toxophileken
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toxophileken
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Joined: 4:55 AM - Jan 15, 2006

7:37 PM - Feb 28, 2007 #21

I agree, George... Jon and I were talking about the case where a sinew backing was going to be applied...

Would cutting through a knot still be a big deal, in that instance?

I would think it would be better to be cautious, but that he wouldn't have to be quite so picky about the grain around the knot... Just guessing, though.

Ken
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toxophileken
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toxophileken
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3:12 AM - Jul 04, 2007 #22

Update -

This bow exploded two inches from full draw. At the time of the break, it was approx. 60# @27".

The break appears to be related to being overly dry.

It didn't break at a knot. The break seems to have started at a minor dent on back incurred during heat correction.

For more information, check out my slow motion buildalong.

Slomo

Ken
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mcombs
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4:05 PM - Oct 08, 2009 #23

Hey Ken I see that this thread hasn't been updated in a while, but it answered/brought up some questions that I have since i have only made a few bows and just started in March of 09. On the very first bow that I made (I will have to post pictures later) there were a few of the pin knots that you've concentrated on, not the true big knot, and I know I violated a few of them. Before I finished the bow I did add some super glue to those areas because I realized what was meant my ring violations after finishing it. It is right at 64" ntn, about 35-40# at 28" (haven't ever scaled it except on the bathroom scales and mines notorious for me or the scale not reading right) and I have shot it at quite a few corn stalk shoots with no problems so far. I don't know if at some point those violations will come back to bite me, but they haven't yet. I did have one of the bigger knots on an elm bow that I made that I left some of the rings caked around it like in drawing 10 and it eventually raised those caked layers and before I knew it the bow snapped at that point, so now I have made it a point to take those areas all the way to the proper ring and just take my time doing it. This is really cool to see because it clears up a lot of questions that I had/am learning about and I'm sure you have saved someone out there some headaches about what to do on the knotty wood.

One question I did have though and this is from my post about the crack in the Osage bow, is do you leave it a little wider even if it doesn't taper properly or do you taper it more on one side to compensate for what would make it larger and not a proper taper? I guess what I mean is when the grain runs around the knot like a river current around a rock, most of the time it doesn't reach all the way to the other side of the limb for me and if I make it a proper taper I will be cutting through the grain line on the other side to make it taper correctly. I know you have to cut through some of the grain in order for it to taper at all but I don't know what degree of "grain violation" is allowable. Maybe this is another topic all together as this has caused some confusion with me in making bows and following the true grain so it doesn't run off the sides severely. I have seen some bows where people have made bows that were straight and didn't follow the grain at all and they have claimed it hasn't ever caused a problem, which I don't understand.



So where the red dotted line is what would need to be filed/scraped off in order to follow taper.

Thanks for this post.
Last edited by mcombs on 4:38 PM - Oct 08, 2009, edited 2 times in total.
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toxophileken
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7:25 PM - Oct 12, 2009 #24

Glad it helped you Mcombs, and thanks for the kind words.

No, I wouldn't remove wood at the red line you've drawn. The idea is to both follow the lengthwise grain, and to leave more width to compensate for the knots. I add about as much width as the knots are wide. I.e., if you have 1/4" of knotty/iffy area, leave about 1/4" more width. Actually, that is what I do for punky or dead wood, so you can likely get away with less width for sound knots.

Yes, the swell in width taper goes against the idea of starting wide and running to thin. But it is necessary. I like to see the swell very gradual and smooth looking. I often see it too abrupt. Your excellent drawing shows a pretty good one, that could be a bit more smooth.

Also, some experienced bowyers advocate leaving a little more thickness at knotty areas. This will make it bend less. Personally, I haven't had too much luck with that, as it makes the areas on either side of the stiff spot tend to act weak. I'm sure if I worked on the technique, I would learn to smooth the transition of the bend there, just as I just mentioned about the width profile. I'm just not sure I care to try it that way, as the way I do it has worked well enough for myself and others.

Ken
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