Hemlock Branch Bow

[PlanB]

Shot the bow already. I wasn't planning to I braced it and it looked pretty good, so I pulled it back a bit and it still looked good. Kept pulling it back further and further. Still looked good. Nocked an arrow just to get read on the length. Still looked good. Didn't feel strained. Did feel a lot like my other bows, which are 40# 27" generally. So what the heck, go outside even though it's raining, and you've probably got a green bow, the heck with set, its a darn hemlock branch. And, well it shot where I aimed it. What the heck!

I never even got it on a tiller tree. All I'd done is rough it out, feeling for the taper all along both limbs (which are totally different in character) and done some eyeball floor tillering. That's it. It wasn't like regulation bow building at all.

Is it perfect? I don't know. Is the tiller what it should be? I have no idea. I haven't even seen it drawn from afar. I still want to work on it some more, and get some actual measurements. But this IS a bow. It's not just a branch any more. The branch wanted to be a bow, because it sure as heck was the easiest and fastest bow I ever made to any particular spec. The only thing I did was complicate it unnecessarily by steaming out a curve (which has since returned). I didn't even think it was ready to be a bow yet. It just was.

[RyanY]

Glad it got to send an arrow. I was worried this had Christmas tree bow written all over it.    Success! 

[WhistlingBadger]

That is really cool.  Amazing what you can do when there's not much to loose.  I'd love to see a full draw pic if you get around to it.

[PlanB]

Thanks Ryan, Whistling Badger. Here's just a couple of quick photos of the bow rough floor tillered, as mentioned. The upper has some kinks and reflex between branch knots. The lower curves outboard as well as in line.

[RyanY]

Too cool.

[PlanB]

PS  I'm standing in front of the downed hemlock it came from. Just a pile of green branches in the background.

Upper limb close-up:

[PlanB]

Steaming a little setback into the handle:

[PlanB]

I put a simple coarse string handle on it, a coat of linseed oil, and a knotted long string and shot 50 arrows through it this morning to get a feel for how it's handling now. Weight is dropping only about gram per day at present 559 grams.

 I was getting nice shooting consistency with the branch butt-end up, so I might adjust the handle position some. Otherwise it's a perfectly good bow. I see no problem so far with using E. hemlock branch wood for a selfbow, but time will tell. I'll update as I shoot more with it.

If I were to do it again, and I probably will, I'd look for an upward bending branch, and one that didn't have side bend. This one was neither, though it has produced usable bow anyway, but it was just a salvage branch from a downed tree. Hemlocks grow with upward bending limbs from about the middle of the tree on up, and downward bending limbs near the bottom. One possible factor in wood quality though is that the lower limbs will have more and tighter rings and be thicker than the newer higher limbs which are also getting more light.

If you imagine the snow loads on these lower limbs it's pretty impressive that they got through 50 northern winters (in the case of my bow) loaded with snow and ice at the end of a 12 foot lever. Hemlocks mainly carry needles and side branches only on the end of their long pole-like limbs, not distributed along their length, forking, like a spruce limbs.

That's a lot more bending stress than a 20 year old vertical sapling gets, and the wood is much different and is designed by nature to carry very different kinds of loads. Whether or not hemlock boards or staves would make good bows, I don't know. Maybe not. But a 1-1/2" inch thick hemlock branch with 50 rings is I believe a different material altogether.

[willie]

looking nice!

do you have a way to measure poundage? like at 2/3 draw? it should pick up weight as it dries, and maybe too dry might be a problem.
If it is overbuilt enough, and shoots at a poundage you like, you can watch the poundage at 2/3 draw and thereby the MC, putting it someplace cooler/damper if needed.

[SpringyWoodPassion]

PlanB! CONGRATS. I've been following your progress too and couldn't believe you put so much work into this unassuming branch that in the picture looked EVERYTHING but a future bow. I would not have bothered to go through all this with such a "twig" and this is what I would have missed.
What you've done is so inpiring, really. I'm pretty sure this is how the hunter/gatherer thousands of years ago would make some of their bows.
Excellent!

[PlanB]

Thanks SpringyWoodPassion, it really wasn't much work, and the steaming probably wasn't necessary if a better branch had been selected. I also would have wiped on linseed oil as soon as any wood removal was made to lessen the effect Willie pointed out earlier, that the branch will warp toward exposed heartwood. But again even with less than ideal wood selection and wood treatment, it has still made a good bow.

Willie, the bow lost 3 grams last night, so it's still drying. We'll keep reporting until it stops and seems fully dry. I do think the linseed oil has evened out the drying rate across the wood because the deflex isn't increasing. Also I shot two dozen more arrows out of it this morning, full draw, and there was no measurable set. Accuracy was really good (in my hands anyway). I'm really pleased with that.

I'm still looking for my darn bow scale, my beeswax, and my serving spool, all of which I squirreled away someplace unknown 5 years ago when I stopped building. I'll find them, as soon as I wade through a bunch of boxes. it's bugging me.

Meanwhile, in feel, the bow stacks, which is to be expected in a deflexed bow of this type, since braced string tension is low or even slack. On my bow I've set it up with a little braced tension, I can pluck it and get a bass note, but it's a low tone compared to my flipped tip regular bows. And the initial 1/4 draw has comparatively low string tension. So the 2/3 draw figure is going to be on a curve somewhere.

I'll just full draw it with the scale when I find it. I'm not physically worried about doing that. I have 75 arrows through it and continuing, the bow feels quite solid and isn't taking set. The stack isn't extreme, and it doesn't feel like I'm pulling to a limit.

My only worry is that when I do find that scale I'm going to learn that I'm weaker than I was 5 years ago, and what I think is forty pounds ain't!

[gifford]

kudos on seeing a branch and thinking - there's a bow in there. You stuck with it and got a good shooting bow. Again, well done.

[PlanB]

Thanks Gifford.

Willie, 34 lbs @ 27" so far. So I'm 6 lbs short.

It's still drying 555 grams now, 4 grams in 3 days, a little less than 1% MC drop.

[PaSteve]

Interesting build. Thanks for sharing your process and results.

[PlanB]

Thanks PASteve.

The bow is now down to 552 grams, and draw weight is 35 lbs.

While drying does help increase draw weight, I think it's close to dry now. On the negative side drying also increases deflex and brace height, both of which reduce draw weight at 27". If I could permanently reduce deflex, particularly in the branch's butt limb I'm confident the bow would hit the 40 pound draw weight goal. The butt limb had the most wood removal, and that made it more susceptible to uneven shrinkage of heartwood vs sapwood.

My thoughts on steaming a semi-dry hemlock branch bow are, it tends to relax over time, because it's essentially rehydrating a section, and that section dries again and over time warps back quite a lot of the gain. Steaming does have some lasting effect, but I think you lose more than 50% of what the original gain was.

I haven't tried dry heat on the bow, and I don't know what the effect on softwood, or branch softwood would be. I may try it just to see if it will help. I've done it successfully on hardwood bows of elm and black birch, and it also worked on the challenge wood cottonwood bow, just no idea how a hemlock branch will act. There is so much lignin in the the hemlock branch's belly wood, and that is so hard already I do wonder whether it's just going to add brittleness.

I do feel the bow is plenty strong enough right now, and has good flexibility, it doesn't feel marginal at 27" draw, I could probably draw it further without problems, but 27 is my draw length. I think the wood left in the bow easily has 40 pounds in it, but the deflex is too great to get there at 27" draw.