Flax backing Question

[mtbow]

Hello All,
I am going to back a American Flatbow style bow with flax cordage.  Cord looks to be about 1/8" diameter more or less.  Wood is hrm.   66" NTN.  Anyway, should I cut the cord in 12" lengths much like sinew would be?   I will be using TBIII glue in preparation and as the final glue also.  I have backed a few bows with linen cloth and really like the outcome of the bows so far.  Just wanna try something new for me.  BTW the cordage was purchased at Cost Plus World Market at a very good price.  25 yards per bundle.  I think the sale price was less than $3. 

Or, should I use Knox gelatin?   I do like working with TBIII mostly.

I do believe in one of of the TBB somebody backed a bow with flax cord but didn't mention the outcome.  Might have been Tim Baker.

Thanks

Marlowe

[willie]

what is hrm?
what purpose do you want the backing to serve ?

[mtbow]

Willie HRM is hard rock maple.  I forget to mention it is a board bow.

Like most backings on white wood, to keep the grain from lifting..   

Marlowe

[willie]

marlow
is that twine a loose lay, kind of bulky sort of like knitting yarn? if so, you might consider untwisting  it and combing it straight.
lots  of voids = lots of glue.

[Mesophilic]

I was reading a while back, can't remember where or by who, on a similar subject.  I haven't done this method but ill describe as best as i can remember.   

What this gentleman said he did, strap or secure the stave back side up to a board that's longer than the stave.  Drive several nails a few inches past the limb tips on both ends.  Apply glue to the stave back.  Tie off your twine to a nail at one end of the board and the run it back and forth across the stave back from one nail to the next on the opposite side.   Repeat process until you have the desired number of strands.  Will allow you to put some tension on the twine, too. 

Hope this makes sense and gives you some ideas to work with.

[mtbow]

marlow
is that twine a loose lay, kind of bulky sort of like knitting yarn? if so, you might consider untwisting  it and combing it straight.
lots  of voids = lots of glue.

Hey Willie,  it is a twine.   I tried to unwind it and then comb it out but it comes apart.   Not like a flax strick would be.   So I sized the wood and cut pieces of the flax and soaked it in a mix of TBIII and a little bit of water and then layed in down on the bow limb.   Lot of messy work.  Left it over night.  I will apply another coat or 2 of glue to seal it more.   It will add weight though.  I will do it again on another flatbow but not sure what glue I will use.  I.E, TBIII or hide glue.   I think actually a strick of flax might be the way to go.  And then use hide glue and treat it like sinew for applying.   Actually, all said and done, linen cloth is the easiest to apply to a limb.  Pic attached of one limb. 

[hoosierf]

I’ve used hemp and flax the same way you’ve done here. I have usually put a cord wrap around the limbs out of the fades and one time on the recurve ends to hold the cord down.  I’ve done it on HHB and ash with good results when i had knots or grain runoff.  I always have used TBIII or Elmer’s Max and made the cords full length on the bow. I’ve used it on boards and staves with good results on both. I wouldn’t say it does anything for performance and on one bow i believe it cause the bow to stack rather abruptly just at full draw but overall i like it. There has been some speculation that you could get some performance gain with hide glue but i never used it for that reason.  I think i actually like linen better but i like to try all kinds of variations just see how the bows turn out.

[hoosierf]

On a side note, if you think that was messy, you should try raw flax roving. OMG its nearly impossible to get that stuff to lay flat...sticks to your fingers like, well glue....

[willie]

Marlow
if it just fell apart into short strands, I just gotta wonder if putting that much twine on with TB3 is getting you all that much protection compared to the weight you are adding. I have a hickory board bow that I backed with linen cloth and tbb3. It looks nice, shoots just ok and has not broken, but I do not know if it would have broken without the backing, or whether it would be a better shooter without it either.
I have played around with some other high strength backings for composite designs, and came to the conclusion that less is better. I have also used maple as a backing, and wish I had access to some nice hard maple for trying in a trapped back. 

[DC]

Marc has some in his woodpile