Primitive Archer
Main Discussion Area => Bows => Topic started by: danny f on December 31, 2012, 02:35:40 pm
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hi there, i have just done my first recurves on an ash board bow. it is 65" TTT 63" NTN AND 2" wide at the fades straight tapered to half inch tips. and it has lifted a small splinter on the belly where the bend is, i got the bow tillered to 15" draw before i did this i am aiming for #50-55 at about 25". i was wondering if i can just sand the splinter out or not? will it affect tiller? i am going to back this bow with silk i think, as there is a little run off in the grain. any advice appreciated thanks danny
(http://i493.photobucket.com/albums/rr292/dfee82/P1040971_zps5393575f.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1040969_zpsad2a220f.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1040972_zps1aa60906.jpg)
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You might be able to sand past that and still have enough meat for your target weight. But if it looks like they are going to pull out, rasp it down flat and laminate a piece of another wood to the belly side.
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The leverage at the tip is so low that I think you can take that out with no prob. You can then pretend you did it to reduce tip mass ;)
If you are really worried you can overlay a thin sliver of bood over the belly to beef it up, and then go V narrow (again saying it's a 'feature' to reduce tip mass).
Same thing happened to me on my first Osage with flipped tips >:(, the first tip I did wasn't too clever so it needed a thin belly overlay. I took more care bending the second tip.
Del
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I made one that did the same thing (Bodark) some years back. Couldn't sand past it so I did a belly underlay out of Juniper (ERC). Matched it up on both limbs. Shoots fine. Looks to me you can sand past it.
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cheers for the advice i think i will just try to sand it out rather than over laying. im hoping it will be ok. i also took more care with the second :). the other thing is they are now out of line so i will have to re heat them and line them back up. >:( you live and learn lol.
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I'd super glue it and sand it smooth after the glue dries.
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could i use wood glue or does it have to be super glue?
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That happens sometimes. If you are careful in your bending, using metal bands to hold the splinters down, steaming or heating the wood adequately, making sure the wood is at a good thickness for bending and is not overly thick, etc, than they usually do not go that deep. At least for me. Although there are some exceptions. For example, I just steam bent 90 degree recurves on 2 different hackberry bows, both bows had splinters lift when bending on the recurves, but both were easily rasped and sanded down. The last recurve I made before that had the same thing happen. But I also recently steam bent some 30 degree or so recurves on a mulberry sappling that was mostly sapwood. The mulberry was thinner, I steamed it longer, and the bend was alot less severe. But both recurves broke on the belly, and the breaks went about half the thickness of the limb. Added to that, the recurves didn't stay. I mean they stayed bent after I took them out of the form the next day, but when floor tillering, they bent back with almost no force at all.
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I'd suer glue it and sand it smooth after the glue dries.
+1
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dont look bad to me do what patb said and if it shows when done put a wrap on it, Bub
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I generally apply a belly lamination to all my recurves (which are always static/non-working). It would solve your problems, alleviate your worries, and look nice, too. Here's an example:
(http://i984.photobucket.com/albums/ae321/isaacscr/Trade%20Bow%20for%20Eric%20Thieman/HPIM5310.jpg)
(http://i984.photobucket.com/albums/ae321/isaacscr/Trade%20Bow%20for%20Eric%20Thieman/HPIM5318.jpg)
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Nice, 4est. A question then, would it be prudent to figure in a little extra wood during recurving knowing that you will take it off later to get rid of stressed wood there? Or is it the extra wood that IS there that is causing the extra stress? Meaning, is it better to take off as much wood as possible before recurving so the splinters don't happen? Capish?
thanks.
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Nice, 4est. A question then, would it be prudent to figure in a little extra wood during recurving knowing that you will take it off later to get rid of stressed wood there? Or is it the extra wood that IS there that is causing the extra stress? Meaning, is it better to take off as much wood as possible before recurving so the splinters don't happen? Capish?
thanks.
It is better to take off as much wood as the possible before recurving, verses leaving extra, especially if you are doing a dramatic recurve. You can leave it a little fatter than final dimension, but overall the results will be better the thinner the limb. Also round the corners of the section to be recurved, this will help a little in preventing a break at a sharp corner.
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Whoah, 4est, I'd be worried those tips would sting me! :o Those are cool looking. :)
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Just to add to what I said above, I meant it is best to get the limb to be recurved reduced in thickness as much as possible without actually getting it to dimension, not width. Width is always better to leave a bit extra, or more than a bit extra width, so that you can get a good alignment if the limbs bend off to the side for some reason. And I also think that 4est's static recurves are incredible, ;D.
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Thanks, toomany, that is what I thought--thinner wood bends easier for a reason.
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Hey forest, would those be what you would call Nels Grumley style static recurves? I don't see recurves like that often at all, so I am not really sure, but the ones I have seen like that, other than yours, were called nels grumley recurves?
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Them look like brush nocks to me! And mighty fine ones at that!! Nicely done forest! You should do a build along sometime and share your secrets with the rest of us. >:D ;)
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Like toomanyknots, I reduce the thickness of my tips before recurving. Actually, I TAPER them, heat 'em with heat gun, and bend them in a jig. Then, I apply thin laminations, increasing the curvature just a touch over the original heat bend. By tapering the tips, I get more of a bend with less work and less stress on the wood. The only problem is, you gotta put wood back (i.e., laminations). I think you can see what I mean in the pictures.
And yep...those are brush nocks, made popular in large part by Nels Grumley. They're not exactly like his signature (such as Bear Archery's Deerslayer model) but are certainly influenced by his and other bowyers' of the time. And they really do work...that is, they keep brush from getting stuck between the string and bow.
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And they really do work...that is, they keep brush from getting stuck between the string and bow.
Ohhhh, so thats why they call them that, ;D.
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thanks for all the help and advice everyone, and 4est those tips look excellent. will have to give them a go one day.
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Diddo what TMK said about rounding your corners before bending.Using dry heat [after a few days]on your recurves to temper them does help to maintain your recurve too.
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i have now sanded the splinter out and rounded the edges off. i think it will be ok now i have started tillering and nothing has cracked again so fingers crossed.
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well i got my heat gun back tonight of a friend so decided to put the recurve back in. i clamped the bow in and heated and slowly started to bend when it was red hot while keeping the heat on it, and it cracked proper, >:( its gone down one ring deep. so i thought i would file the rough part down and fill with wood glue. and i had some edge grain ash about 1.5 mm thick which was an off cut from another board (i new it would come in handy one day :)) i cut strips of this out and am goin to laminate with probably 3 layers and see how it looks, and then will probably wrap the area afterwards. what do you all think should it work??
(http://i493.photobucket.com/albums/rr292/dfee82/P1040992.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1040995.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1040993.jpg)
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Rasp it all away smooth and flat first, then add your underlays and skip the wrapping.
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would it make any difference strength wise as i have already put the overlays on now and am just waiting for them to dry. i dont mind wrapping as this bow is being backed and i would use the wrapping to keep the backing down too. thanks danny.
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I cant answer that. I believe it to be stronger replaced with solid lam's of wood. But hey, keep going and we will all know more about repairing tension cracks on statics.
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so im the guinea pig lol. i will wear a helmet when i shoot it for the first 100 shots. :)
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Hahahaha, if the little exercise wheel fits..................... For some reason I think of ERC when you mention Guinea pigs. Hmmmmmmmm, maybe next one ,eh?
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well the other recurve split more than the first i dont know whether the wood gets to dry while heating or if its just to thick to bend. i had to cut away this one and smooth it out and put in inlays then build up 3 more layers. they tips now seem very strong and i think they will hold together fingers crossed. i will probably wrap over the joints just to hide them as they look abit tatty. i have abit more shaping to do yet and will reduce them a touch so they aren't as bulky. heres some pics.
(http://i493.photobucket.com/albums/rr292/dfee82/P1040996.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1040997.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1050008.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1050006.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1050005.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1050009.jpg)
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How long are you steaming those tips? I wouldnt go less than 45 minutes.
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when i first did them i used steam and did it for about 30 mins. but i had to redo them as they pulled out while tillering. so second time i used a heat gun rather than steam. im not sure how long you have to heat them with a heat gun but they were very hot and i did the bends very slowly. then they decided to crack. i thought it may be the wood getting to dry. im hoping this will fix it if not its been a learning curve anyway.
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I really like how you fixed those tips with that plug/spice/overlay. I have the exact problem you are having with some woods, but not other. For me, Ash is just imposable to recurve, it splits open and the curves you do get pull out and elm likes to open cracks. Osage and mulberry are sweethearts to recurving. Those are sharp curves you are doing there. I know in ship yards that build wooden boats, they steam the wooden ribs, use a large metal strap as a back for the rib, and bend and clamp them to a caul. The strap keeps the back of the curve from opening up. You should try something similar?
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I steam mine for 45 minutes. I dont "set" them with dry heat and have never had any of them budge or pull out. I have made static bows with elm, hackberry and osage.
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i'm with pd, I go 1hr, on white oak I set with dry heat as it has pulled out,Bub