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Main Boards => The Bowyer's Bench => Topic started by: Flem on July 27, 2019, 02:21:00 PM

Title: Question about ERC
Post by: Flem on 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.
Title: Re: Question about ERC
Post by: Crooked Stic on July 27, 2019, 02:43:25 PM
Never used it but I would think veneers would be the way to go.
Title: Re: Question about ERC
Post by: Roy from Pa on July 27, 2019, 02:46:39 PM
Yes make the stack a little bit thicker and or wider..

Title: Re: Question about ERC
Post by: Crooked Stic on July 27, 2019, 04:18:43 PM
Well I guess it depends on glass or wood.  :bigsmyl:
Title: Re: Question about ERC
Post by: Roy from Pa on July 27, 2019, 04:25:25 PM
Brilliant sticky-pops:)

 :thumbsup:
Title: Re: Question about ERC
Post by: 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?
Title: Re: Question about ERC
Post by: Crooked Stic on 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.  :banghead:
Title: Re: Question about ERC
Post by: Mad Max on July 27, 2019, 10:04:35 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  :dunno: :) :tongue:

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 :banghead:
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
Title: Re: Question about ERC
Post by: Flem on July 27, 2019, 11:32:31 PM
Thats called sarcasm. My attempt at humor. I only make Hill style Bow's.
Title: Re: Question about ERC
Post by: limbshaker on 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.
Title: Re: Question about ERC
Post by: Flem on July 28, 2019, 07:20:14 PM
Hey Chase, you own some calipers by chance?  :goldtooth:
Title: Re: Question about ERC
Post by: limbshaker on July 28, 2019, 08:37:54 PM
I do. I suppose you want measurements huh?  :goldtooth:

I'll be away from home till tomorrow evening. PM me a phone number or email and I'll help however.
Title: Re: Question about ERC
Post by: BMorv on 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. 
Title: Re: Question about ERC
Post by: Roy from Pa on 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..
Title: Re: Question about ERC
Post by: Flem on 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.
Title: Re: Question about ERC
Post by: Roy from Pa on July 30, 2019, 12:00:21 PM
It's pretty, smells good, light weight, and fast.
Title: Re: Question about ERC
Post by: canopyboy on 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
Title: Re: Question about ERC
Post by: Flem on 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.
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Title: Re: Question about ERC
Post by: Flem on August 01, 2019, 02:25:45 PM
Forgot one
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Title: Re: Question about ERC
Post by: Roy from Pa on August 01, 2019, 07:18:46 PM
First one.

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Title: Re: Question about ERC
Post by: Mad Max on August 01, 2019, 07:31:10 PM
Clear Glass
Title: Re: Question about ERC
Post by: Flem on August 01, 2019, 07:47:57 PM
Homey don't make no clear.
Although clear would look nice!
Title: Re: Question about ERC
Post by: Crooked Stic on August 02, 2019, 08:02:41 AM
What is the green stuff?
Title: Re: Question about ERC
Post by: Flem on August 02, 2019, 08:24:01 AM
The green is a semi translucent experiment.
Title: Re: Question about ERC
Post by: Crooked Stic on August 02, 2019, 03:49:13 PM
 :saywhat:  So if the green works you tell us about it right?
Title: Re: Question about ERC
Post by: Flem on August 02, 2019, 06:27:28 PM
:saywhat:  So if the green works you tell us about it right?
You bet! 
It will work, I just don't know if it's going to look like poo or not.
Title: Re: Question about ERC
Post by: Forwardhandle on August 03, 2019, 04:52:56 AM
I'm liking that ivory but there all nice  :thumbsup:
Title: Re: Question about ERC
Post by: Crooked Stic on August 03, 2019, 06:31:06 AM
Ha what till you see the green in the one I am about to glue up.   :scared:
Title: Re: Question about ERC
Post by: Hoosierarcher88 on August 04, 2019, 10:26:28 PM
I know ryan benoit of benoit bowcraft uses erc. Very beautiful bows and it seems to work good for him [ You are not allowed to view attachments ]
Title: Re: Question about ERC
Post by: Wolftrail on August 05, 2019, 12:07:48 AM
Sweet looking bows there 88.
Title: Re: Question about ERC
Post by: Hoosierarcher88 on August 05, 2019, 12:11:30 AM
Sweet looking bows there 88.
Ive been considering trying one just to see how the erc cores feel. I shot a pair of longbows a few weeks ago that were identical except one was boo core and the other walnut and honestly liked the feel of the walnut one better. I want to get set up to make some asl's just so i can experiment on different cores
Title: Re: Question about ERC
Post by: Crooked Stic on August 05, 2019, 05:52:04 AM
Edge grain walnut makes a good core. Just be sure to get plenty of glue on it.
Title: Re: Question about ERC
Post by: Roy from Pa on August 05, 2019, 06:42:35 AM
X's 2 on plenty of glue on the walnut.