Rats! Hickory backed ERC long flatbow with longitudinal crack

[bobnewboy]

Hi All,

Well I decided to take the ERC challenge, and cheated a bit by using a hickory backing.  I made the bow long and wide to hopefully avoid problems, but it hasnt quite come out right.  The bow is 68" long, 67.5" NTN, and 1 and 7/8" at the fades, with a block of ipe to act as a handle thickener.  The bow bends well, but is stiff in the handle by design.  It also has pin nocks with a sliver of buffalo horn overlaid for reinforcement.  All was going very well, and I've test shot a load of arrows out of it - light in the hand, nice and quick shooting, and about 45-50lb at 28".

Unfortunately, after about 50 test arrows I inspected the bow and found a hairline crack running longitudinally down one side of the handle, extending into both limbs for about 3".  The crack is a little difficult to see in the photos below (I have clumsily outlined the area), and seems to have run into the wood across the grain at about 90 degrees.  The ERC is pretty much quarter sawn and quite clean really, and the hickpory back is as tough as could be hoped for.

So I'm a bit puzzled why the ERC cracked like this.  Any ideas?  Have I made a schoolboy error?  Secondly, do you think it can be saved?  The bow still shoots well, but I'd rather a big-ish splinter didnt ping off the side of the bow at full draw someday   .  Do you think that a wrapped binding around the handle and the fade areas of the limbs will be enough to save it?  I'd be glad of some advice......

[JW_Halverson]

You may be able to save it.  Try using a little of the really thin/runny superglue along the crack and then wrap your fadeouts with a binding such as sinew.  Before you start wrapping, round off the edges that you are wrapping so that there is less "focus" for the stress points to gather.  It will also make the wrapping last longer, too.  Wrapping a sharp bend weakens the wraps, and they tend to wear off more at those points, too.

Nice looking bow, too.  Good luck. 

[Pat B]

I agree with JW! 

[bobnewboy]

Hi Fellas,

Thanks JW & Pat, I was thinking along the same lines.  However, the only sinew I have at present is unprepared and fairly short at that.  Currently I'm thinking that I'll run some thin superglue in, as you said, and then wrap with some unwaxed linen or silk thread starting at the middle of the handle and outwards to fades for each limb, and soak that in more glue.  Then I'll put my usual soft brown leather (there's a heck of a lot in an old jacket!) covering over the handle area.

I'll post again when the fix is on, and I've tried a load more arrows out of the bow.  Fingers crossed!

Bob

[RyanY]

That's weird. Is it an actual crack or a compression fracture? I can't really tell from the pics, not that I could offer much help in the way of advice anyways. Hope you can save this one. Looks like a great bow.

[bubby]

go with Patb And JW, dont have much to lose, if she's gonna blow, she'll blow, Bub

[ricktrojanowski]

No harm in trying a fix, Hope it works for you.  I feel your pain.  I made a sinew backed ERC a while back.  Had it completely tillered and after the first couple of draws off the tree......BOOM .  ERC is a tricky, unpredictable wood.  Still want to try again.  Let us know how the fix works out.

[Grunt]

Quartersawn lies to you sometimes. It has to be perfectly straight on all four faces. 

[JW_Halverson]

Quartersawn lies to you sometimes. It has to be perfectly straight on all four faces. 

At first I thought you were talking about a politician!

[Little John]

Wierd that the handle would try to pop off. Hard to tell from the pics what happened. I would try wrapping the problem area with gut hafting material. Soak with water an squeeze out the excess water till the material is soft and stretchy, Set with Tite bond three for a water pruff shrink on binding. I did this once to repair a crack in a  handle fade and once to make sure a glued on hndle styed put, both still working. It makes its own handle wrap and you can make it as thick as you want it.    Kenneth

[HatchA]

Looks like a beautiful bow!  I hope you can save it...

[Scott E]

I have the same cracked area in my current project. Instead of researching before I did something I just went ahead and steamed a seasoned hickory floor tillered bow to straighten it. Well, the same type of crack showed up from checking. I have been supergluing the crack, but the more I tiller it keeps on slowly extending. I will be interested to see how the thread works. Your bow looks really nice, hope it works out.

[bobnewboy]

Thanks guys. I havent had time to do the fix yet, but I will report back.. Stay tuned 

[bobnewboy]

Hi All, well, I finally got some time to do the fix and put some arrows through the bow.

Firstly I shaped the handle for a comfy grip, and then varnished that area.  Then I made the first wraps above and below the handle area by using black silk tape soaked in superglue wrapped tight around the bow, and then varnishing over the taped section when dried.  This was how the bow was shot four times round our club's 3D course, including one open shoot. 

The bow has reasonable performance with my 500 gr arrows, but came out a little light at about 42-44lbs @28 inches.  Having said that the bow does not stack at all, and the arrows go where they are pointed really quite well, so I was happy.

All went well, but I noted that there were some marks in the varnish coat on the lower mid limb.  These more or less equated to the point where the odd runoff I originally noted would finish still within the bow.   So I decided that for my peace of mind I would also apply a black wrap to the lower limb of about a half inch wide, using up the rest of my black silk tape.  The bow looked a bit odd, so I then evened it up a bit by using some red silk tape on the upper limb, in the same placement as the lower limb but his time for decoration only.  I have also piked the bow down by an inch or maybe an inch and a half and reformed the pin nocks.  The pin nocks have a sliver of buffalo horn as an overlay, because the wood (even with the hickory backing) is a little soft and I like the extra security.

The bow is now 64.5 inches NTN when strung, and about 67.5" long overall.  The limbs are 1 and 7/8" at the fades, tapering evenly along their length to 0.5" wide at the pin nocks.  The string is three skeins of three threads of 452X, two skeins of yellow, one of black.

I will find out how it shoots now at a 3D shoot run by another club this Sunday.  Some pics to follow.

[bobnewboy]

I should have said that I still have to add a piece of old jacket sleeve as a handle covering, and the finish is Ronseal floor varnish (cheap and waterproof).  Here are the pics....The full draw one appears odd because I straightened the horizon along the arrow