Question about ERC

Flem · July 27, 2019, 02:21:00 PM

I have a nice piece of Eastern Red Cedar that I sliced up for lams. I am wondering if those of you who have made laminated Bow's with the stuff had to adjust stack thickness? It's pretty soft and lite, but I have seen where folks have made nice looking Bow's with the stuff.

Crooked Stic · July 27, 2019, 02:43:25 PM

Never used it but I would think veneers would be the way to go.

Roy from Pa · July 27, 2019, 02:46:39 PM

Yes make the stack a little bit thicker and or wider..

Crooked Stic · July 27, 2019, 04:18:43 PM

Well I guess it depends on glass or wood.

Roy from Pa · July 27, 2019, 04:25:25 PM

Brilliant sticky-pops:)

Flem · July 27, 2019, 07:47:39 PM

It's going in a ASL. I'm pretty much stuck on them. So it's going to be a glass sandwich. Guess I'll have to experiment as to how much thicker. Could be a fat mother! Was thinking about working up an equation with a known wood's properties as a baseline and adjusting for the ERC. Have no idea if that's a good idea or not?

Crooked Stic · July 27, 2019, 09:46:14 PM

I would not even think cedar would be strong enough for care. But as I said never used it before.
Tanks Roy I am briiiant at times.

Mad Max · July 27, 2019, 10:04:35 PM

Quote from: Flem on July 27, 2019, 07:47:39 PM
It's going in a ASL. I'm pretty much stuck on them. So it's going to be a glass sandwich. Guess I'll have to experiment as to how much thicker. Could be a fat mother! Was thinking about working up an equation with a known wood's properties as a baseline and adjusting for the ERC. Have no idea if that's a good idea or not?

Flem Flam what are you talking about, you posted this earlier

I've got a book I would like to pass along to someone who could use it. The only catch is you have to be nuts enough to want to build an ASL type Bow

If you like boring, inefficient Bow's, you might glean some useful info from this book. If you are currently torturing yourself building ASL's, you might not learn anything new.
I found it good for bathroom reading(clean hands only!)
If you would like it, P.M. me your address and I will send it along

Flem · July 27, 2019, 11:32:31 PM

Thats called sarcasm. My attempt at humor. I only make Hill style Bow's.

limbshaker · July 28, 2019, 06:30:05 PM

I have a Dave Johnson ASL, and he uses ERC cores exclusively. I've got a few very popular brand ASL bows with yew, bamboo, and elm cores as well.

The Johnson is fast, and light as a feather. It's noticeably lighter weight than all the rest. And also has the least handshock.

I don't make bows, but I believe ERC makes a very good bow limb when done right. I'm beyond impressed with this bow.

I believe Steve Graf prefers it as well at the time of writing his book. Which is a great read by the way.

Flem · July 28, 2019, 07:20:14 PM

Hey Chase, you own some calipers by chance?

limbshaker · July 28, 2019, 08:37:54 PM

I do. I suppose you want measurements huh?

I'll be away from home till tomorrow evening. PM me a phone number or email and I'll help however.

BMorv · July 29, 2019, 10:49:05 PM

Flem, I do this a lot with tri lams. I use either the specific gravity or the stiffness as a comparison to a known thickness. I think it's stiffness(bending resistance or MOE) is the best for comparing core type material.
Just take a ratio of the known material MOE to ERC's MOE and multiply that ratio times the known thickness. It won't be exact but will give you a good place to start.
PM me if this doesn't make sense.

Roy from Pa · July 29, 2019, 11:28:50 PM

I've used erc as a core material in a trilam.

I made the bow about 1/4" wider than if I were using red elm for a core lam.

And made the lam about 1/32nd thicker.

Now don't go expecting to make 60 pound bows with erc..

Flem · July 29, 2019, 11:43:42 PM

Cool! Thanks you guy's! How did you like the ERC as a core, Roy?
Ben, that's kind of what I was thinking of doing. I was not sure about using the MOE or the modulus of rupture. Thanks for the voice of experience.
I also need to thank Chase (limbshaker), what a nice guy! He took measurements and photos of a beautiful Dave Johnson ASL he owns and sent them to me. I think the biggest problem I'm going to have is sealing the wonderful aroma of the Cedar away where I can't get a sniff at it.

Roy from Pa · July 30, 2019, 12:00:21 PM

It's pretty, smells good, light weight, and fast.

canopyboy · July 30, 2019, 12:56:44 PM

Flem, make sure you report back how it comes out.

I found out that yew usually ends up being about 10% lower draw weight than cores with walnut, black locust, bamboo, and maple (which all seem to be about the same) in my ASLs. That said, the yew bows have been my favorite with the least hand shock. I would think ERC would be similar.

-Dave

Flem · August 01, 2019, 02:23:29 PM

Though I would solicit opinions from you guy's on color combos. I know what I like, but I've been told my taste is questionable. I'm not ready to put this Bow together, but I laid up some glass to play with. The light color one is actually close to Ivory, not white.
[attachment=1][attachment=2][attachment=3][attachment=4]

Flem · August 01, 2019, 02:25:45 PM

Forgot one
[attachment=1]

Roy from Pa · August 01, 2019, 07:18:46 PM

First one.

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