Primitive Archer
Main Discussion Area => Bows => Topic started by: JWMALONE on March 08, 2018, 01:26:00 pm
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Hey guys got a serious problem I think. After 75 shots I can feel the glue lines in the riser handle pieces I glued on, they are no longer smooth. I glued it up and let it sit 24 hrs then glued up the boo backing. Its the are on the belly were they taper don into the belly proper.
What the heck can I do, if I keep shooting its gonna blow I'm afraid. really need to save this bow. If I heat it off (tightbond) I'm afraid it will affect the backing. There is 9/16 inch of ipe under it don't know if that enough to turn it into a d-bow. Any ideas?
(https://i.imgur.com/RuwmI0vl.jpg)
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cant see it but I can feel it, this is the area.
(https://i.imgur.com/XIAyPFil.jpg)
(https://i.imgur.com/XIAyPFil.jpg)
(https://i.imgur.com/faYPvfEl.jpg)
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Grind it off and glue up some more lams of a more suitable glue. That's typical of TB btw.
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Is that hickory sandwiched in there? It looks like it. If such is the case, it might be swelling from moisture intake. I have an ipe very similar with a handle laminated from hickory and ipe, during certain times of the year I can also feel a bump and other times I cant.
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Its white oak. Its been sealed
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Read the thread linked to and pay particular attention to DWS posts. You need to follow that after switching your glue. Your fades still have a step rather than flowing imperceptibly into the limb.
Use the same wood(Ipe) for the intermediate lam so that you know everything is on the same page as far as how it reacts to any kind of stress.
http://www.primitivearcher.com/smf/index.php/topic,62336.15.html
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Pat M, that's the way ive always done a glue up. My specs are almost exactly like DWS used in the one post, 9 inch riser block, 4 inch handle 2.5 inch dips or fades. I sanded it back some, it will not sand smooth, i saturated it with super glue sanded as smooth as posible and shot 25 arrows through it, no change.
There should be plenty of nice even transition from riser to limb so that its not over stressed, like DWS mentioned. This is the first time ive had this problem. Its not noticable to the naked eye, but i can feel it with my thumb nail, and knowing its there bugs the crap out of me.
Thanks guys, im gonna shoot it and see what happens, if it blows ill post it.
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DANG!
Looks like your dips dip into belly a decent distance. That's good thing.
Ya used thin lam as 1st part of riser build-up. That's good thing.
So I'd guess issue is the glue joint. A gap betwixt belly and lam and/or not enough adhesive.
I have gotten in habit of using epoxy (Unibond) for that joint. Then tb for remainder of riser build-up joints.
Hope it works out for ya!!
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I would be curious to see the bow strung up, if you can.
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Thar she is. Ive been glueing with tight bond for 30 years, not bows but. I'm not above making a boo-boo, maybe its just a bad glue line?
(https://i.imgur.com/cnL0vaTl.jpg)
(https://i.imgur.com/ccQnxdml.jpg)
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Man, I can’t see that that handle / fade area would be under enough stress to pop those lams. I can’t see the pics in detail, but is it only where the belly of the bow meets the maple, or is it on both sides of the maple lam?
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Its on both the bottom were it meets the belly and the top were the second piece of ipe is glued on. On both ends of the riser. I figured it was flexing maybe not, but I don't understand why it wont sand smooth and stay smooth?
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How old is the glue? By chance could the glue have been exposed to a freeze? Have you had other successes from the same bottle? Use acetone?
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Is what is happening referred to as creep?
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Glue is good, keep in a heated area with my paints and other stuff that cant freeze. Ive had success with other bows same design with this bottle.
Not sure what you mean by creep, think I do. My other bows I can run my thumb nail down and feel nothing. Maybe I didn't have enough clamp pressure?
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This quote is off of a different site
“ Some glues deform over time and appear to squeeze out of the joint a little, leaving a discernable ridge at the glue line. This is called "creep." I used Tightbond III to laminate my bench top three years ago, and I can now feel a tiny raised ridge along each glue joint, I.E., creep.”
Read another place that it sometimes happens on highly stressed joints.
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64" is about the longest bow that I use tightbond on the handle for. Smooth on is stronger, it looks like you did everything right. How long is your bow? Is your ipe 3/4 thick at the handle?
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It's creep TB is not a 'hard" glue so you'll always see that on edges that are exposed to expansion/contraction and shear stress from bending.
Are other bows this same mixture of materials?
In the previous post DWS saif he typically used a longer riser and fade area. That will always help in this situation. Why not give yourself some peace of mind and be totally happy with the bow rather than fretting and checking the glue joint every time?
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Pat M, you are correct just never had that issue, it scared me. I can live with it as long as it shoots good. This is the first time ive use either of these materials, ill know next time.
Thanks Guys.
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JW, sort of an aside, but I do love me a power-lam for bows like this.
One problem with making stacked sandwich with contrasting woods is they often have contrasting qualities. Like, some just sand so easily you can develop a dip or bump at the fades where they join. Some may expand with humidity like Pearl mentioned. Some want to cup once water based glue touches them, then shrink back when dry (goncalo alves does this so bad I started dunking the whole lam in water). All kinds of things.
Anyway, it's very likely creep or a shift like PatM says from the stack bending or flexing, etc. the glue squeezing even more. If you have confidence in your glue lines, don't worry about it.