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Main Boards => The Bowyer's Bench => Topic started by: TrenchFoot on March 08, 2025, 08:18:51 PM
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For those of you that have been waiting with baited breath, it’s almost make or break time, forms made ( a nice gentle recurve of my own design :pray: )just gotta install hardware, ovens made (collapsible, insulated, 4 200 watt lights on split parallel circuits 2 bulbs each), risers glued up (wenge, leopardwood, and Purple Heart) and ready to shape. Basically just have to splice my back lams and I’m ready to go.
1 question, do I need to trim lams and glass down to final length before glue up or trim after?
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Don’t mind the sawdust, that’s tomorrow trenchfoot’s problem
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I cut mine to length after glue up, measure from center in each direction and cut with the bandsaw.
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Be sure and hit that form really well with a couple coats of shellac or good sealer before you start cooking it in the hot box.
I'm curious what taper rates you are planning to use on that one? ....
You should post a photo of your riser all ready to plug into the form. There are enough seasoned bowyers here that might have some helpful suggestions on the best way to shape the fades, and have ideas on over all riser length too.
Also seeing the shape of your belly ramps may determine the best lam thickness for a smooth lay up and good joints.
.02 cents worth....
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Be sure and hit that form really well with a couple coats of shellac or good sealer before you start cooking it in the hot box.
I'm curious what taper rates you are planning to use on that one? ....
You should post a photo of your riser all ready to plug into the form. There are enough seasoned bowyers here that might have some helpful suggestions on the best way to shape the fades, and have ideas on over all riser length too.
Also seeing the shape of your belly ramps may determine the best lam thickness for a smooth lay up and good joints.
.02 cents worth....
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.05 clear Gordon
actionboo .075" butt - .001"
hard maple edge grain .085" butt - .001"
.04 clear Gordon
6” .035”-0” tip wedges
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Good looking belly ramp shape.... after you sand the fade tips to a feather edge you'll be golden.... When you can see light through the wood at the tips you are good to go. That last 2" should be about 1/8" to nothing. :thumbsup: :thumbsup: :thumbsup:
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Just me, but I'd go with. 04 glass front and back with two core lams that bring it to the same total stack. As is you are at 36% glass. You could also go with. 03 glass and three core lams at the same .25 stack and be at 24% glass that, at least in my estimation, would be a more efficient stack.
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Just me, but I'd go with. 04 glass front and back with two core lams that bring it to the same total stack. As is you are at 36% glass. You could also go with. 03 glass and three core lams at the same .25 stack and be at 24% glass that, at least in my estimation, would be a more efficient stack.
I agree with the .040/.040 glass being optimum, but starting will .030 glass doesn’t give you much wiggle room sanding for limb balance. Less limb stability with thinner glass too…..but looking at that form, I don’t see any issues with torsional stability that stands out. .02 cents worth.
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Enough sanding for tonight, fits the form like a glove, 3/4 done
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Beautiful fade there… you got this! :thumbsup:
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Remember youre going to be laying a .001 taper under that riser so the riser fitting to the form perfectly may leave you with a slightly thicker glue line or a gap to the form at the fades
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dbeaver has a good point there…
You may be wise to put your glass and the outside tapers into the form dry, and fit the back of the riser before lay up. With two .001 tapers on the back ,plus the glass I think your fit will need to be adjusted.
Or better yet , reconfigure your stack running a par on the back , with the taper on the belly. I don’t think you would be disappointed in using just an overall .001 FT on that design. But you could just use an .002 if that is what you want.
Next question: Are you splicing the two lams together end to end on the back side of the riser? Or running a full length lam?
Years ago I played with splicing lams prior to lay up with mixed results. Some came out good, some not so much…A lot of them came apart bending them into the form….. I finally quit splicing those and found milling full length lams for the back was much easier to deal with.
Things to think about…. Just trying to be helpful here with a little insight before you get into the thick of it with epoxy flying….. Kirk
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dbeaver has a good point there…
You may be wise to put your glass and the outside tapers into the form dry, and fit the back of the riser before lay up. With two .001 tapers on the back ,plus the glass I think your fit will need to be adjusted.
Or better yet , reconfigure your stack running a par on the back , with the taper on the belly. I don’t think you would be disappointed in using just an overall .001 FT on that design. But you could just use an .002 if that is what you want.
Next question: Are you splicing the two lams together end to end on the back side of the riser? Or running a full length lam?
Years ago I played with splicing lams prior to lay up with mixed results. Some came out good, some not so much…A lot of them came apart bending them into the form….. I finally quit splicing those and found milling full length lams for the back was much easier to deal with.
Things to think about…. Just trying to be helpful here with a little insight before you get into the thick of it with epoxy flying….. Kirk
Looks like I just need to shallow out the belly ramps a bit and I’m good, this is 40 lbs of air
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Perhaps just the photo, but looks like the space between bottom and top form is way to large. Hose is almost circle round.
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Perhaps just the photo, but looks like the space between bottom and top form is way to large. Hose is almost circle round.
It’s an inch and a half via Kenny’s guide, the riser section def is too high though hence the block
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I believe Kenny say 1.125. I use a gap of approx 3/4 inch from top of laminates with slightly less at belly ramps.
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I believe Kenny say 1.125. I use a gap of approx 3/4 inch from top of laminates with slightly less at belly ramps.
Damn… it does say that. more form work to do
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I believe Kenny say 1.125. I use a gap of approx 3/4 inch from top of laminates with slightly less at belly ramps.
Damn… it does say that. more form work to do
You can solve any forward taper fitting by putting a taper under the form top in reverse when when you build the form. Form top meaning formica or whatever you use. You can also close the gap with a lay up of whatever you can come up with to lay under the taper.
Also could convert the form to a topless and there is no need to worry about gap.
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Also could convert the form to a topless and there is no need to worry about gap.
We’re too deep for that
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I totally agree that you have too much space between your forms. I've got some of mine that have a wee bit to much gap and have belly ramps steeper than yours. So i wouldn't go flattening out those belly ramps quite yet.
What i do is insert a couple of hardwood wedges like oak or maple in the belly ramp area. I use two of them, about 3/4" to nothing about 10" long, and place one from each side on top of the hose just overlapping the wedges and sticking out the other side..... Then i bump my air pressure to about 20-30# and let it set for a few seconds. Then tap those wedges in from each side until the lams in belly ramps tighten up and come together. THEN i pressure it up to about 45# and take a good look at the glue lines... If it needs a couple more taps, i do it then, and then top off the pressure at 55-60#.
This wedge system works well on radical recurve limbs quite well too. Especially the heavy draw weight RC static tip varieties. I've actually had to use clamps to help me bend some of those 100# plus limbs into the form before getting my zip ties tightened up. That's when i started using the seriously heavy zip ties too. Std zip ties wont hold those heavy draw weight limbs in place..... Those also work great for cinching up belly ramps before putting the hose on it. Hope this helps...
https://photos.app.goo.gl/hTbPuGiVJC8F2AiY6
https://photos.app.goo.gl/FT1FuY6tU4KALVT26
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Wooooooooo! I did it! Everyone that had good advice, thank you!
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I’m not finished with it by any means but I put a string on it and it’s pulling 30-35 lbs max what’s the advice on bumping that up by 25-30 lbs? Thinking def .05 glass on the back, obviously increasing the lam thickness, but how much is the question.maybe parallel lams? Tip wedges? I’d hate shortening the limbs.
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I’m not finished with it by any mats but I put a string on it and it’s pulling 30-35 lbs max what’s the advice on bumping that up by 25-30 lbs? Thinking def .05 glass on the back, obviously increasing the lam thickness, but how much is the question.maybe parallel lams? Tip wedges? I’d hate shortening the limbs.
Sand that glass with 80 grit and put it back in the form with another layer of .040 glass. Or you could put carbon over it too. How bout a photo on the tiller tree at brace and full draw? love to see how she's bending.
Kirk
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I’m not finished with it by any mats but I put a string on it and it’s pulling 30-35 lbs max what’s the advice on bumping that up by 25-30 lbs? Thinking def .05 glass on the back, obviously increasing the lam thickness, but how much is the question.maybe parallel lams? Tip wedges? I’d hate shortening the limbs.
Sand that glass with 80 grit and put it back in the form with another layer of .040 glass. Or you could put carbon over it too. How bout a photo on the tiller tree at brace and full draw? love to see how she's bending.
Kirk
Will when I get to that point, I just threw a string on it out of curiosity compared to an OLD bear 45# I have. I’m gonna keep this one at weight and my son can use it when it’s finished. Looking forward to the next stack at this point
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Do you have the lam stack calculator spread sheet yet? If not , shoot me an email and I’ll send it to you. It’s pretty darn close . Kirk
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Do you have the lam stack calculator spread sheet yet? If not , shoot me an email and I’ll send it to you. It’s pretty darn close . Kirk
I was going off the 3rivers table
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To big of a gap and your hose will roll sliding everything out of whack .I have a dozen forms and all were made with a 5/8 inch gap .