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Main Boards => The Bowyer's Bench => Topic started by: Erik on January 13, 2016, 02:18:00 PM
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Hello
Just shot the first dozen of arrows with my newly finished bow.
However at some point I heard a crack and upon inspection, I noticed that the "handle overlay" had detached almost half of its lenght :(
(http://i168.photobucket.com/albums/u199/holmerz/BUE/IMG_20160113_192144.jpg) (http://s168.photobucket.com/user/holmerz/media/BUE/IMG_20160113_192144.jpg.html)
How do I approach this, I guess I should remove and try to glue it back on? I'm just afraid of ruining the glass laminate underneath.
How would you approach this?
In advance thanks
Erik
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I'd start a putty knife down into the separation from the end and tap it on through slowly.
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It came off because it flexed, that flexing has to stop in order for a re-glue job to work any better. A power lam would have prevented any flexing.
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Thanks for the advice Roy, it worked out perfect without damaging the glass laminate.
Concerning gluing on the piece again, 2 part epoxy is still the glue of choice for this job, right?
I'm not sure why it detached, bad gluing (ruffed up both surfaces with 60 grit sandpaper followed by cleaning off with acetone prior to gluing) or bad design (if the overlay covers a bending part that'll put a lot of strain on it!) or both?
All inputs are welcome
\\Erik
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I wouldn't consider using anything but the best quality slow curing epoxy. Smooth-on would be my go to. I would also shorten it, that way the feathered ends stop before the handle fades into the limbs.
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Thanks for the input Chris and Ben.
Chris, by power lam you mean a power glass laminate? I've used power glass laminate from Bogensport Bodnik (https://shop.bearpaw-products.com/WebshopB2C/Bearpaw_Power_Glass_Stripes/G-151?Origin=Navigator/)
Ben, I'll use 2-part epoxy (not smooth-on, but one I've used for the rest of the bow and flexible also) and shorten the top part of the overlay.
Thanks again.
Erik
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I've only seen them from wood or micarta. I know Benny boy has used them. Maybe he will come back to the thread and toss up a pic to better explain it.
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I had a bow where my flares didn't glue properly and what I did was reinforce the flex area with embroidery silk and gave it a epoxy coat. Wrapped it like I was serving a string. You lose some of the look but it worked so far. Not sure if that helps..
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The reason is the bow is bending there.
A powerlam is another lam (about 16 inches or so) that goes in the middle of the stack. It is thickest in the center then tapers to a feather edge at both edges. Like a stretched out diamond shape. These are used to stop any flex in the handle and then you can glue overlays etc on without any fear of them delaminating. You can make them from any materail because they are only acting as a spacer just like a core lam.
To fix yours you need to shorten your overlay and make it thinner near the ends. There is still a chance it will 'pop off' again because of the lack of a powerlam in your design.
If your glass hadn't gone up your riser piece that would also have delaminated.
If you wanted to use this design again you really need to use a powerlam. Problems like this almost always come down to a faulty design.
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Thanks Cody, I'll try that if shortening the overlay fails.
Thank you for the explanation Mike, I'll be sure to use a power lam if I ever try and build a bow with this design again.
I've shortened the overlay and glued it back on, and I'll shot it this weekend and we'll see if it last more than 15 arrows!
Thanks for all your input
Erik
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Ok, so I shortened the handle overlay and glued it back on.
(http://i168.photobucket.com/albums/u199/holmerz/BUE/IMG_20160117_132827_BURST001_COVER.jpg) (http://s168.photobucket.com/user/holmerz/media/BUE/IMG_20160117_132827_BURST001_COVER.jpg.html)
I've shot 50 arrows now and it haven't detached, so I hope it'll continue to be that way.
\\Erik