Primitive Archer
Main Discussion Area => Bows => Topic started by: Kidder on June 19, 2021, 04:20:56 pm
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So I’m just finishing an BBO. It’s a relatively low stress design - 66 TTT, 1 inch Perry reflex post shooting in. And I’ve got a pretty short draw - 25 inches or so. It has a tiny pin knot on the side the runs to the back under the boo. Upon putting a couple coats of finish on it I’ve noticed there is a small fret right above the knot. It’s located on the bottom limb about 3 inches above the middle boo node. Everything else looks fine. Is this something to try to fix or just leave it?
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The tiller looks very good. You could put a wrap over the pin and one on the opposite limb for symmetry. If nothing else might give you a little security. A drop of super glue in the check too.
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I had a similar issue on the plains bow, and I thought about a sinew wrap, but figured that would be hiding something and so decided to adjust the tiller, and now it is too light. :-\
Yours will probably be fine though, I have one bow that fretted by a grain wrinkle, but it never got worse. I think frets due to bad tiller are much more serious.
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drop of superglue and take a photo or some measurements to monitor it
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I doubt superglue will do much for it. It can't fix what's already crushed and can't get into the wood that isn't crushed yet. That and the wrap thing are just 'feel good fixes', imo. I'd shoot it and see what happened. If it got any worse and I really wanted to try to save it, I'd do a half round patch like Dean Torges advocated. I've had good success with them.
http://www.bowyersedge.com/patch.html
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A half round patch won't hold up in the long run, I tried several of them, they always turned loose, it might be a months or several years but they do turn loose.
I would ignore the small fret, the bamboo will hold your bow together. I would remove the finish and superglue it, marvelous stuff.
This patch lasted three years, I replaced it and it only lasted a few weeks.
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Thanks for all the replies. I’m just going to CA it and call it good. Bows could stop breaking my heart anytime now...
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Superglue won't do anything. Patches are very difficult to get right(your patch is too small Eric, the problem is the mating edges are at too sharp an angle). Wrapping the limb does nothing.
The problem is the pin knot. Nature put it there and that's it. Not much you can do now.
To avoid issues like this you must use super clean belly wood. Learning how to judge belly wood that has 'issues' is a real fine skill. Personally now I only use the very best materials on lam bows, after seeing pin knots fail too many times.
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The English approach to fret repair seems more effective than the Torges "scoop" patch. They use a much longer piece, and rasp out the fret, with a much more gentle transition, more surface area for the glue, so the ends are much less likely to lift. Still have to use top glue like urac etc. Del probably has a video tutorial or blog for it. Chime in please Del?
No surprise,the best cure for a pin knot is always to compensate for it, from the layout, through to tillering.
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Osage is tough stuff. Backed with bamboo, your fine tiller and a conservative design like you have there - I say shoot it a couple thousand times and see what happens. I wouldn’t worry over that spot unless it causes a problem at some point.
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Bownarra, have you read Dean Torges's writings or just offering an opinion? He recommended making the patch a little undersized and leaving an excess amount of glue in under the patch, I followed his directions to a T.
Tell me about all the similar patches you have tried and what the outcome was.
Like I said before, If I haven't done it I don't say a word when a question comes up. I think the guys who ask a question deserve an answer from someone with actual experience, not opinions.
I have to agree with the tillering on that bow, spot on. As for superglue, you are right if the crack is microscopic, the glue won't wick in. One property of super glue is soaks in the surrounding area a hardens it, like case hardening making it less likely the crack will spread.
For maximum wicking I used to keep a bottle of the thinnest Zap-A-Gap superglue on hand, it is thinner than water and soaks right in.
The last time I posted that property on a muzzle loader form about crack fixing I got the horse laugh from the so called experts like we see here sometimes.
One of my critics went so far as to call the company that made a particular brand of super glue and ask a tech rep about what I had posted. Surprise, surprise, the tech rep told him "yes, that is a property of our glue that we have never emphasized".
I didn't read about this superglue property, I found it out from fixing cracks in bows and flintlock rifle stocks.
If any of you have used superglue and sawdust as a filler/patch you will see the chemical reaction between the two, lots of heat and even smoke, the superglue is changing the composition of the wood.
Here is an example, not bow related but it is wood; I bought a M/L kit (Kibler SMR) at a bargain price, when I got the kit I found the previous owner had neglected to mention there was 2 1/2"crack in the forestock. Apparently he didn't know how to remove the barrel and had yanked it out cracking the stock.
The wood was very thin at the crack, I superglued the crack and held it closed with my fingers until the glue set, I knew this probably wouldn't hold so I went inside the barrel channel and soaked all the wood in a 1 1/2" circle around the crack with as much superglue as the wood would suck up. After the glue set the wood was so hard a chisel wouldn't cut it. This crack will never turn loose.
The crack is above the pin angled down to the left, fixed properly it is hard to see.
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I have looked at the pic of your bow since you first posted it looking for the fret. I have never had one on an Osage bow, pins or no pins, though I have had them on white woods. Granted, yours is a lam bow and that changes things I suppose. None-the-less, I have noticed in blowing up the pic and scrutinizing it, that the bow appears to get marginally more narrow at that spot. It could be just an optical illusion in the pic. Have you checked it with a set of calipers? If I am wrong, just disregard, but if it is more narrow right there it could influence which way you should go with it.
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Another thing; After I posted the above crack fix one of the "experts" decided I needed a scolding for using superglue to fix a crack. He said superglue would oxidize in a wood repair, turn white and turn loose after 5 or more years.
I don't know what planet he comes from, these guys never miss an opportunity to give someone like me a scolding for the error in my ways.
Turns white and oxidizes, horse hockey;
Here is one of my early bows, one of those "I will make a bow out of this tortured stave just to see if I can" bows. It has 13 superglue filled drying checks down the back, plenty of shooting and none of the cracks ever oxidized or turned loose. Now that the bow has turned dark you can't even see them. I made the bow in the 90s but reworked it in 2002 to have my typical narrow tips and gave it a gizmo tillering. Turns out this wood is one of the top pieces I ever made a bow out of, the cast is incredible and it never took any string follow at all. I made it before I started reflexed bows with heat during the tillering process.
Being an old dude, I only shoot 45@25 now so this bow is relegated to the "wall art" category.
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Oxidize and turn white? Huh? Cured cyanoacrylic is chemically inert, it takes a pretty serious agent to even get it to debond and even then requires lots of surface contact along with time. If you wanted to undo that crack in the rifle stock you would need to submerge it in acetone for weeks and weeks! Some poor ML guys are just desperate to be known as "hysterically correct" and cannot help but run their mouths on 21st century media about how they are 18th-century transplants! LOL
The super-thin stuff is designed to wick into tiny spaces, and what is wood? Nothing but a pile of lignin absolutely full of tiny spaces! I'd also recommend using the thin stuff to soak into the cracks. Zap-A-Gap has been around a very long time and is a high quality product.
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My patches are holding up fine, Eric. I don't advocate something unless I've done it myself either. Sorry, but you didn't follow Dean's instructions to a T, I can tell just by looking at your patch. Also, he didn't recommend leaving the patch undersized, or with an excess of glue under the patch. Dean would correct you himself if he were here. Revisit the article, then we can discuss further if you like.
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I got my info from back when Dean posted on the Stickbow site a good bit before the keyboard warriors drove him off. Pretty sure his initial post on his website said the same thing, this would have been about 20 years ago. I concede that my info is incorrect and not up to date, thanks for the heads up, it could help a lot of people.
I did this type of repair about 15 years ago, I had such poor luck with it I only tried it one more time several years ago, that one failed as well but I was trying to patch a place on a friends bamboo backed ELB that encompassed way to much of the limb and I didn't expect it to work but had to give it a try.
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For sure each bow brings it's own set of circumstances and chances of successful fixin, or not. All we can do is try to raise the odds. It won't work on all of them.
Here's one I did in 2011. This is it today thousands of shots later. It's a 62# bamboo backed recurve.
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Now that looks really well done.
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Osage can handle a pile of pin knots on it's limbs.Here's an old 60" TTT slightly bendish handled bow but still 3/4" thick at the handle I made years ago with thousands of shots through it.A total of 18 pin knots on the belly not counting under the handle wrap.Around 1 and 3/8" wide.Pulls 65 #'s @ 28".
Back...slightly rounded
(https://i.imgur.com/zX8qNiH.jpg)
Belly...slightly rounded
(https://i.imgur.com/GzO5hyI.jpg)
Side view
(https://i.imgur.com/va6Tbbu.jpg)
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Dws that repair job looks very precise. Nicely done.
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Here's Deans article. http://www.bowyersedge.com/patch.html It's easy to see how the process can be misunderstood when it comes to the fit of the joint. Dean had a tortured prose that often seemed to contradict what he was trying to say.
FWIW it didn't seem to be keyboard warriors that drove Dean away, it largely seemed to be ego clashing with Tim and Jim.
Sort of like what we're seeing here.
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I have looked at the pic of your bow since you first posted it looking for the fret. I have never had one on an Osage bow, pins or no pins, though I have had them on white woods. Granted, yours is a lam bow and that changes things I suppose. None-the-less, I have noticed in blowing up the pic and scrutinizing it, that the bow appears to get marginally more narrow at that spot. It could be just an optical illusion in the pic. Have you checked it with a set of calipers? If I am wrong, just disregard, but if it is more narrow right there it could influence which way you should go with it.
Slimbob - it’s not actually any narrower width there but the boo is very slightly narrower there and then combined with the angle to show the edge it looks that way. I probably did contribute to it though by making the Osage thinner there trying to work on limb twist, but it isn’t actually narrower.
Thanks for the input guys - hopefully no one gets hit with any popcorn! (-P
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That is a lot of pins, I have never had a problem with them even pins right on the edge I of a limb edge, all bows for the most part have pins on one edge or another.
I just finished this fix of a fix today, I shot the bow cautiously, nothing creaked, popped or tinked so I horsed it back and let an arrow fly, the dang thing shot very well, a little better than before the fix. The picture lighting is a little wonky, the nock looks like it doesn't go across the back but it does.
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Dean posted on the Stickbow that I was an "insult to the true art of bow making", of course I took offence but didn't answer him back. Looking back at the way I did things back then (twenty years ago) he wasn't far off the mark. I was trying all kinds of stuff to see if worked back then, much like I do now but but I didn't have enough experience to see the error in my ways with something ridiculous I was trying.
I do remember Stickbow posters ganging up on Dean and telling him he was an idiot on a regular basis. He was outspoken but he knew his stuff. I ordered a Boyers edge from him and we talked for a long time, he was very pleasant.
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One can learn from mistakes so as not to repeat them. I was taught that knotted areas should not bend as much as the rest of the limb but appear slightly stiffer. I once violated that principle and the bow actually broke.
I know this a lam bow but it is obviously bending too much in that area when the opposite should be true.
Jawge
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One thing I should mention is that I don't like to have a pin knot on the edge of a limb on the corner or where it is faceted or rounded.Especially in the working section of a limb.
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So I lightly sanded off the finish, dumped on some ca and then lightly sanded that smooth before refinishing it. Put another 50 or so arrows through it today. Hopefully in a few years I’ll revisit this post and let everyone know that it’s held up! If not, I might be back sooner! But either way I’ll take the lessons pointed out to heart for the next one.