Primitive Archer
Main Discussion Area => Bows => Topic started by: Manolovis on June 21, 2021, 06:03:52 pm
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Damned !!!! Working on a take down looking really good. Got it to bend to about 3”. Then decided I would recurve the tip and heat treat before going further. Anyway steam the limbs for about 45 min. Bend the first one no prob bend the second and crack. The sound of despair!
Crack is on the belly 2” under nock. Runs for about 2” and at the deepest is 3.5/ 4 mm. Thickness is of the limb at that portion is about 10or 11mm.
Filled it with super glue. Is it worth the repair with wrapping it or with underlay and overlay or should I start a new limb?
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Post some pictures so we can see the damage.
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Yep, pics needed, but underlays work well on the tips as a rule.
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A crack or a check?
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A crack, transverse from one side to another but fractured extend for about 2” length wise. happened as I was bending. I ll try to post some pictures later
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hopefully we can see something
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why does PA make is so hard to load pics.. absolutely a joke.. sick of it.. I gave up posting pics here..gut
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I have no problem posting pics. If you use the right format with your pic carrier and the right resolution it shouldn't be a problem. I use a Chrome Book and don't own a smart phone. I think figuring out the proper methods for smart phones should do the trick.
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I don’t use a hosting service. I use a free download. “Gimp”. You just select the physical size, and then set the file size at less than 200kb. Bam. Easy peasy.
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Can you guys open the files ? Or should I try load differently
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I can’t open it but that don’t mean anything, I am really bad at this stuff anyway, if it’s not just a picture I will always have trouble. Pappy
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hope it works now
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Not that it would help now but if you chased a ring on the belly side that should help with cracking when bending in recurve.
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My question would be first, how far does the crack really run? I would think you can super glue it together, and then add an underlay, but if the crack spreads into the bending section, no bueno. I hate messing with that kind of issue where you just don’t know the extent of the damage.
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jake: i ll be more careful next time with ring chasing. hard to see now because steel lam i used stained the wet steamed wood when i bent it , but i think there was one ring at the most critical bending portion.
bob:by " how far does the crack really runs" do you mean if crack carries on where we can t see it? i didn't planned to have that section bending ... that s why i was wandering if still worth the repair. but i m worried that crack is too deep and the back will fail regardless of underlay on belly....
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Just depends on wether you want to spend your time working on a repair that may fail, or spend your time working on a new bow. That may fail. Small repairs, I’m down with it. The more questionable the outcome, the less I care to invest time in it. It’s a hobby, and it’s your time so no wrong answer.
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I might be looking at it the wrong way, but it looks almost like a de-lamination started by a failure of early wood. Not a big deal. I would simply grind off the belly portion and add a thick underlay, making sure the tip does not bend at all. It better be long than 6 inches. I might even add a long overlay on the back to make really sure. If that still fails, I can simply v-splice a siyah, then also add the underlay and the overlay as well. That will make the tip thick and heavy. I am not sure whether that kind of severe recurve is necessary.
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I think i might give it go...
I might be looking at it the wrong way, but it looks almost like a de-lamination started by a failure of early wood. Not a big deal. I would simply grind off the belly portion and add a thick underlay, making sure the tip does not bend at all. It better be long than 6 inches. I might even add a long overlay on the back to make really sure. If that still fails, I can simply v-splice a siyah, then also add the underlay and the overlay as well. That will make the tip thick and heavy. I am not sure whether that kind of severe recurve is necessary.
scp would you grind down to the the fracture/delamination line to glue le underlay?
if it fails i ll make a new top limb...
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Yes, grinding down to the crack line would be the easiest way. You need to make the tip thicker than it was, even if you have to add a couple of thin and long underlays. Just study Eric's pretty photos of broken tip repairs. You need to make the tip stiff enough not to bend at all.
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With no damage to the back an underlay would be the best fix, the crack is in a non bending part of the tip so a failure is not likely. For the best result you need to heat bend your patch to perfectly match curvature of your bend exactly, you can make the patch slightly thicker than you need and shape it after the glue up. File off the cracked wood, use a sanding block to make the ground off portion as level as you can, feather your flat place back to the limb gradually. I would superglue the crack closed before you start grinding the belly flat just to keep from splintering the crack more, you are still going to grind off all the crack but need to stabilize it before you start.
You will need a form to bend your patch, I made several for the fix in the picture before I got it right, I used dry heat for the bend. Put your patch on the limb without glue and hold it up to the light, you should see little or no light between the patch and the limb before you glue-up. Your fit will be easy because the limb will pull in to match the patch or vice versa. With a double patch like I made the first was easy but the second had to exactly match the bend created by the first.
All you need is the underlay part of this type of patch.
(https://i.imgur.com/3YeVx1l.jpg)
The bending form;
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On the above fix I glued all the splintered parts back together before I started the grinding process.
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That s awesome Eric thanks for all the info. That gives me hope that not all is lost
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I have had luck with a similar type crack by mixing some epoxy (not a thickened one like EA-40) but something like West 105 ... you then need to warm the wood around the crack and also very briefly (because it will set up much faster) warm the epoxy. You can do this by putting the cup of epoxy in hot water.
Then the epoxy becomes very runny and will penetrate a crack much better. As the wood cools it also pulls the epoxy into the crack.