When to pull to full intended draw weight?

[TimberTinker]

Hi all,

New aspiring bowyer here.  I'm just starting out and I'm on my second board bow thus far. 

First bow story:

The first was a 64" red oak bow from a 2x1x6 board and it catastrophically failed around the fades at roughly 30 lbs.  Limb snapped clean off and sounded like a gunshot!  Luckily I was 20 ft away from the tillering rack.  I'm pretty sure the limbs were too narrow at only 1.5" and the design probably wasn't right with a thick handle section so no bend there and I had width taper start about half way down the limb and I was also tapering thickness.  I was trying to achieve about 40-45# weight... never made it there.

Second bow story:
Second is a 70" red oak bow from another 2x1x6 board using the same design minus the thick handle section so it's bendy through the handle.  It's looking quite nice but I'm afraid to draw past 30# given the first bow's fate.  Problem is I think I'm almost to a finished taper, and I haven't pulled to the full 40-45# nor have I pulled it to 28".  I've only pulled to about 33# at about 22" in fear of another failure and I'm pretty sure it's too late to try for 45# at this point without risking another failure.  I'm probably going to finish this one off at a safe 30#.


So my question is:  At what point during the process should I pull to my desired weight?  I need to get there much sooner, before I fear the limbs being too thin or whatnot.  I'm starting to understand the idea that you pull your desired weight at a shorter draw and then tiller to your draw length, but if I pull 45 or 50# immediately after floor tiller will I risk damaging the wood because there is still TOO MUCH wood on the belly or could it crack because there's not enough bend?  Obviously if I see an issue like a hinge or something I will stop pulling but where is a good place during the whole process to test the desired draw weight?

Any help would be much appreciated!!

[DC]

Always pull to the full draw weight unless you can see a problem that needs correcting, then only pull far enough to see the problem. Once you've got it sorted it's back to full draw weight.

[Pat B]

Agreed   

[DC]

Problem is I think I'm almost to a finished taper,

What do you mean by finished taper?

[TimberTinker]

Sorry, not sure if I used the term the right way, but by finished taper I basically mean I've got a really nice looking bend, perfectly even limbs down to the mm, no issues, etc. but I'm getting pretty thin near the tips and I'm pretty sure I've gone past the wood's potential to handle my intended weight because I never had the guts to pull to that weight early in the process.   

[Pat B]

Like DC said, draw to your draw weight from the beginning of the tillering process. That way you'll never come out underweight. So after a good exercise routine check draw weight every time you put your bow on the tiller tree.

[DC]

I'm not a board bow person but if you started with a decent board and have decent tiller a 70" bendy handle will go a lot further than 22". Can you post a picture? Do you have it braced to full brace height?

[SLIMBOB]

As an alternative, and this isn’t meant to contradict anyone else’s method, but I never use the scale early on so for me the draw weight is unimportant. I am focused on the bend. The tiller. Only at a short distance. Is the braced shape right?  Once it is pulling 15 inches or so with good tiller I take it to the tree and check the weight. Even then I won’t pull it to full draw weight. I just extrapolate what it will be based on the weight it’s gaining per inch. 5 pounds per 2 inches??  Where does that leave me at full draw. I just keep the tiller even and keep inching forward on the draw length. If I do my job right, I hit target weight a few inches short of full draw. A good bit of exercising on tree and it typically settles in with a bit of sanding. It’s not a better way, just a different way.

[TimberTinker]

Hi DC,

The bow is currently braced at about 5" and in the second picture I'm pulling it to 30 lbs at about 18-20".  I've managed since the picture was taken to get it to 33 lbs at about 22"

The right limb is a little lower in that picture but I've since corrected that with the last couple passes with the scraper.

The bow feels like it really doesn't want to bend further which makes me hesitant to pull more weight at this point in the process.  (33 is the max I've put on it, which is the reason for this post, I feel like I'm going things all backwards adding weight at the end of the process.)

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[Del the cat]

From that pic... it's not bending in the middle. Maybe you don't want it too, but it's easy to throw away a lot of potential limb length by having an unnecessarily long handle/fade area which just makes the rest of the limb work so much harder.
You are on the right track, because you diagnosed your own problem... (didn't have the guts to pull to full weight to start with).
Look at it this way... it will survive being pulled to full weight early on because it is thicker and it will only get to a short draw length so it won't over strain the wood. It also allows you to see any problems early.
The hard thing is getting your eye in, getting used to seeing the curve.

The bottom line is... if you want a 50# you have to pull it to 50# at some point, the sooner the better as long as you don't see a problem.
Del

[TimberTinker]

Del thanks for the critique!

This is why I turned here.  I see what your saying now that you pointed it out, it looks like I have a 16" handle when it was supposed to be a 10" bendy handle.  I can't get more bend because I'm not utilizing the full limb.  I think I was too focused on getting the bend that i already had perfect I missed the elephant in the room.

Thanks a bunch everyone!  Still don't think I'll hit my target weight but this could still be a decent board bow in the end.

[DC]

When I started bowyering my body seemed to have a stop at 40#. It still does. When a bow got to 40# every nerve said it was going to break. To fix the problem I put a 2:1 pulley system on my tree. Now my body feels 20# when the bow is at 40#. It worked. 99% of my bows are still 40# because I comfy with that but I have made a 105# warbow.
Maybe your natural stop is 35#.

[George Tsoukalas]

Do not pull to full target weight until the limbs are bending  well.

I actually don't pull to target weight until 25" for a 26" draw. But it took years to be able to do that.

Jawge

[scp]

The main thing to remember is not to pull the stave more than your draw length. I rarely pull it to the intended draw strength until the last stage of tillering. Badger has some theories about how not to cause any set by not pulling it too much too early. You probably can simply back the bow with linen or hide before you pull it fully. You will be much safer that way.

[SLIMBOB]

Why pull a bow all the way to 20 inches and 50lbs, when you can pull it to 12 inches at 35lbs and, at least in my mind, accomplish the same thing without stressing the wood as much. If at 12 inches I am at 35lbs, and I am gaining conservatively 2 lbs per inch, then I am at 65 lbs at 27 inches. I need to shed 15 lbs, so scrape where needed and then recheck the tiller. Good at 12?  Pull to 14 and check it. 35 lbs at 14 inches?  I am 11 lbs heavy. Scrape and repeat. Inching your way up to full draw length and full draw weight. I’m willing to consider that this way is less effective if some one can explain why.