Primitive Archer
Main Discussion Area => Bows => Topic started by: Eagle Eye Eli on June 21, 2009, 04:51:09 pm
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I've blown up two Ipe bows during the floor tillering process. Both bows were backed with bamboo, one of them ended up with the Ipe thinner than the boo. (blew apart just passed the handle) On the second the bow, the boo delamed off the Ipe about 8 inches from the limb tip, I'm trying to reglue it as we speak with Bowgrip 100. The second bow is 3/8" thick at the tip to 5/8 " at the at the handle, and its 1 1/8 wide at start of fade to 3/8 wide at the tips. I've gone slow on the second one and i really don't understand why the boo and Ipe separated. Any advice that y'all could give me would be great. The first bow (hickory self bow) I made is still going strong..
Eli
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If you could post some pictures it would help us to give you an idea of what is happening. I suspect it is a glue problem. I have never used bowgrip so I'm not sure of the specifics, but many glues are picky. You need to get propper pressure without squeezing out all the glue. You also have to be conscious of curing temperatures and lots of other details. Justin
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i've used bow grip a few times. never really had a lot of confidence in it. i always understood it needed a thickener when used for wood to wood (or bamboo). try o some urac 185. its cheaper and better IMHO. I buy it a woodcraft, but you can order it direct from Nelson's paints online for about $12 for a pint. also pics really would help. i know someone here can help.
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Also from what I understand, Ipe is a very oily wood. Did you degrease it?
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Ok guys, yes i did wash the oil off using acitone and then let the Boo and ipe dry. I then used two hack sawblades to score both the boo and Ipe for a better wood to boo fit. Here are two photos of the second bow at glue up, and one showing glue line. I used the bow grip glue following Justin's instructions on his old web sight/youtube video.
(http://i629.photobucket.com/albums/uu18/E91_photos/100_1960.jpg)
(http://i629.photobucket.com/albums/uu18/E91_photos/100_1960.jpg)
Eli
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Oops here's the right pic. (http://i629.photobucket.com/albums/uu18/E91_photos/100_1959.jpg)
Eli
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well you are doing the right thing with the ruffing up of the surfaces
mix the bow grip 50/50,apply it to both surfaces,then wrap it with inner tubes
they work much better than the clamps,plus you get even pressure along the length of the limbsjust overlap the inner tube when wrapping.
if you have a heat box,stick the glued and wrapped bow in ther for 4 hrs at 160 degrees,then turn off the heat and let it cool completly
unwrap it and then it sit for a few days just to make sure.
i have done several this way with bow grip and never,and i will repeat never,had a glue failure as of yet
good luck
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well you are doing the right thing with the ruffing up of the surfaces
mix the bow grip 50/50,apply it to both surfaces,then wrap it with inner tubes
they work much better than the clamps,plus you get even pressure along the length of the limbsjust overlap the inner tube when wrapping.
if you have a heat box,stick the glued and wrapped bow in ther for 4 hrs at 160 degrees,then turn off the heat and let it cool completly
unwrap it and then it sit for a few days just to make sure.
i have done several this way with bow grip and never,and i will repeat never,had a glue failure as of yet
good luck
Ditto.
Not to be ugly, but Id find another glue than bowgrip 100. Ive made many bows with it and bake it at 160 degrees for 7 hours and then let it finish curing for 24 hours and still experienced glue failure. I have come to love titebond 3 for all ipe boo bows I make. Just degress it with acetone and keep the surfaces smooth and your life will be much easier. OR if you like epoxy, go with urac, smoothon, or arreo epoxy. Any one of them is heads above bowgrip 100. Urach or titebond will make your life easier because you do not have to bake them. They will cure at room temps. One more thing to consider, your boo looks kind of thick. Not sure. I never go over 1/8" thick with boo. I usually barrel tapper my boo from 1/8" to 1/16" at tips.
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hey i am not saying its the best
just saying,ive used it this way and its worked everytime for me
not saying that i am going to keep using it,just used what i had on hand
heck i dont even know how long i will keep making bows
like breaking rocks more,done need to worry about glue failures that way either
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One thing I learned about ipe bows and especially hickory or boo backed ipe...keep it narrow. With a 1" wide ipe board, backed with boo or hickory you can easily make a 100# bow. It don't take much ipe to make a bow!
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The one thing I see is the Bamboo is too thick. By the time it is tillered so a normal person could shoot it, there would not be much Ipe left. It does not take much 'Boo to back an Ipe or Osage bow. But less for Ipe
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:) You guys rock, Thanks for the help. I'll keep posting as i go along with each bow I build. Next project will be a hot box, and the purchase of TBIII. Oh yea I'll start tapering the boo.
Eli.
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Shape the boo to the bows profile, cut it out and reduce the thickness to 1/8" at the crown at the fades. You can go parallel from there to the tips or taper the boo from the fades to the tips.
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talk to knightd about bow grip...he hates the stuff and only uses Urac glue instead.
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Yes, Id go with the titebond glue, it is easy to get as well.....
Many people have 100% success with it, so, I think it good choice.
Ok, this is just a problem I have of recently...but I have had 100% failures with the titebond 3 glue using for the bamboo and ipe...
I really cannot find the reason. I degreased with acetone until there is no more oil, and the surfaces match perfectly, I use inner tubes to clamp....
Also, I have never had failure with titebond until I use for bamboo/ipe....
It look like cheese when it comes apart. Recently, I finished a longow, very unstress design at 50#@26, bow is 70" long. After a month of shooting, the top limb just slipped for 8" like rubber and came apart, almost snapping ipe wood. So far I had 4 more do same thing. Its weird because it happens while it braced, not even full draw....Is it the glue? I wonder if I just got bad batch....I really have no idea what it may be...I just go for urac for now.
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i have a full bottle of titebond the original, does that work well for laminations and backings too?
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Hi, I'll put my vote in for Titebond II or III. I haven't had glue failures except when I tried to use some weathered Ipe, and I think that was the wood's problem, not the glue. I don't degrease the wood, just glue as soon as possible after sanding the surface smooth on the Ipe and planing the bamboo to match. Ron
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whats the difference from I II and III?
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I believe there is supposed to be an increased water resistance as the numbers get higher. TB II is yellow and dries clear. TB III is dark colored and leaves a dark brown glue line. TB III blends quite well with the color of the Ipe. Ron
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so basically it doesnt matter which one for bow use right?
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I would suggest you try urac-185.. ;)
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All good advice above, but a little added advice. I would never clamp the back of a bow without using a scrap of wood or leather to protect the bow wood, those little impressions the clamp leaves will cause problems.
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Good eye Dano