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Main Boards => The Bowyer's Bench => Topic started by: bigcountry on January 20, 2010, 11:39:00 AM
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Last IPE/Boo bow I built, I barrel tapered the boo from 1/8" in the middle down to 1/6" at the tips. It was pretty flat bamboo, so I then glued it on my IPE and sanded off the sides of the bamboo to the glue line. So basically the bamboo was not knife edged.
I then trapped the bow making a trapazoid cutting more into the boo. I started having issues at the nodes on the edges where I was pulling up splinters. So I had to wrap with silk and sinew.
So I thought it might have been where cut into the boo trapping the bow exposing the power fibers.
So next bow, I thought I would knife edge the boo to a shape I want, then make a ledge on the IPE to trap. In other words, when I trap the limbs, I won't be cutting into the bamboo. Just trap up to the glue line. But the bamboo might get aweful thinned knife edging.
Anyone else knife edge? I read Dean Torges manual on this and he is creating a 60 degree bevel cutting into the bamboo to the glue line on his BBO bows. And he doesn't seem to have problemw with the power fibers lifting.
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When you trapped and cut more into the boo what method did you use. :confused:
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Not sure what you mean? I marked a line on the back (boo) 1/8" or less in, and used a scraper to get to that line without moving the bottom of the belly.
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I was wondering wheather you used a scraper, rasp, sanded or what. I have raised some splinters with a rasp but had better results sanding, haven't used the scraper so probably no help to you.
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It wasn't really raising a splinter yet. Just the more I tillered it, I could rub my hand up and down the side and feel it getting rougher. I even sanded it down with 1000-1200 grit to make it mirror smooth. So I just took precautions and wrapped the nodes.
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Just curious, when you were scraping was it just getting rough at the node? :confused:
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Did you knock down the node a little? (Without flattening it)
BTW I don't knife edge the boo. I just measure the tickness at the handle (1/8") and taper to the tips (1/16"). The thickness is measured from the center of the crown, to the flat surface. I initially rasp the trap cross section close to where I want it,(after cutting the glue-up to the outline of the boo) then finish up with finer tools and sandpaper.
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Originally posted by fixer:
Just curious, when you were scraping was it just getting rough at the node? :confused:
Nope, only started getting rough on the edges where you can see the power fibers while tillering. More I tillered, the rougher it got.
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Originally posted by Tom Leemans:
Did you knock down the node a little? (Without flattening it)
BTW I don't knife edge the boo. I just measure the tickness at the handle (1/8") and taper to the tips (1/16"). The thickness is measured from the center of the crown, to the flat surface. I initially rasp the trap cross section close to where I want it,(after cutting the glue-up to the outline of the boo) then finish up with finer tools and sandpaper.
So your saying you trap the core first then glue it up?
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bigcountry-
No, I don't trap anything first. The slat is still a rectangle during glue up, then cut to the outline of the boo afterwards. Do you have a copy of Dean's video? I watched that thing half a dozen times before starting my first BBO years ago.
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Originally posted by Tom Leemans:
bigcountry-
Do you have a copy of Dean's video? I watched that thing half a dozen times before starting my first BBO years ago.
Yea, I got it, and watched it, but it doesn't really address this issue. In fact, he cuts into the boo himself when he makes the facets between the core and boo.
I actually called him the other day and he said he have not had issues at the nodes, but has in between two nodes which surprised me.