I had to step back and ask for advice before I started ripping up a 98% complete bow. I've been shooting this wrong side shelfed bow for about 40 arrows now, and I noticed what I think is called a "chrysal" on the back of the top limb while applying some linseed oil. It's been shooting but I see that this can lead to failure if left unattended.
I considered 4est's awesome "mole" idea (drilling out the issue with a flat hole, and fill with epoxied dowel) but this issue being on the back of my bow, compared to the belly of 4est's bow, leave's me thinking I can't go the same route. I'm not sure if a plug, then a hemp wrap would work, or don't touch the chrysal, and just wrapping it would work. Really, I have no idea what I can do. So your thoughts would be greatly appreciated.
Here are the pics. It's not pretty.
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_5631.jpg)
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_5632.jpg)
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_5633.jpg)
a chrysal is a compression fracture on the belly side. yours is a crack on the back. looks like it's on a knot and will most likely run to that other knot at the edge. perhaps wrap with rawhide or sinew. it will continue to travel further until it finally breaks. don
Exactly what Don said, chrysals happen on the belly, on the back its a crack.
That crack could be the end of that bow. You could wrap it with rawhide or silk, or you could add a pecan veneer backing over the entire bow.
Thank you for the information fellas. Crack on back, chrysal on belly. Got it.
I'm not ready to give up on this bow. I have lost 4 bows in a row during tillering, and seeing this really kills me.
My thoughts as of now are to drill out the problem, fill with jb weld, and add veneer. Definitely NOT what i'd like to do, but at this point, i'm not sure what options I really have.
I would use super glue and artificial sinew wrapped around the limb a 1/2" above and below the crack. I bet it holds up for a while.
i am not a self bow guy. that is i have yet to work a stave chasing a single growth ring. i am a board bow guy. i believe the reason extra material is left around knots is to prevent what just happened to you. don
I believe that is a board Don? If not it has some serious ring problems. Board bows can be REAL buggers if the wood isnt just right to start with.
I would not feel comfortable with a wrap on that one. Wraps are great for splinters but that is a bit different. If I was determined to save that one, I would have to back it with wood or bamboo. You need something to take over the tension work in that spot. I suppose sinew laid down lengthwise with the limb might patch it also.
I never use any board that has pin knots like that on the back...On the belly they can be ok but on the back they are deal breakers.
That'S a tough one to repair for sure! I hate that for you, looks like a really fine bow too.
No experience with boards, but I encounter pin knots like that a lot in mulberry and osage and I'll glue down a round leather patch over them (most time I'll sinew/skin or rawhide over them anyways). Try to make the patch look like a knot of something. If you can prevent the pin knot from cracking in the first place, they'll usually hold up fine over time. Just thought I'd throw that in encase you start another board bow with pin knots in the back of the board........Art
I would repair that by soaking the fracture with thin c/a glue, maybe even bend the bow a little to open the wound so the glue finds the bottom. then, lay on two courses of silk fabric in c/a glue, extending an inch or so above and below the fracture and down the side of the limb nearest the fracture. then, wrap the ends and middle(directly over the crack) with rod-wrapping thread or similar thread, also soaked in c/a glue. this is a very strong and reliable repair. another nice thing about it is that you can sand it when it's dry, so you can feather out exposed edges. so, it isn't too horrible to look at when it's done if you take care while doing it. you could also back the entire bow this way without affecting tiller.
applying hickory or bamboo backing isn't repairing your bow, it's rebuilding it, but that is certainly a good option, too.
I would put some ca glue in fish and back it with something like pecan or hickory. That would be your safest bet I would think.
I know how you feel bud I have had four bows go south and just started on #5 last night.
Off to the bow shop for me and you :readit:
Stiks
Knots in board staves are disastrous. You've got 2. Start another but I would be more discriminating in board choice. No knots. Straight grain. Info on my site. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/
It is only going to get worse the more it is shot. Even if you back it, the inner core is cracked and will let go in time. Hang it on the wall and start another is what I suggest. Knots are a no no in board bows. I learned the hard way that you are better off to pay more money up front for a knot clean 1/4 sawn board, than to put 30 or 40 hours in a less than perfect piece of wood and end up losing it.
QuoteOriginally posted by PEARL DRUMS:
I believe that is a board Don? If not it has some serious ring problems. Board bows can be REAL buggers if the wood isnt just right to start with.
i know it's a board pd. i always read where someone is asking advice on chasing a ring and you always hear "make sure you leave material around a knot". it just goes to show that knots can be the death of a bow on boards too. i hope this one can be saved. don
Don't put JB weld on the crack, it won't do anything.
I have a fix in mind, thanks to all of your great ideas gang. There will be no JB weld used, thanks Sal. It's a long shot of an idea, but based on what i'm hearing, the bow doesn't have anything to lose.
It's frustrating to see this bow have something like this go wrong. I wish I can show you guys the end grain, it was pretty much straight vertical, with maybe 3/32" between grains. Perfect specimen for a board bow. Somehow, I overlooked this knot. Oh well, if you ain't learnin you might as well be dead!
Report to follow.
Let us know how you fix that, fish. I've been helping a neighborhood kid make a board bow and after reading your post we experienced the exact same thing. A slight crack at a spot with two tiny knots!
I'm considering a very thin hickory, or red oak backing before going further.
Stan
I got working on the repair last night. A tension style dovetail tenon if you will. It sounds crazy cause I don't know how to describe it. I need another night with it, and I may be able to test her tomorrow night.
I always thought that self bows could only be done with "flat-grain" wood? I would love to know... I make laminated bows and have the urge to try a self-bow...
I would put three layers of sinew on the back with hide glue
QuoteOriginally posted by fish n chicks:
...the bow doesn't have anything to lose.
Yup, might as well experiment a little. That's my newly revived motto! :knothead:
If I were to fix it, I would cut a V shaped notch where the knot and crack are and would replace it with a fresh V shaped piece of wood and glue it with urac.
Well fish I think I will just watch and see what you come up with.
So I learned two major things during this repair. The first lesson is, that the very first thing I ever forge, will be a marking knife.
Second, my mortising skills suck pretty bad.
Now, here's what I did to try to fix this issue. I actually received my shop notes magazine about a week ago. One of the projects they went over was how to use butterfly keys to repair damaged stock. So I used that idea to fix my bow.
Considering that the area in question will spend most of it's life in tension (must be married or something) I had to remove stock and try to keep the fix from popping out. So here is what I did:
I used a piece of lignum vitae for the repair due to it's specific gravity and density being more than the red oak's. I made it slightly larger than the piece. Looking back, I would've made it with "fingers" that wove into the oak's fibers.
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0049.jpg)
Mark it with a marking knife. I had to use an exacto. NEVER AGAIN!
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0053.jpg)
Mortise it. I used a 1/2" chisel. I wish I had a 1/4" but did what I could with what I had. And I will be buying a new set of chisels soon too!
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0054.jpg)
Press into place with clamps and thin stock to apply even pressure, after applying glue of course. I went with TB3 cause, well, it's what I had. I'm sure epoxy would be the proper adhesive.
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0055.jpg)
I used a finger plane and sandpaper to clean it up.
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0057.jpg)
Then I wrapped it with hemp chord soaked in glue-water, and wrapped it like a cast. It dries up like a cast too.
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0058.jpg)
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0061.jpg)
After the glue dries, you get a hard cover over your repair, which will give with the tension and compression forces applied, but keep your limbs from splintering.
That's the theory anyway. Time will tell if this holds true.
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0064.jpg)
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0066.jpg)
I managed to string her up and shoot a dozen or so arrows through her. Still shoots like a dream, but my tiller was thrown off a touch. I don't know if I will do anything about it at this point, if I can do anything at all.
(http://i872.photobucket.com/albums/ab283/jonnoocha/IMG_0068.jpg)
So, so far it's a survivor, much like a lot of us that society has written off. I'm hoping she takes a finish well, and to have her in the mail some time next week. Hope this may have helped some. I know without the TG, this repair would not have been.
Fish to even out the tiller, do you think adding a wrap on the lower limb in the same spot would help. Just a thought.
well put a few hundred through her and see. Good job either way.
I think the tiller looks pretty good. I would put a matching wrap on the bottom limb and call it good. I've got a hickory bow that pulled up a huge splinter and I put a wrap on it kinda like you got there and I've shot hundreds of arrows through it and its still shooting great.
You did well. Very nice. Jawge
Thank you guys! I'm just really glad she's still with us. I've got her on the bench drying between finish coats now.
At this point, I'm just gonna leave her the way she is. That pic above is actually my first, and only visual of the tiller since the repair, and it was done with a timer on the camera, and me rushing to get the pic off. I don't want to mess with the tree at this point either. Just working it manually has really helped. After it's finished, I'm going to take a bunch of money shots and see what she looks like.
Thanks again gang!
So my repair didn't make it 50 arrows. The bow busted right at the repair. In all honesty, I was foolish to think it would work. Most of you called it too. In the end, a true repair would've been to soak the crack, and then back the bow. I DO want to thank you all for trying to stear me in the right direction.
This was a half ass attempt that cost me a decent bow. So, my final answer is THIS METHOD DOES NOT WORK.
(http://i872.photobucket.com/albums/ab283/jonnoocha/Bowyer%20Stuff/Tradebow%202011/IMG_5663.jpg)
fish now we all Know so the knowledge we all gained is something the we can put in our collective hats.
Plus now we get so see some more of you wonderful tips and knocks.
Trust me I know you pain. I have only tried making 3 bows and only one has worked so far. I know you will just settle in am knock the next one out of the park.
When I saw the kind of thread you were using and the glue you soaked the thread with I thought " that isn't going to hold".
Filling the crack with urac if possible, super glue if it is too tight followed with braided nylon serving thread soaked with all the super glue it will hold has worked for me. Done at least least 5 repairs like the one below, all held.
(http://img.photobucket.com/albums/v181/ekrewson/bow%20making/copperheadbackcrackwrap.jpg)
oh dear- sorry man!!