Bouncing an idea off your collective heads...

[Onebowonder]

All,

I have a few pieces of pipe straight ERC, but they are only about 2 1/2 to 3 inched in diameter.  Very few knots, but there are some.  I've sawn the round wood in half on the band-saw.  I'm wondering about making the flat middle of the wood into the back of the bow, ...kinda like a backwards bow.  I'm thinking to either bamboo back it or sinew back it.  Since ERC is most comfortable in compression, I thought this might improve the possibility of the bow tillering out well.

What do y'all think?  I've never tried a backwards bow except for green wood survival bows.  They don't last very long.  Would the idea be likely to work or more likely to blow up in my hands?

OneBow

[Pat B]

ERC, like other junipers has sapwood that is good in tension and heartwood that is good in compression. I would think that by adding a boo baking so the sapwood is the compression side the boo might overpower the belly. This is just a guess on my part. If you have enough heartwood, boo backing might work for that.

[gutpile]

ERC has go compression but the sapwood tension is not that good at all...thats why it needs to be backed

[sleek]

Id like to see that done Eric, but first chase a ring on the belly below the sapwood. Then do tje bow pyramid style and tiller it to look like a good elyptical bow would resemble, but tiller it from the side that will get the bamboo. Get it bending to the point it looks like it would be a 20 pound bow, then glue on the bamboo backing. That will bump the weight up perfectly to a heavy weight bow. If you tiller the bamboo out to perfextly match the tiller of the erc, you shouldnt have to do anything but mayne a touch of side tiller to bring it around into shape. And if its too heavy, aggressive rounding of the corners will drop it down.

Matter of fact, if its the bit of cedar i think you have, I will try that myself with my half.

[sleek]

Funny thought. If it develops set, just turn the bow bacwards and shoot it the other way. It would be an erc back boo bow. Then flip it again when it gets set that direction and make it a boo back erc.

[Onebowonder]

I don't think I had an appreciation for the idea that ERC sap wood was more tension strong than the heart wood.  Those few I've made have always failed in tension so I assumed the whole species was weak in tension.  I keep coming back to it because the stuff is so light and so pretty, but it continues to frustrate me.  Also, it's fairly plentiful around here.

Sleek - This question is in reference to the one I dried and sawed in half that you cut in Oklahoma.  It has a REAL HIGH ring count for such a small stave.  I don't know about the flipping it around idea.      It seems the tension side and the compression side could not readily be swapped without destroying the bow.  ...but I suspect you might have been joking a bit. 

OneBow

[Urufu_Shinjiro]

If you're going to back it anyway wouldn't it be worth considering taking both pieces and flattening both side and laminate them together, kind of an ERC-ERC-Boo trilam? I'm no bowyer just read a lot on this site and I'm mostly just thinking out loud.

[sleek]

Eric, i cant recall the ring count, can we get a pic? And, i was only joking about shooting the bow in reverse, a little.... I have done that before.

[Onebowonder]

Here's a pic of it's cross section.  I count right about 50 rings more or less and the radius is well under 2 inches, so for ERC, this seems kind of HIGH to me.  I don't know that it mean very much for ERC to have a high ring count.  I'm given to understand that it matters somewhat with yew and some other slow growth woods, but not sure it does with ERC, which generally grows like a WEED!  I'm sure it means that this tree is nigh as old as I am though.   

OneBow

[PEARL DRUMS]

Eric often times woods break in tension because the compression is so weak the back takes all it can until it goes ka-pow. Frets will usually happen first, but not always. Excessive set is another indicator. Of course you can add about 2500 variables to all that.

[Pat B]

A few years ago a guy brought an all sapwood ERC ELB style bow to my camp-o-rama. I was very surprised how snappy that bow was and it had very little set. I think it was 45# or so.

[BowEd]

No matter what I think a bit of decrowning might be involved from a small diameter stave as this.Belly or back.

[sleek]

I thought it had more heartwood than that. Still, your idea would work. Just whatever you do, maximize the heartwood in the belly regardless of orientation.

[loon]

why not leave the crown if it's weak in tension? it"d be like a natural "trapped" back no?

[sleek]

Loon, you got that backwards. If its strong in tension a crown is ok. If you crown a tension weak wood you increase strain on it.