Primitive Archer
Main Discussion Area => Bows => Topic started by: Muskyman on March 15, 2024, 03:00:11 pm
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So I was thinking about flipping the tips on this bow and when I was getting ready to do it I noticed this in the limb. I’m assuming it’s a stress crack. It’s in the belly side about a foot from the tip.
It’s was going to be a trade bow but probably not any more.
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Belly side?
Does the crack raise a splinter? can you rub a cotton ball over it without catching fibers?
Did you attempt any recurving in this area?
In the pics it looks more like a tension failure than a fret which would be typical for the belly side.
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It looks like the type of crack you can get from bending with dry heat. When you bend wood too far and it's not hot enough this can happen.
I know you haven't flipped the tips yet, but did you induce a reflex, or straighten a kink?
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I did reflex it with dry heat Hamish but any other straightening was done with steam.
It’s not been recurved Willie and yes it’s on the belly side. I can rub a cotton ball over it without catching anything.
I can rub a fingernail over it and feel nothing, it never raised any splinter on it.
I’d never noticed it before. I had taken off 3/4 inch on each end and was going to flip the tips. Had it in my caul and was putting oil on it and saw it. Stopped right there and brought it back inside the house never did heat it any today, just when I reflexed it.
If I can save it that would be great. I’ll just put the overlays on it and call it a day. Still not sure I’d want to send it out in a bow trade unless it’s for sure not an issue.
Weather I keep it or send it out in the bow trade I’m guessing soak it with thin super glue?
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looks can be decieving especially in pics.. if this is the straight limbed bow shown in http://www.primitivearcher.com/smf/index.php/topic,72579.msg1019712.html#msg1019712
can you indicate in this pic with an arrow where exactly the defect occured along the limb?
there also appears to be a red streak extending upward from the crack near the edge of the limb in the pic above. is there something happening between the grain there?
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Would you show a pic of where on the limb it is. Looks to me like a grain lifting which is unusual on the belly but if you reflexed the limb with heat that might be why it happened. If there is enough thickness on that part of the limb you could saturate the lifted area with thin super glue and clamp it shut. Then scrape it down a bit. Just be sure you don't glue the clamp to the bow. ;D You could add a wrap over it for insurance.
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Oh boy, that is a bummer. Hope you can save it. I hope to work on my trade bow tomorrow...
Paul
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Willie I think the red streak is where I got a little carried away with the scrapper to be honest. I think it’s a little thinner there. And yes it’s the same bow. I’ll post a picture but not sure if it was the same limb I marked in red same area but could be the other limb.
Pat it’s not really lifted at the spot. I rubbed a cotton ball across it and it doesn’t grab it at all. If that’s what you’re asking basically. When I saw it I actually tried to bend backwards to see if it would move and I couldn’t see anything but I didn’t really move it much if at all.
Obviously it’s lifted but at the very least it has been sanded smooth. It must have happened when I reflexed it. I just don’t understand why I hadn’t seen it before I’ve worked on this bow a lot since I reflexed it. I’ll post some more photos
First one is a closeup with my phone
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+1 for Pats advice with superglue.
I don't think it's going to break anytime soon, unless you try and recurve it. That being said I personally wouldn't be happy giving it away or selling it, and it would probably be relegated to the naughty bow corner. (I would still shoot it myself though).
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either side in the pic, your limb is not bending excessively, so I doubt it is a compression fracture or fret on the belly as one would expect there.
wood sometimes has natural defects or rather stave damage, not apparent before you apply a finish
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Feeling the same way Hamish. To be honest my first thought was just that. After being disappointed that is. I might end up trying to take it down past the bad area and see if it has a light weight bow in it. I’ve got a couple other staves for backup. Also one I’ve been working on..
I’m kinda bummed about it but, I’ll be better when I get the next one made.
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Don't worry Musky. I know someone, who might have done the exact same thing before. My ur I mean his next bow was turned out just fine.
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Willie I think the red streak is where I got a little carried away with the scrapper to be honest. I think it’s a little thinner there. And yes it’s the same bow. I’ll post a picture but not sure if it was the same limb I marked in red same area but could be the other limb.
Pat it’s not really lifted at the spot. I rubbed a cotton ball across it and it doesn’t grab it at all. If that’s what you’re asking basically. When I saw it I actually tried to bend backwards to see if it would move and I couldn’t see anything but I didn’t really move it much if at all.
Obviously it’s lifted but at the very least it has been sanded smooth. It must have happened when I reflexed it. I just don’t understand why I hadn’t seen it before I’ve worked on this bow a lot since I reflexed it. I’ll post some more photos
First one is a closeup with my phone
Ya mike it’s a bummer when this happens. Like what’s was already said it likley happened during heat induced reflex. You probably didn’t notice it at the time as it was filled with wood dust. I suspect that it’s one ring or two that has separated when backset induced. I still think you may be able to put slight flipped tips if you take measures to clamp this area of separation and keep it further up then the bad spot. I might try and take it down to next good solid ring on belly there and match both ends and then add your flipped tips or recurves to maintain your desired weight. It looks to me from the pic that your inner fade out area on right limb looks little stiff in comparison. Could just be the pic but seems that way. Best of luck with it. There could still be a bow in there!
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Dave, it’s possible it’s a bit stiff in the fade. Also there was a knot in the handle area and the limbs are not quite parallel to each other from one side of the handle to the other, if that makes sense.
At this point I may try and remove the problem area and see what happens.
Thanks for the responses and help and suggestions from everyone. I’ll post what happens with this bow and maybe try and document the process and end result for people like me who are still learning.
I have one final question I would like answered. I read somewhere, maybe on here, not sure.
Anyway, I read you don’t want to use steam for bending after you have used dry heat on a bow for bending. If I’m remembering correctly it said you could use dry heat after steaming but not steam after dry heat.. agree or disagree?
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I've never heard about the steam/dry heat thing but I mostly use dry heat.
The tips look stiff so you could probably take some of the belly down on both limbs. I'd super glue the crack first, let it cure out completely then scrape the tip down a little.
Generally the belly side is more acceptable of maladies like this. The back is more critical and a clean back is critical for a durable bow. Not so much the belly except for frets.
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To late Pat 😁. I figured what the heck. I’ll post some pictures in a bit. Basically I took it out to the shop and started working on it with a scraper and a sander and in a few minutes it was gone. I put oil on it to try and highlight it and it’s gone.. haven’t had it on the tree yet to see what the tiller is doing but that’s coming. I’m going to try and flip the tips and hopefully gain a little draw weight and try and match the other limb up with the one with the issue and see what happens.
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Okay, time for show and tell. I’ll post pictures
I started scraping and sanding slowly and could see it going away. I didn’t take a lot off before it seemed to be gone. Once it was gone gone to the naked eye I put some oil on it and couldn’t see any sign of it. Put it on my tree with a long string and pulled it to about brace height.
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Here it is with one limb flipped
I’ll give it a few hours and then do the other limb
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Limb number 2
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Good save. Looks like it was pretty shallow. I think you can still get something in your weight with this one.
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The steam before using dry heat is real. Once wood has been brought down to really low MC by artificial means its propensity to be bent by steam is greatly reduced. Thats why chairmakers, and other craftsmen that need tight radius, steam bent curves always use air dried wood, as kiln dried wood is nowhere near as elastic. Every book on steam bending or wood usage I have read says the same message.
Whether this is due to having lower MC, or if its due to permanent structural change, I don't know.
If its just due to MC, then rehydrating the wood by soaking for a couple of days might be an option.
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Nice result Musky :OK
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Thanks guys, I have no idea what the draw weight will be but I’ve got it bent on both limbs and didn’t see anything that jumps out at me. I’m going to have to straighten the tips some to get them lined up good but it came through the day better than it started..
It has approximately 4&1/2 inches of reflex now and measuring from tip to tip in a straight line is 66 inches. Left it out in my shop for the night to let it rehydrate. Might try and put tip overlays on tomorrow. Should I let it rest for another day to rehydrate or will I be ok to bend it tomorrow?
Here’s a pic or 2 of it now..
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I'm very conservative, and wouldn't rush going to string it, or shoot it. Wait a week and come back to it, give it time to properly rehydrate it. Hey it will probably be alright, but why risk it being too low in MC, and possibly snapping, osage aint the same as hickory.
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Whether this is due to having lower MC, or if its due to permanent structural change, I don't know.
if you think of the cellulose cells as reinforcement and the lignins as the supporting matrix,
I think once the lignins are baked, they dont easily want to soften again
muskyman, at least wet the back with wet rags overnight
do you have a gram scale you can weigh the bow before and after?
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I’ll wait a few days at least no need to panic now. I’m already working on a backup. It was a belly split from the bow I’ve been working on. It’s a little narrow. Only 1.33 inches wide after taking it down to bow shape. It’s at floor tiller right now.
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Whether this is due to having lower MC, or if its due to permanent structural change, I don't know.
if you think of the cellulose cells as reinforcement and the lignins as the supporting matrix,
I think once the lignins are baked, they dont easily want to soften again
muskyman, at least wet the back with wet rags overnight
do you have a gram scale you can weigh the bow before and after?
Ya Willie is bang on here. I’ve noticed this too. The lignins and pectins in the wood actually harden with heat. This is particularly true of heat treatment on white woods when a deep heat is applied to permanently change the cellular structure of the wood. I’ve tested this out myself to see if tips could be heated in after with steam which all failed. Even on the ones where less heat treatment extended out towards the tips. Belly cracks always appeared. I would suggest the similar problems arising with non white woods with heat corrections especially dry heat. This being said I’ve seen some success with more then one steam only corrections fyi. This is because you do t heat past a point of no return. Dry heat can often go past the point of “no return”. If that makes sense.
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As I said before, not sure where I read about the not steam heating after dry heating but I do recall reading it. I believe it was on this site. I don’t recall getting any bad info from here.
And yes Willie I do have a scale. Haven’t weighed this bow for a while. Mainly because I’ve been constantly working on it. I think I’ll weigh it today and see if it gains any weight from rehydration over the next few days. I heat with wood in the area I keep my bows so I’ve been keeping it outside in my shop.
I did try and line the tips up today but am going to let it sit for a while now..
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Went from 684 grams to 686 grams overnight. I’ll weigh it again tomorrow..