Linen-backed red oak break test --WARNING GRAPHIC CONTENT!

[WillS]

Surely the only way to say that this test was conclusive is to run it again using an identical bow (including a splinter the same size in the same place) without the linen backing.

Otherwise there's no way of knowing whether the linen did anything at all, or if the wood just gave up when it wanted to give up. 

[mikekeswick]

If it was suppling a degree of safety how come the splinter lifted under it? Do you get where i'm coming from?
Is a bow that has splinters lifting on the back really a bow? Like I said I only like to do things to the best of my ability and I don't see a linen/silk/woven fabric as a truely safe way of backing a belly wood that isn't good enough to become a selfbow.
The 'primitives' would have used the best materials available just like any craftsman would. They knew what they were doing and certainly wouldn't have used substandard materials for a bow. A bow takes a lot of time and effort to make with stone tools - prime material to start with would have been the aim. If you gave a 'primitive' man a slightly dodgy grained board and some linen and a split stave i'm pretty sure I know which he would chose. We however have the ability to go and buy boards....fair enough...seems like a quick and easy way to make a bow...but (and it's a big but  ) you had better know what to look for and understand the principles of how a backing works to be able to make durable, safe bows from boards.

Hey don't get me wrong I totally respect you for doing the test. Testing things to destruction is how i've learnt a lot of what I know about bows....and it's just plain fun 

[vinemaplebows]

Would it not be easier to use bookmatched wood to get a rough idea one backed the other not?

[bayouridgerunner]

When the quality of the backing is in question, should the selection of glue be given greater consideration?

[k-hat]

Interesting post.  I think there are points on both sides to this.  A cloth backing does add a measure of protection and this ought to clearly show that.  36" in a splintered back!  Still, better backings available than cloth.  Kind of goes without saying as far as I am concerned, as there is better wood available than Red Oak...but if RO is what you got, RO is what you use.  Ditto cloth backing.  Testament to ones skills to make a weapon from less than perfect material.  I think it shows the range of ones skills.  Why make a bow out of ERC?  Because you can.

That's all I'm trying to get across Slimbob.  If you don't have access to prime materials, you do the best you can with the best of what you have.  To tell a new bowyer he's gotta use hickory cause linen is useless (besides being an erroneous opinion) is deflating and discouraging.  When i started this a cheap lowe's board and linen from the thrift store ($1) WAS ALL I COULD AFFORD!!  And i busted my but with nearly primitive hand tools to make this into a bow.  Nothing i read at the time mentioned radial grain.  When i came across the board in my early days it fit all the best descriptions (per longitudinal grain).  I didn't even know what radial grain was at the time.  So the advice to back a bow with "SOME MEASURE OF PROTECTION" is GOOD advice, as is seen here.  It made up for my lack of knowledge at the time.  Did i want a hick backing?  YES, but couldn't afford it at the time.

Will, have you ever known a bow (without interlocking grain like hickory and some whitewoods have) to hold together even to full draw (much less overdrawn) when it already has erupted multiple splinters down the back?  I haven't, but my experience isn't everyone else's.  We act like a splinter is the death of a bow, then say well who knows if it would've held on?

[George Tsoukalas]

Interesting experiment, Khat.

If you look at the left limb the tiller is about as good as it can be. However, the right limb is bending too much right where it broke which is probably why it pulled up a splinter.

For me, because I am so fussy about board choice, the purpose of a cloth backing is to add insurance to a slightly less than perfect board. I allow 2 run offs per limb ... tops. If the board has more than that it gets eft in the store. I walk away.

I don;t know have many run offs the board had.

Jawge

[k-hat]

There were multiple splinters up and down both limbs as i recall (well, the outlines of them under the backing anyway).  There was no splinter on the edge however where the break started before i overdrew it. 

As for the grain, the longitudinal grain (the edges of the growth rings) was nicely parallel on back and sides.  I don't recall it having any runoffs in that regard.  Again the radial grain was about 20-30 degrees out of parallel, which i believe is what allowed the break.

[Pat B]

That side grain or radial grain is something George has been preaching about for years but nobody seems to get what he's saying until their bow breaks along its radial grain. 

[k-hat]

yeah Pat I think that's where i first read about it was on Jawge's site.  Course that was after i had made this bow.  Been much more careful about my board selection since

[Josh B]

Man...I knew the explosion was coming and I still ducked and covered as if pieces were gonna fly out of the screen at me!  I'm sorry about the sacrifice, but I'm satisfied that the backing provided considerable protection.  How much stuff got broke by shrapnel?  Josh

[bushboy]

Not to deviated to much,I think that a less than perfect board can make adurable bow if made long and wide enough in the mid 40's range.been shooting this r/o for years

[k-hat]

Agreed bushboy

Gun Doc:  Ya you could tell i jumped a bit when it happened.  A couple things got knocked over but no biggie   Don't look too hard so you don't see my mess of a work table 

[bubbles]

The Side grain in a board almost seems more important than longitudinal grain - as the side (radial) grain is under more direct stress when bow is being bent, or so it seems to me.   Bushboy - how does the side grain look on that board of yours? There is lots of grain run-off from left to right as we can see, but is there much grain run-off from back to belly?

[bushboy]

Not to misinform and endorse boards with bad grain orenitation and I hope it didn't come across like that!being said I have had failures with much better stock! I always take the time to go through as many choices as presented!I like to experiment and am no stranger to failures.I kinda regret posting the pics I have as not to give people a false sense of sercurity!the only point I wanted to stress was with decent tiller and design durable bows can be made.this bow is 65"ttt ,2"@ the fade pyramid ,mid 40's#

[k-hat]

I think the key for you're bow bushboy is that you chose a pyramid design.  IMO that is a smart choice for a board like that if you're gonna make it into a bow.  A pyramid board bow has runoff no matter what, but it seems the strain is more evenly distributed making it less likely to splinter.  This would not be true with a parallel limbed bow using the same board.