can be applied during or after tiller,,.it does protect back from harsh hunting conditions,,your bow could last 100 years with out it,.if u put it on and the bow never breaks,,,you don't know if its helping or not,,.pope and young stated a significant reduction in bow failure after using rawhide on there bows,,.of the bows I made for others,..I can't think of any that failed,..with rawhide
    This bow may not need it,,,just keep the rawhide in mind for future projects (-S
Title: Re: Q about OO - MicroCracks
Post by: backtowood B2W on November 27, 2019, 12:59:45 pm
Thank you guys!
I will try to get it done without backing. As it is my first OO I am somehow curios about its abilitys.
BUT I will also look for good rawhide. Always good to have some around. I like silk and linen backings as well but raw hide just looks more primitive.
Any good sources for rawhide in Europe ? Goat or calv would be great right?
BTW
Title: Re: Q about OO - MicroCracks
Post by: PEARL DRUMS on November 27, 2019, 01:53:58 pm
Those are drying checks caused by the heat.
Let the stave dry some more before making a bow out of it.

Bingo. The stave was too damp and the heat expanded the internal moisture causing it to make cracks and escape. Structurally, you are just fine. But let it sit in 50% RH, or lower, for at least a few weeks.
Title: Re: Q about OO - MicroCracks
Post by: bjrogg on November 27, 2019, 02:35:16 pm
Those are drying checks caused by the heat.
Let the stave dry some more before making a bow out of it.

Bingo. The stave was too damp and the heat expanded the internal moisture causing it to make cracks and escape. Structurally, you are just fine. But let it sit in 50% RH, or lower, for at least a few weeks.

I often give another coat of shellac on the back before steaming.
Bjrogg
Title: Re: Q about OO - MicroCracks
Post by: Eric Krewson on November 27, 2019, 03:52:10 pm
Experience talking here, for me it is the severity of the bend you are straightening rather than the moisture content that causes these micro cracks. All of my wood has been seasoned up to 20 years with none less than ten. If I take the really sevier propeller or a 45 degree dogleg out I will encounter these cracks sometimes but not always, some osage is more flexible than others.

I do think you can get the surface too hot too quickly and get these cracks as well.
Title: Re: Q about OO - MicroCracks
Post by: Hamish on November 27, 2019, 05:18:07 pm
The cracks don't look like they run off the edges, so you can get away without a backing.
 
One thing to remember if you superglue then heat treat/bend it again, the superglue will evaporate.

I sometimes used to get small pressure cracks like that when I bent osage with dry heat. Using spray on cooking oil seemed to solve the problem.
It can happen even with well seasoned wood.
Title: Re: Q about OO - MicroCracks
Post by: backtowood B2W on November 28, 2019, 12:32:31 am
Experience talking here, for me it is the severity of the bend you are straightening rather than the moisture content that causes these micro cracks. All of my wood has been seasoned up to 20 years with none less than ten. If I take the really sevier propeller or a 45 degree dogleg out I will encounter these cracks sometimes but not always, some osage is more flexible than others.

I do think you can get the surface too hot too quickly and get these cracks as well.
This stave has been seasoned longer then 10 years for sure.
I steamed both limbs and the handle and the cracks only appeared where I had the worst propeller twist.
The cracks appeared over night not by steaming it, ok maybe they were there already showing up when the damped surface dried up.
I will definitely protect the back of the other twisted staves I have. Thanks bjrogg for the tip.
Would soaking the bow in water overnight help to avoid this cracks too?
Title: Re: Q about OO - MicroCracks
Post by: bradsmith2010 on November 28, 2019, 09:00:13 pm
I have heard others mention,..different steaming times...effected the checking...
Title: Re: Q about OO - MicroCracks
Post by: Eric Krewson on November 29, 2019, 07:40:24 am
I witnessed similar checks one time that really surprised me. I had a stave leaning against the wall in my garage next to my work bench, we had an abnormally dry day on summer with the humidity at almost nothing.  I looked at my stave and the back was riddled by hairline cracks, dozens of them. I thought "this stave is toast" and put it aside.

A few days later, after the Alabama humidity returned to normal I looked at the stave again and there wasn't a check in the back anywhere. I made a bow from the stave, when I put the finish on I know all the checks would show, none showed, they had opened and closed like they never existed in the first place.   
Title: Re: Q about OO - MicroCracks
Post by: DC on November 29, 2019, 10:15:41 am
I've had them open and close like that when I'm heat treating. They open when it's hot and close up when it cools off.
Title: Re: Q about OO - MicroCracks
Post by: rps3 on November 29, 2019, 08:46:28 pm
Put me in the thin superglue and make a bow category. Never had a problem with checks like that.
Title: Re: Q about OO - MicroCracks
Post by: PEARL DRUMS on December 02, 2019, 08:49:41 am
It makes no difference how long a stave has been cut. It only matters how dry it is and that changes with the RH. A 20 year old stave can be too wet to work if it was stored in 70% humidity for a few months.
Title: Re: Q about OO - MicroCracks
Post by: Weylin on December 02, 2019, 02:35:08 pm
It makes no difference how long a stave has been cut. It only matters how dry it is and that changes with the RH. A 20 year old stave can be too wet to work if it was stored in 70% humidity for a few months.

especially with a freshly chased ring. I like to shellac a chased ring regardless of how seasoned the stave is.
Title: Re: Q about OO - MicroCracks
Post by: SLIMBOB on December 03, 2019, 07:08:55 am
Ive had an Osage belly split check badly the moment I exposed the back ring.  The stave was 5 or 6 years old and the back split had not one check on it.  It had sat as a belly split for a year before I chased a ring.  It checked literally before I could shellac it. 
Title: Re: Q about OO - MicroCracks ---FINISHED---
Post by: backtowood B2W on June 20, 2020, 04:03:43 am
I owe you three bows where I had questions about. I promised to show you the outcome. This is the first:
I flooded the back with superglue to fill the cracks as you recommended.
Thanks again for your help!
I went for an asymmetric pyramid design, as the width at „the around the knot“ - section was very narrow. I started with 14cm reflex. It holds 11,5 reflex resting, after unbracing 1/2“ dynamic set.
Shot a bunch of arrows with it as I finished it in spring, and since its my bow to go for 3D parkour.
Draws smooth and fires an arrow super silent. 0 hand shock.
I´m very pleased and happy with my first osage.
Title: Re: Q about OO - MicroCracks ---FINISHED---
Post by: backtowood B2W on June 20, 2020, 04:05:16 am
64" ntn
42#@27“
Asymetric pyramid
Max w.: 1 1/2“
Nocks w.: 1/4“
Cow horn tip overlay
Mass incl. handle wrap: 490g
Handle wrap: vintage leather, wrapped around and secured with a white cord.
Title: Re: Q about OO - MicroCracks ---FINISHED---
Post by: backtowood B2W on June 20, 2020, 04:06:42 am
10" - 9,5# +5,5#
12  - 15     +4
14  - 19     +3,5
16  - 22,5  +3
18  - 25,5  +3,5
20  - 29     +3,5
22  - 32,5  +4
24  - 36,5  +4
26  - 40,5  +2
27  - 42

I do this with a analog hanging scale, so it is not 100%.
Title: Re: Q about OO - MicroCracks ---FINISHED---
Post by: backtowood B2W on June 20, 2020, 04:08:55 am
hope you like it, let me know what you think!
thanks for watching!
B2W
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: Pat B on June 20, 2020, 06:00:43 am
Very nice OO bow. Beautiful tiller and details.   :OK
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: bentstick54 on June 20, 2020, 07:48:35 am
Super nice bow. Love the character.
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: DC on June 20, 2020, 08:46:12 am
Very nice! I like wiggly bows :D
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: Will B on June 20, 2020, 09:58:32 am
That is a beautiful osage bow!  I love the character and the tapered tip shape and overlays. Excellent work!
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: Hamish on June 20, 2020, 05:04:01 pm
Seriously nice work there. Well worth the extra effort you took getting it just right.
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: backtowood B2W on June 21, 2020, 03:21:21 am
Thank you! appreciate your feedback.
That is a beautiful osage bow!  I love the character and the tapered tip shape and overlays. Excellent work!
The tips aren't really tapered, sorry the photos aren't really clear about that. Cross-section is rectangular except the transmission from limb to fade are hollowed out a little bit. I also start to like the look of this string groove overlays.
Seriously nice work there. Well worth the extra effort you took getting it just right.
not sure what you mean with extra effort, but the hardest part was/is to forget about this cracks. The main bend of this pyramids should occur close to the handle, exactly where the micro cracks are I´m still alerted and check the back after each session. also I chickened to draw it until my desired 28" draw length. But the built of this pyramids isn't that hard, on this one I was lucky to get the string aligned without another correction.
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: Selfbowman on July 02, 2020, 10:24:21 am
Nicely done. Arvin
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: bentstick54 on July 03, 2020, 07:43:37 am
Turned out a super nice bow. Nice work.
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: silent sniper on July 03, 2020, 09:50:33 am
Beautiful work on an awesome bow 👍🏻
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: backtowood B2W on July 04, 2020, 11:38:42 pm
Thank you guys
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: simson on July 05, 2020, 03:02:32 am
Very good work.
The profile pic tells it all!
You should get more osage Martin  8) 8) 8)
Title: Re: Q about OO - MicroCracks ---FINISHED BOW page3---
Post by: simk on July 05, 2020, 07:58:03 am
great bow - fast shooter incl. splendid character.- all them nice details melted to one piece of art!!! when can we hold a handle-wrap class next time? all the best to all of you  (-S