Primitive Archer
Main Discussion Area => Bows => Topic started by: IrishJay on December 22, 2018, 06:52:30 am
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So I fin the finally made a working bow. It ended up a hair lighter than I wanted it, and it took some set, ending up with string follow. Is there anything to be gained by heat forming the limbs back to straight, or even a hair of reflex? Or will they just return to their current set as soon as I draw it again? Belly is already toasted, now is red oak backed with linen, linen was applied with polyester resin.
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181222_085341_zpsj1mxniq5.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181222_085341_zpsj1mxniq5.jpg.html)
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If you heat treat them in reflex they may keep a little reflex or come out straight unless you damaged the belly cells too much.
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Am I correct in assuming that will add a couple pounds of draw weight?
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varies. I have gotten increases from about 1.5 pounds to around 5 pounds. Wouldn't hurt.
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3 to 4 would put me right where I want to be. Bow is going to be a gift to my father, he has bad shoulders so I'm trying to keep it light, but he has a pride point about staying over 40lbs.
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I would make a test piece before I heated it. I'm not sure how polyester resin takes heat. The back doesn't get too hot but sometimes the heat sneaks around the corner and it may lift the edges.
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DC, probably not bad advice, although I didnt see it until after I had done one limb. I cant see any issues with the resin so far, but shes still clamped to the form. I'll let you know for sure when I remove it.
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181222_110457_zpsu81uz2v9.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181222_110457_zpsu81uz2v9.jpg.html)
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:OK
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Does this count as a reflex/deflex bow? ;) But seriously the first limb took about 1" of reflex with no damage to the resin. bending the other now, then we'll see how much set it takes when I draw it.
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181222_114622_zpscjhfs9rd.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181222_114622_zpscjhfs9rd.jpg.html)
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First draw after heat treat, both limbs hand grenaded, when it let go it was at full draw and 2lbs LESS than it was before the heat treat.
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So I guess I should have left it alone.
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181222_131459_zpsmwxtu4bt.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181222_131459_zpsmwxtu4bt.jpg.html)
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Well, back to the drawing board...sorry to see that, but it looks like you are learning a lot! Next time, if it is close, just write "40#" in fancy script and call it good...
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You got too impatient. You have to let the wood re-hydrate for a while after heat treating and especially this time of year when the R/H is so low normally. Live and learn.
Now time to start your next one using the lessons you learned from this bow.
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the bow was pretty good as it was,,a little set not going to hurt anything,,,and a little set is better than no bow,,when we start letting the way the bow looks,,, dictate the design,, it can get dangerous,, but as said,, I have done the same thing in dry conditions,, so I am pretty conservative with my heat treating, and if the bow is shooting well,,,I usually wont do it for very little or no performance gain,, just to make it "look" right,, if the bow is a real dog and I have nothing to loose,, then I will try pretty much anything,, knowing it could cause failure,,
I get the feeling,, there is a trend putting too much emphasis on the way a bow looks,, putting the performance somewhere down the list,,that sometimes is not giving the bow a true representaion,,,of what it should do first,, shoot well and not break,, ok just one more thing,, I had a bow that was shooting well,, and thought I would heat treat the belly to get just a little more out of it,, but I thought I would ask one of the best bow makers on the site what he thought,, he just said no,,,
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If we'd thought of it I guess we should have reminded you before hand but we just can't keep track of everything. Next time do some research on what you are about to try. Something like "primitive archer heat treating" in Google gets a bunch of info. Still to bad about the bow. Good luck on the next one. :)
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Brad, the intent was more about adding poundage than looks, but you're right I was chasing a number and now I have a broken bow. The half dozen arrows I put through it it was shooting well. So I guess I learned a good lesson on when to say "good enough," because a 37lb bow would kill alot more deer than no bow.
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I'm sorry to here about your bow blowing up. That makes for a bad day. It's happened to me, trying to get a little more out of it. The good news is you learned from it. Move onto your next one and take what you learned and make a better bow. Most of all, have fun with the journey.
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sometimes shortening one,, you can get a bit more poundage with out heating,, I didnt mean u specificly about the looks,,, I have blown up so many bows,, I am not judging either,,,, just hoping to post something someone with less exeriece can use in a positive way,,sometimes when you shorten,, the bows takes a bit more set and offsets the poundage,, its just tricky sometimes,,,, even when everything seems great a bow can blow,, but the ones that work are so rewarding,, again I meant no criticism,, at all,,, :OK
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Yeah, I have 2 decent local harvested black cherry staves and I'm toying with which to start next one will make a 68" bow the other a 72".
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Started working a bendy handle from the shorter piece of black cherry. It'll be 68" ttt, 66.5" ntn. I'm probably just going to back it with resin and forgo the linen.
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I don't think resin by itself will do anything, especially polyester resin. I've never even seen Black Cherry but I've not read great things about it. Some have made bows from it, maybe they will chime in.
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DC, my thinking with the backing is that I've had 2 linen backed bows blowout, and the linen didnt really seem to do anything. The purpose of the resin would just be extra insurance against raising a splinter on the back. Although I have a nice unviolated ring on the back so hopefully........
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181222_194449_zpscboduust.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181222_194449_zpscboduust.jpg.html)
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Congratulations on your first bow. Set did not look excessive. All bows take set.
Only areas that do not bend can reverse set. On your bow looks like the last 8 inches or so. Can't tell for sure without full draw photo. Jawge
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DC, my thinking with the backing is that I've had 2 linen backed bows blowout, and the linen didnt really seem to do anything. The purpose of the resin would just be extra insurance against raising a splinter on the back. Although I have a nice unviolated ring on the back so hopefully........
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181222_194449_zpscboduust.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181222_194449_zpscboduust.jpg.html)
You're misunderstanding how a composite material works.
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Pat, I understand how composites work. The substrate (in my case linen) provides the tensile strength, the resin provides the hardness and the compression strength. I just think that the tensile gain from the linen (at least the cheap low thread count linen I have) is so minimal as to be negligible and that only real advantage I've seen to this type of backing is the "shell" that the adhesive creates to prevent raising a splinter. Obiviously with higher quality substrate ( better linen, silk, hide, sinew, glass cloth, etc.) the backing would bring much more tensile strength to the party, but I just dont know if the cheap linen I have is actually contributing anything.
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Soft backings don't prevent bows from breaking. They will help prevent splinters from lifting. Brown grocery bag paper is a good backing too but it won't prevent a faulty bow from breaking.
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That's more or less my point. If the purpose of this kind of backing is simply to prevent a splinter from lifting, then the resin will achieve that on it's own without the linen. If I were working with a different adhesive, like say wood glue the linen (or paper) would be necessary to give the glue something to bond to.
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The resin by itself I don't think will work. It's like concrete without steel, both together are strong but individually have weaknesses. I can imagine the resin cracking with continuous bending.
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Good point, I think I will use the linen just to be safe. I was thinking that the linen just adds mass to the limbs with out contributing and therefore the bow would be fast without. But, at this point I'd rather over build and get a working now than split hairs over a couple fps and end up with more fire wood.
Thanks for talking sense to me. (-S
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what about two layers of linen,, I dont think it will hurt the performance,, (f) and wood glue,,
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Brad, because the linen I have isn't long enough to back the whole bow I'll probably end up with 2 pieces that start at the limb tips and meet in the middle, with a third piece lapped over top that spans the midsection.
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well ok,, can you go to an art store and get a scrap piece of linen canvas,,I dont know where you live or if that might be a realistic source for you,, but linen canvas is very durable,, and would make a nice backing,,
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or just double what you described to have two layers
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So here's what I ended up doing, my linen was about 6" shorter the the bow ttt. So I ran one strip from one tip and it came within 6" of the other tip. Then i ran a strip the opposite way over top of this first strip. So now everything but the outer most 6" of each limb had 2 layers. Outer most 6" has only one layer. Then I laid the 3rd piece on centered on the bow so it reaches to within 3" of each limb tip.
So over all, our to 6" from the tips is 3 layers. 6" to 3" is 2 layers and 3" to tip is one layer.
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(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181223_172656_zps0jpnzr4x.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181223_172656_zps0jpnzr4x.jpg.html)
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181223_172700_zpsuzri0ncd.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181223_172700_zpsuzri0ncd.jpg.html)
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Resin is cured and I've got some of the edge of the backing sanded down. With 3 layers of linen the sanding is slow going, but hopefully it will result in a durable bow. Backing will get one more coat of resin after tillering is complete to give it a smooth finish.
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/Screenshot_20181223-225349_Gallery_zpsjwrdjmpd.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/Screenshot_20181223-225349_Gallery_zpsjwrdjmpd.jpg.html)
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I hope that backing doesn't overpower the belly and cause frets. At least with TB glue you get some give and I think 3 layers of linen is overkill.
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I'll find out when I start exercising the limbs during tiller. My guess is that if working backs like sinew or glass dont over power natural wood bellies I think I'll be ok. I got it braced from floor tiller prebacking, took about 35lbs to get it braced. So if I go slow I should have plenty of meat to get my 40lb final tilled on this one.
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My guess is that if working backs like sinew or glass dont over power natural wood bellies I think I'll be ok.
But......they do. Good luck! I hope you get a good shooter and like the fact that you’re forging right on after that first failure.
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And second, and third failures. It's been a bumpy road but I'm learning and moving forward.
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Why all the backing if ,as you state, you have a nice unviolated back?
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Everything I've read on black cherry recommends backing it.
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I had to spend a bit more time chasing an even tiller on this one than I did on the board bow, but it's my first stave bow to get to full draw without issue. Tillers looks a little off at brace, but looks better at draw. I think I'm going to have to live with it because I dont want to take anymore weight off. Set was not excessive, the stave had a fair amount of deflex to start with. Thinking about adding tip overlays, then it's just a couple more coats of resin on the back and some finish sanding.
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(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181224_232142_zpswt51ow21.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181224_232142_zpswt51ow21.jpg.html)
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181224_232158_zpshluo9cgi.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181224_232158_zpshluo9cgi.jpg.html)
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I still havent done the finishing work, but I got a nice cedar arrow set for Christmas today and it seemed like a good opportunity to try out both. Put about a dozen arrows through it, no bad sounds, no signs of belly checking. It's my first time shooting a bendy handle so it was a bit different for me, but over all I'm pleased.
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When was the wood harvested? I remember you getting some Black Cherry at the beginning of the month, it isn't that wood is it?
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Yeah, dried at 85° in low humidity.
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I would bet that's why it took so much set. You posted the first picture of it on Dec 11. If that's when you collected it that's two weeks.
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It didnt really take much set, it had most of that deflex in it when it was cut.
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Toasted.
(http://i61.photobucket.com/albums/h66/jayres83/Bow%20Pics/20181225_234343_zpsvvukqbiy.jpg) (http://s61.photobucket.com/user/jayres83/media/Bow%20Pics/20181225_234343_zpsvvukqbiy.jpg.html)