Hemlock Branch Bow

[PlanB]

No change in physical weight today, or less than a gram, but the deflex in the butt limb and brace height has increased to the point where I want to try to reduce it.

I'm trying to decide whether to take one more shot at steam bending it, or whether I should now try dry heat. I think the bow is near equilibrium moisture content.

I don't have a lot of confidence in the permanence of any degree of steam bending this particular bow at this point, but I don't think one more try will harm it. On the other hand the physical changes from dry heat bending it, whether they turn out to be positive or negative, are going to be structurally permanent, and the bow could be ruined.

Well this is an experimental bow anyway and we just want to find out what happens with hemlock branch wood so I guess dry heat bending will at least provide some information no matter what the result.

[PlanB]

I dry heat bent the butt limb without any problem. It was easy and I just used a straight 2x4 on edge with a single rope lashing at the end as the caul without trying to over bend it to account for spring back. I didn't try to remove all the deflex or add flipped tips, etc. The intention was just to reduce the deflex and brace height some. It's still an attempt at a very primitive bow style, using a softwood branch, and a minimum of form manipulation.

The wood really responded easily to heat -- I could feel it relax as I heated the limb and pushed down on the bow handle. Eventually the handle contacted the form. I applied heat for the middle two thirds of the limb. The tip was up a little because the lashing wasn't absolutely tight. I simply heated the wood to a golden color, not brown as in regular heat treatment. But the limb did retain most of the straightening treatment after it cooled. I also heat treated a small section of the other limb.

My guess is heat treatments removed about 3" of deflex across the whole bow. In other words with a slack string brace, the brace height moved toward the handle 3". It now will require a fair amount more tension to spring the string onto the bow. The heat treatment also removed a lot of the side bend of the butt limb.

I weighted the bow immediately after heat treatment and it had lost 2 grams. I set it outdoors (40 deg. F) to rehydrate, and it gained 1 gram in about an hour. I'll weigh it again in another hour.

The check in the butt end (mentioned early on) is a little more apparent now, but it still looks quite fine and shallow, and I don't think it's going to affect the bow. It may close after rehydrating.

The questions now are, has the draw weight been increased? Is the straightening relatively permanent? Is the belly now more subject to chrysalling? Is the bow now weakened or made brittle?

[PlanB]

Made intended weight and draw.

[PlanB]

Below are the present configuration, unbraced and braced.  I shot 100 arrows through it yesterday and today, it's quite accurate and I like shooting it as much as my favorite elm stave bow.

It's definitely and oddly asymetrical; the thicker shorter and more massive butt end is actually less stiff than the more delicate branch end, and I shoot with that shorter end up, and the handle well above the bow center. The upper limb also curls to the left. This bow is not going to win any contests for tiller or appearance, but, in fact as it stands now, the bowstring is perfectly center shot over the top of the handle, and arrows fly consistently without wiggle to the target, and even though the lower limb is longer it is stiffer, and everything feels right.

I'm certain with a better limb, or a more fastidious bowyer... or both, an eastern hemlock branch bow could be a thing of tillering beauty, but for me, I just like this bow as is. It is what it is -- a branch lopped off a downed tree that shoots an arrow well, and seems quite rugged. I really don't feel like it's close to overstressed, and I'm pretty sure more weight or draw length could be had out of this same bow. But I just have a feeling that this will be a long lasting bow that's easy to string, retains weight and shoots accurately. We'll see. Anyway yup, hemlock branch is a good bow wood, Self bow wood, it is, in fact.