Primitive Archer
Main Discussion Area => HowTo's and Build-a-longs => Topic started by: bobnewboy on July 23, 2009, 06:59:08 pm
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Hi All.
Its been some time since I did any making, bows or arrows, but once the bug has taken hold it is difficult to shake off 8) . Especially with all you guys posting pictures of such fantastic pieces of work.
I've made two BBO bows (both posted on here), and both have worked out really well, so I thought I'd try something different, and perhaps a little more technical. I decided that I would make a short reflex-deflex BBO bow, like a horse bow, which should be well suited to field archery here in the UK. I'm hoping for 50-55lb at 28 inches, but I know from reading posts on this forum that reflex bows are very difficult to tiller well, and can be rather deceptive during tillering. So fingers crossed, and here goes....
First job is to make a former around which I'll bend the recurves. I have a mildly shaped former for setting back the handle area on my previous bows, but this is not nearly tight enough to make the recurved limb tips I want. So I bought a large piece of 2x4, and drew a natural tightening curve on it. I cut it out and added some clamping holes. I then cut the curved end off, and screwed and glued it to the remaining piece of the 2x4, making a step upon which I could rest the limb being bent, hopefully keeping the bent section in line with the rest of the bow.
I then tried bending an example piece of 0.25" seasoned osage with dry heat from a hot air gun. This went well, but I noted that wood scorched a little, and that any loose fibres burnt and discoloured rather easily. See the first pictures:
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Okay, so having read some more on the forum about bending osage, I decided that it would be worth going ahead, but using some kind of natural oil to avoid the scorching of the wood - I chose olive oil as I already have some. I also got the belly piece to a floor tiller with a good thickness taper, and made sure that all edges and surfaces were rubbed down with sandpaper. I did not taper the sides of the limbs, so that while bending the tips I could be sure that I didnt pull the limbs to one side or the other, since it seems that limb tip aligment is a common thing to have to correct during or after tillering.
When cooled down and released from the former, the osage sprang back a little, but not much. There was still a little scorching, but this was no real problem as the affected wood would be removed when tapering the limbs. Here are the pics of the limbs being bent on the former:
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Having bent the osage belly piece, I found that the bamboo backing piece was fairly unwilling to bend into the tight recurve at the end of the limb tips. This is a nice piece of bamboo, with a good distance between the nodes (12" or so), so I wanted to use it. More reading on the PA forum...... ;D.
Ah, ok, bamboo bends with dry heat too! So I began by thinning the backing strip as much as I dared on my belt sander. The handle area of the backing strip is now around 3/16" thick, but the tips are around 1/16" - very thin but still seems strong. Then I used the former again, and gently heated the backing strip into the same curve. The bamboo sprang back a fair bit more than the much thicker osage belly, but it was now possible to fit the two together.
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So now I had the belly piece bent back into recurves at the ends, and the backing piece gently recurved. In order to make a R/D curly bow I needed to introduce some deflex in the handle area. I did this by dry heating (with olive oil) the handle area over a block with the good ol' heat gun, while tying down the limbs to the back of my recurve former. It makes for a nice shape.
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Now that I had the parts ready, it was time for the glue up. I prepared the wood surfaces by sanding with 80 grit sandpaper to give a fresh wood surface and a little surface key, and then wiped the surfaces down with plenty of acetone. This draws the oils out of the wood surfaces, especially the osage. I protect the backing piece by covering the waxy outer surface of the bamboo with self adhesive paper masking tape - makes cleanup after gluing much easier.
The glue I use is a resourcinol resin two pack type, originally known in the UK as Humbrol Extraphen, but now sold as "Polyproof Waterproof Glue". I measure it out by volume, and mix it using a piece of hooked wire in a hand drill. Its nasty stuff, so keep it off your hands and clothes. There is no solvent for this stuff once it starts to set! :o
I buttered both pieces of wood with glue, and then held the pieces together at the handle area using a g-clamp. I wrap the whole thing in cling film to avoid too much spillage. I then checked the alignment of the pieces, and then when all is OK, I begin the binding by tightly wrapping pieces of split bicycle innertube round and round the pieces. I start wrapping from the handle area outwards towards the limb tips. A good tip for UK-based bowyers - Tesco sell 26" wheel innertubes of reasonable quality for £1.86 each right now - I bought a few extra for the toolbox....The inner tubes provide constant even clamping pressure all along the glue line, and hopefully this avoids any dry spots or overclamping. At this point I set the bow aside to dry in my shed for a few days - it is nice and warm/dry in there at this time of year.
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Tick tock, tick tock. A couple of days later, I retrieve the bow from the shed. I peeled off the masking tape and cling film wraps, and the set to with my favourite scraper, a sami knife. Everything is looking OK, so I begin to taper the limb tips, but only down to around 1" wide at each end. Hopefully tip aligment will not be too much of a problem during tillering.....
A bit of flexing, or attempts to flex the bow show that it has gained a lot of draw weight. I think I will need to do some more floor tillering before any long string work. There's still plenty to do before that.
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The next job is to cut out and fit a thickening piece in the handle and flare area. I made this out of osage too. Getting a good fit takes some time, because the handle area is now curved due to the introduction of the deflex in the bow. I thin the ends of the thickening piece in the area of the flares / fades to an edge, since it is far easier to do before fitting. These edges will be blended into the belly piece during tillering, otherwise the thickening piece is likely to pop off later. Good thing the bow is now very strong ;)
The last job for now is to glue the thickening piece into the curved handle area, using the same glue type and process described earlier.
That's all for now! I hope to have another look at the bow during the weekend.
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wow! I can't wait to se how this bow turns out.
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Nice one Bob! Looking forward to seeing this bow shoot. Don't tell me you are going to place it in Primitive Class though - something this sophisticated has to go with the other curly bows in Hunting Tackle class!
I've just glued up some ipe and hickorybut I'm not quite sure what style it will end up in.
Keep us posted!
Stan
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excuse me,
when you heated in the deflex at the handle, do you mean you just propped it on that block, clamped down the ends (creating the deflex) and then just heated it and it held that shape?
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Hi Radius,
Yep, that was pretty much it. As many others have posted in the PA forum, osage bends well with heat. The wood springs back a certain amount once cooled, so the resulting deflex is not as pronounced as in the picture, but it is there. If the blocks are symmetically organised, the wood forms into a natural curve around the blocks when heat is applied evenly in the handle area. I did not include any glued-in Perry reflex in this bow, since the wood and backing will be stressed enough as it is.
I should point out that I'm making this up as I go along - it is my first piece of seriously bent wood. I am going on info gleaned from this forum, TBB1-4 etc etc. Half the fun is wondering what the bow will come out like.
Stan, the bow still meets the PV rules, even the proposed new set. >:D But we will have to see. Maybe I'll add siyahs to make it more primitive ;D
On Sunday I began a lot more floor tillering, because the bow as it came from glue-up out was probably at 100+ lbs at what would be a low brace height. Waaay too much osage for the intended draw weight, but it is always easier to lose weight than gain it. I think that this is also partly due to the fact that osage is edge grain from belly to back (??). I've been scraping like mad, and although the bow now bends by hand :o , it is still too much weight, probably about 60lbs at brace.
More scraping, bending, pics and text to come. Fingers crossed.
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i've bent osage before, too, but only by cutting it into bendable thicknesses and lamming them together in different forms. I just didn't think of pre-bending it, then adding the heat to make it stay. You really are making this up on the fly! That's how i roll too...
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Bob,
Whatever class we call it, this is going to be a first class bow if it all holds up (and I sincerely hope it does)! What weight are you aiming for? I'm assuming nothing too high as there are going to be a lot of stresses and strains in there....
Stan
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Hi Stan,
I hope it does hold up, but wont be too upset if it doesnt - that's the learning process isnt it ;) There has been a little creaking when working on it, but I'm unsure if that's my old bones or the bow - I've worked my way up to stringing at a low brace, but even that is difficult to achieve without both arms, both legs and a table right now......
I'm hoping for 50lb @ 28". That seems to be a reasonable limit for me and our field archery - no ribcages to burst through in the UK. Thus far I've left the limb tips quite thick, and instead of thinning them I hope to be able to use them (narrowed) as sort of integrated siyahs. I havent had much opportunity to work on the bow recently, because of the wonderful Engllish summer we are getting (I'm a back garden bowyer too!), but I will post more when weather and work allow.
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Hi All,
Managed to get a little time in working on the bow last night. After a load more scraping, the bow is bending a little at last ;D The osage shavings are up to my ankles!
The following pictures are the bow finally braced (gasp!) at a low brace of about 3". The other shot is the bow bending on the pulley tiller. It is pulled to 52lb at about 17" right now, so going in the right direction, but still a long way to go yet.
I'm hoping to get some more scraping done tomorrow, but as always I'm hoping for better weather than today :-\
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Bob,
That is looking absolutley lovely - I really hope this all holds up and works out it's going to be such a wonderful bow. Thanks for sharing this innovative build with us.
Had a bit of a disaster yesterday myself - the ipe and hickory I'd laminated and almost completely tiller delaminated completely - the backing broke in the process but the ipe belly wood is unscathed and I've backed it again with bamboo today. There were a number of contributing actors bue mainly I'd prepared the ipe glue surface with a finishing sander that someone gave me - it doesn't work! merely polishes the wood. Can't beat a good oldfashioned scarper and hand held sanding block for getting a good surface. Hope your osage glue line sticks, I hear osage can be an oily beggar to glue too.
Stan
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Looking Good Bob! That bow is coming along real nice! Awesome Job.
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Hi Guys,
Thanks for the comments.
Today I got a little time to get some more work done on the bow. I cant remember who on here coined the phrase, but it is so true - a little osage makes for a lotta bow. I have been scraping like its going out of fashion! :o It is obvious how much has been removed from the limbs when you see the handle area picture below.
Anyway, after what has seemed like a lifetime of scraping, the bow is now up to the full drawlength and just a little over weight - currently 56lb @ 28". Final sanding and shooting in should ensure that it drops to the 50lb @28" I was looking for. Physically, the bow is much lighter in the hand, and I havent narrowed the handle area nor the limb tips yet. The tips are still wide and quite thick when compared to the rest of the limbs, and so I feel that I should be able trim them down a bit narrower, which should help keep any hand shock down and tip speed up.
The glue line between the main belly piece and the handle thickening piece is a little disappointing, but hey, I need the practice. Purple glue on yellow osage is kinda obvious, but this contrast should reduce in time as the osage darkens. Also of course a handle wrap will help disguise that line...... :-[
I forgot to mention before, but this is the shortest bow I've made so far - 63" from limb tip to limb tip when unstrung. And boy is it ever bending at 28" draw. :o
Pics to follow below...
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One of the limb tips at tillering - no overlay as yet. I'll maybe use a creamy coloured horn slice...Note the grain orientation, and the tiny knot cut through here at this end.
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Side profile of the bow now
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The handle section, including a thick glue line, and a centre mark made with a sharpie. You can see how much wood has come out of the limb thickness.
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Full draw on the pulley tiller - 56lb at 28", sorry about the poor picture quality - i have a west facing back garden..
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Bow at a more realistic brace height, around 7.5"
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The attached file is an experiment. In fact it makes me a bit queasy to watch it, but you can see which parts of the limbs are taking the work.
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I wouldn't jack with that tiller anymore....Lovely arc. ;)
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Bob it's looking really good. Usually people only seem to attempt that degree of recurve with sinew backing (about which I know nothing!) To have kept all that lovely recurve in through heat treatment and gluing is a great piece of bowyery. Looking forward to seeing this one in the flesh.
Stan
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dude, that bow is sweet...i only wish i could make em that well...
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Thanks guys. Unfortunately work has been putting a squeeze on any time I've been able to spend on the bow, but in my idle moments (i.e when I should be sleeping) I've added charolais (spelling?) cow horn nock overlays (so pale, amost translucent), and made the first attempt at some handle shaping. I'm none too happy with the handle shape right now, but I have managed to shoot a few arrows out of the bow in my backyard, with the huge tillering string, and it seems good so far. No noise either, but that may be dampened by the thickness of the 25-strand B50 tillering string.
As an aisde, what kind of brace height do you all think I should be using? Remember that this is a BBO recurve with a deflexed handle. I dont want to go too high and shorten the bow's life unnecessarily, but I dont want it too low either......I'd be grateful for those who have made and shot this kind of bow to give a little brace height feedback :-\
Its my birthday tomorrow, so I have a whole days leave booked to be away from the office (yippee!). I am hoping to get up late and make one of my usually skinny strings (3 skeins x3 ply BCY450Plus), and serve it. Our club (The Company of Sixty) has a friendly field shoot on Saturday, so I may take it along to shoot a round with it for fun. Kinda depends upon the weather, as the bow has no finish of any kind and I wouldnt want to risk it getting damp. Stan, are you coming along to this one? I'd be glad of your opinions re tillering, draw weight and brace height too.
Thanks again all, keep up the inspirational ideas!
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Great thread & pics.
V pretty bow.
Del
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Hi All,
I've just come back from the friendly shoot today, having shot around 36 arrows out of the bow as it is, at the practice butts. The re-checked draw weight is currently approx 55lbs at 28", and the bow appears to be good with no problems so far. The arrow speed is excellent, possibly the fastest bow I've ever made. Shots are also quiet with no 'ringing' in the bow after release. Opinions differ as to the correct brace height at present, but it is looking like 7 - 8 inches will be best. I will finalise that when the bow is fully finished and shot in. Stan and some othe others who came along today also agreed that some wood could come out of the limb tips, whcih should further quieten the bow and reduce handshock, of which there is only a little.
I'll keep you posted with some more pictures as things progress.
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It is looking really good Bob. 7"-8" is a really high brace height. Most guys go for 5"-6". You will get better cast if you can lower the brace height. Justin
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really great job bob,was wondering though Im from over the border in scotland (now living in ireland though).where did you get osage from??
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Hi John,
I get mine from Flybow in Co Mayo, so you should be well placed in Ireland ;D. I'll PM you the website info, as I dont believe that they're PA advertisers.
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Hi All,
Update time. I have managed to get some more time to work on the bow. Jobs done:
- The limb tips have been considerably lightened,
- the string nocks formed,
- the handle built up with leather (but still not covered or finished)
- the whole things sanded and sanded
- the whole thing finished in several coats of poly spray varnish
- a new string made from 3 skeins of 4 threads of 852x in black and yellow, one end laid in, the other plaited and tied off in a bowyer's hitch (inspired by a Marc St Louis article.).
Jobs still to do:
- finish handle wrap, maybe in the tennis racket style
- shoot lots and lots (it is very fast).
Some pictures to follow.
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Note that I stupidly dropped a G-clamp on the bow after nearly completing it. That is the mark above the natural knot in the osage. I hope it will be OK
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A few more. That Charolais cow horn is soo translucent.........
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Looks great Bob! Those tip overlays look pretty cool. Very nice.
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Bob, it's gorgeous!
Are you at Co 60 0pen on Sunday? I'm not sure whether to go there or to the Roving Marks shoot in Kent, but knowing we could see your new bow might just swing it!
Good job.
Stan
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very nice bow. she looks fast.
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Beautiful bow!!! Looks great on the tilering stick! Have u been shooting it much? Great job!!!
Cheers
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that's a great one, man, one cool looking bow!
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Thanks for the comments guys. Sorry I havent posted any full draw pix or similar yet, but I'm working all the hours that the big guy upstairs gives right now. I'm posting this from a customer's office 8). Hopefully there will be some time this weekend to take a few drawn pictures and post them up. The bow shoots fast, and doesnt 'ring' like some other recurves, especially those made out of 'the other material that need not be mentioned here'...Having said that it isnt the quietest bow I've made, but I'm pretty happy with it for the seventh or eighth bow I've made. I've still to really experiment with the brace height too, but it seems OK at the moment.
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Wow love them curves!!! Nice job on that one!!! -josh :)
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Hi All,
Here are the final pictures. Full draw and the handle finish, which was best done with a fine black leather lace. Met up with Stan yesterday and shot around some. The bow is light in the hand, very quick and comfortable, around 52@28". The bow is 64" NTN, and and inch and 5/8ths wide immediately at the flares, tapering for the last 12" to 1/2" tips. Thanks for all the inspiration guys!
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Wow look how low your string angle is on full draw!!! I bet that thing is sooooooo smooth to draw!!! Nice!!! -josh
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Guys I've seen this bow and it is as awesome as it looks in the pics. Well done Bob and thanks for sharing your secrets on the forum!
Stan
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Oh, haven't seen this thread before!
That's a really great looking bow!
Good work!!!