Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: Beanbag on February 26, 2013, 02:20:00 PM
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Would ERC be strong enough for a td riser? Did a search and came up empty. Was going to lam two 1" pieces together. Could even put a lam between them ?I have some pieces with out knots, just some nice grain. Thks Jim G
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ERC can do anything any other wood can, just needs to be thicker and or wider.
My biggest concern would be the threaded insert pulling out. You'd need one that has more coarse threads than youd normally use for hardwoods. Check McMaster_Carr or something.
I made a sinew backed ERC with a built up handle of ERC. It's cut nearly to center and has no problems. Bow is 64"ntn and pulls 55# or so.
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ERC is strong but brittle.It chips and dents easily.It would look awsome though.
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Ben, Went to McMaster, nice site. I have been using the inserts from Binghams. I think they are somewhat longer than what I saw. I'll check later. If they were epoxied in do you think it would work. I was concerned about the wood type because they don't seem to have many threads? Thks
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It might work if you use a strong I beam lamination. That might also help address the problem with the inserts pulling out.
It should look awesome if it works out.
Dave.
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Thats a good plan too ... set the inserts into the hardwood I beam (I assume were talking hardwood).
Epoxy is our friend. I think you could epoxy the inserts in I dont see why not. Probably be strong as anything.
Not to be too nuch of a stickler but I don't necessarily agree that ERC is brittle, it's actually quite flexible. Brittle means 'breaks without significant deformation' in other words breaks before bending much. ERC will fail in tension before compression in a selfbow or something, but it'll take quite alot of deformation.
As for the chipping and denting, its is ridiculously soft compared to most of the woods we use for bowmaking (wood or glass) and it definately requires more care than the hardwoods. I'd recommend a hard, hard, hard finish to protect it. I might consider doing something like an epoxy resin based coating. That'll cure as hard as a rock, and prevent those dings, and its shiny ....
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Ben, I've worked with epoxy quite a bit. My thought is to thin it with alcohol and saturate the wood with the first coat. It should suck up quite a bit. The following coats would be thickened. Might add some strength also, it would definitely harden the surface.
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Don't forget to post pictures!
Dave.
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I-beam and alot of glass, just IMHO.
As for the wood, might try soaking it in wood stabilizer. I know it will take alot of WS. Take a deep pan, fill with enough WS to totally cover the wood and allow to soak for about a week.
ERC is really soft and needs something that will firm it up.
Troy
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It will be stunning, but you don't wanna stun yourself on the head. I would I-beam and put some glass thru it too like Troy said. Hate gettin whacked!
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Troy, Not familiar with WS ?? How is erc under compression. I'm thinking maple, pheonelic,erc, band in front for tension. Will put the inserts tru that for extra hold. I think that will put a lot less stress on the erc. Cut up some pretty nice grained stuff tonight, pretty clean too. Thks
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I'm not familiar with WS, but this can't hurt. I liek where this whole thing is going though. Sounjds like it will e beautiful.
I think you;ll find ERC even untreated is more than strong enough, but will need to be kinda bulky, and alot less sleek than the hardwoods.
My concern would be mainly in the inserts and the sight window.
I think Troy has a good plan with the glass reinforcement. Kinda like Big Jim does on his bows where theres a 1/4" thick glass I beam in the riser, but its offest so you dont cut into it when you cut the shelf.
I don't think I said this but I may be the biggest fan of ERC in bows to ever walk the earth. I'm dying to see this and as we speak am working on a sinew backed ERC.
Pictures please.
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Ken, Why do I keep hitting my head against the wall??? Cause it feels good when I stop!! lol It wouldn't be the first time I'v e beaned the ole noggin. I have to try it though. Still have to work out the limbs. I've been researching on here for a bit but haven't got it all together yet Thks JG
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ERC is very strong in compression, not stiff, but will compress alot before being damaged. In other words it is very elastic under compression.
I think the maple would look really nice with the ERC, it'd be almost liek the color of the heartwood.
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Ben, I will start posting when I get things coming together. I'm going to see how much the epoxy infusion strenghtens the wood. I was thinking maybe putting it in a vacuum or pressurizing. I did a elk horn riser a couple of years ago that is still kicking, no sign of insert weakness yet. We'll see. JG
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A vacuum will make the wood absorb the stabilizer in a hurry. I've never done it, but I have seen it done. As the air is removed from the wood, the liquid rushes in to take it's place.
Dave.
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What is ERC?
God bless, Steve
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EASTERN RED CEDAR
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"WS" short abrevation for wood stabilizer.
Sorry for confusing anyone.
Troy
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There are epoxy resins, used for boat building, with wood and fiberglass, that are very fluid at room temperature, and can be thinned, with acetone or alcohool, depending on the specific resin. Those should work well for impregnating wood. For maximum strength, I think this should be done after the riser is fully shaped.
DF
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Well I got things together. It hasn't gone boom yet! Still have to put the finishing touches on it. It came in at 60" 58 @ 28 a little more than I wanted. I mis-figured the stack size with the cedar. Not very knotty wood,didn't want to chance a snap, it still might though. The riser is a bit bigger in the grip than I wanted , doesn't seem to to be flexing at all.
These are the pictures on flickr
http://www.flickr.com/photos/92672163@N02/sets/72157632952467683/
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Very nice.That is sharp!--Joe
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Looking good. Looks dark for ERC. Is it really well seasoned or is it just the finish you used? I love the look.
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That looks great! :thumbsup:
Thanks for sharing.
Dave.
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Ben, Was looking at the bow you're finishing up, pretty nice. Nice work on that riser. The erc I used was pretty well seasoned. You would be amazed at how much epoxy it absorbed. It did darken a bit, however it did stiffen it up alot. I could feel a little flex in the grip before I coated it but now it feels stable. We'll see if it stays together.
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I like the looks of that - well done.
Beanbag - since your pics are already on Flickr, it is just a matter of copying the bbcode and pasting it in your post and the pics would show up in your posts. Just passing on the info.
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Wow that one looks great! I like the grain near your limb bolts. Great Job!!!