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Main Boards => The Bowyer's Bench => Topic started by: Appalachian Hillbilly on January 04, 2022, 08:47:25 AM
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Anyone laminated any strips of thin brass shim stock into any riser designs?
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Don't do it, it's been talked about before.
I can't remember why, It wont stay together
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Not yet... But I have copper laying around that I been wanting to do that with...
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You would likely have bonding issues if its subject to any dynamic stress. Better off to do inlays of metal. Thin gold colored G-10 sheet would work as would this stuff;
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I will look into the colored laminate.
I have a design that just needs a small section. I may have to scuff up a piece real well and do a trial laminate and some destructive testing.
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I have heard that acid etching metal can increase bond strength.
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If only the edges are showing you could maybe drill lots of holes in the brass so the glue can go through to both sides and adhere to the wood. Like Mark I don't think I'd try...even though I know very little about this sort of thing. :dunno:
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I knew I read about this somewhere,
https://www.smooth-on.com/page/preparation-surfaces-epoxy-adhesive-bonding/
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Thanks for that link! I need to go look at my chemicals. I know I have the ferric nitrate. Ammonium persulfate dip might be possible too. Will play with this and see what I come up with.
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Anyone laminated any strips of thin brass shim stock into any riser designs?
Depending on which brass alloy you have it will be 6-9x as stiff as our typical bow hardwoods and 2-3x as stiff as the fibreglass lams. That much differential stiffness is going to cause problems for keeping the brass glued to the wood. If you put the brass strip near the center of the riser thickness that increases your chances of it working but it may still be a problem. If you wanted to put a brass overlay on the side of the riser and again stick to the center of thickness I would guess that is much more likely to work.
Mark
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2 pieces about half inch long, center ish of riser.
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Are they solely for appearance? Do they need to go all the way through the riser, or could you inlay them? I’d love to be able to work copper into a bow; I don’t know why, but I love copper. I put that stuff on everything, table tops, chess boards, knife handles, but I didn’t think it would work in a riser. You used to be able to buy sheets of veneer with a bunch of patinas online, but they stopped doing them last year.
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Solely for appearance on a portion of an edge for an accent piece.
I am going to modify this center design using different colored woods to make an arrow in that center area. Black Wenge for the broadhead with the edges in thin brass, then maple for the shaft portion and I have some highly curly maple that I want to cut and make the waves, quilts look like fletching.
Rest of bow will be a dark wood such as walnut, or rosewood
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I for one would like to see that.
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Solely for appearance on a portion of an edge for an accent piece.
I am going to modify this center design using different colored woods to make an arrow in that center area. Black Wenge for the broadhead with the edges in thin brass, then maple for the shaft portion and I have some highly curly maple that I want to cut and make the waves, quilts look like fletching.
Rest of bow will be a dark wood such as walnut, or rosewood
Why not try inletting brass/copper wire. You could make some interesting designs that way, hammering and gluing wire into cut channels on the surface of a riser.
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My experience with adding synthetics like G10, fiberglass and so on as accents has not been satisfactory. Not because of bonding issues, but over time wood moves no matter how well sealed (excluding totally impregnated with resin) and synthetics which do not move develop “catch-edges” that can be felt by the hand if not seen by the eye. I am reasonably sure the same would happen with a brass accent added as lamination. Wire inlay as suggested would be a better idea imo.
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Onetone, do you not make fiberglass skinned bows because of the movement?
Hillbilly, I've been thinking about that brass shim stock. You could get some fiberglass fabric to match the thickness of the brass, lay brass strips near the edges and fill the empty space with the fabric. I would imagine you would still have to do the etching.
I like your plan, sounds like it will look very cool. One way or another, I bet you can make it work :thumbsup:
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I think onetone is talking about in the riser, and I've had the same deal. I would much rather use wood accent strips in the riser. Haven't noticed it on limb edges. Maybe because the wood is thicker in riser so more room for shrinkage (or swellage )
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Flem - synthetics laminated as accents in risers, with the main mass being wood, present a different situation than when using glass on belly and back of limbs with only a thin margin of edge grain of the core lams exposed to be atmosphere. In my experience I’ve not seen catch-edges developing where glass meets wood on limbs, ramps or the backs of risers, which is what I assume you mean. Whereas in risers it has happened numerous times. It has never been a structural thing progressing into cracks, but the craftsman in me finds it distracting and so I now use only wood in wood risers. This is likely more of an issue in dry climates like NM where I live and may not be a factor in other areas. It shows up a year or two after the bow is finished. :dunno:
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Thats interesting, never occurred to me, but then I've never made a composite wood/laminate riser.
That also means the wood is still shrinking and had not reached environmental equilibrium at the time of construction.
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Onetone, I have seen this as well. I have an OMP Sektor II riser that is half G10 or the likes, and half wood. It has developed the "catch edge" where the wood has shrank etc and the glass did not give. What I want to do will be a very small piece and very small area.
My Ammonium persulfate will be her tomorrow to try the etching. The wire inlay idea is also interesting as well!
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Hillbilly, That has a good chance working if it is small and brass sure looks good with any wood! It’ll be interesting to hear how your approach works.
Yeah no G10 I beams for me for the reason you mentioned. I’ve found ways to make risers strong enough using only wood.
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My experience with adding synthetics like G10, fiberglass and so on as accents has not been satisfactory. Not because of bonding issues, but over time wood moves no matter how well sealed (excluding totally impregnated with resin) and synthetics which do not move develop “catch-edges” that can be felt by the hand if not seen by the eye. I am reasonably sure the same would happen with a brass accent added as lamination. Wire inlay as suggested would be a better idea imo.
This post is spot on.... I did brass accent strips in a riser many years ago. using 36 grit paper in the drum sander was enough for bonding using EA-40. No issues at all strength wise.... BUT.... wood moves a lot, and brass doesn't move at all with moisture content changes. I had to sand that riser down several times because the brass was standing tall, and the finish cracks at the metal accent line every time.
I would highly recommend using different color hardwoods, or do a wire inlay deep enough to go over it with epoxy to mitigate finish cracking. That would be a tough inlay to pull off though.....
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I got my chemicals in the other day but with the snow storm, have not been to the shop in over a week.
I am also looking at colored epoxy inlay. Similar to wire, but fill then inlay cutout area with epoxy. Like they do fancy table tops etc.
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Any time you start mixing composites and wood in a riser you can have issues. running phenolic or even glass for accent lines will come back to haunt you when shipping bows to different climates regardless on how diligent you are keeping MC levels below 9-10 %. Wood moves brother. Good luck with your venture. love to see the finished product.