Primitive Archer

Main Discussion Area => Bows => Topic started by: KenH on May 14, 2015, 11:36:15 am

Title: Flax backing re-visited
Post by: KenH on May 14, 2015, 11:36:15 am
There have been several previous discussions on flax backing bows.  But all of those discussions dealt with straight bows or at most mildly reflexed designs. 

Has anyone flax-backed a seriously reflexed design like the Akkadian gull-wing design below? 

(http://i21.photobucket.com/albums/b282/kenhulme/Akkadian_zpsd0e13781.jpg)
Title: Re: Flax backing re-visited
Post by: Onebowonder on May 14, 2015, 12:37:27 pm
Never have tried FLAX backing - but I'm curious and will be watching the thread, pardon the pun. 

...which makes me ask, when doing a FLAX backing, do you use Flax fibers, thread, or fabric in an adhesive matrix?

OneBow
Title: Re: Flax backing re-visited
Post by: KenH on May 14, 2015, 12:58:10 pm
Combed flax fiber, not twisted thread or woven linen.  At least in flat-ish bows it can add 10-15% to the draw weight.
Title: Re: Flax backing re-visited
Post by: Tuomo on May 15, 2015, 01:53:33 am
I have made some flax fiber backed bows. It is very good backing material in straight bows but not suitable for radical designs in my opinion. Remember, flax is stretching only about 1-1.5 % - a bit more than wood at best. I have broken a few flax backed bows, which were bending too much – I just wanted to test what flax can tolerate. But I think you should try!

Flax fiber backing can add quite much draw weight. I made a test: I had white oak bow, 36# @ 28” and I glued 30 gram flax fibers with hide glue. After drying the bow was 53# @ 28” – that was almost 50 % increase in draw weight.
Title: Re: Flax backing re-visited
Post by: KenH on May 15, 2015, 09:44:34 am
Would you use hide glue?  Or TBII?   Why?
Title: Re: Flax backing re-visited
Post by: Tuomo on May 15, 2015, 02:39:04 pm
You should use absolute hide glue, or any other animal glue. Glue flax just like sinew - make about ten bundles, comb them, soak in glue and put in the back of the bow. I tried TBIII but it did not work. Hide glue was very easy option.
Title: Re: Flax backing re-visited
Post by: paco664 on May 16, 2015, 12:52:49 am
where is a good place to get the flax fibers like you guys are using?

i found some yarn made of ramie/bamboo/flax and used it to back a board bow that lifted a tiny splinter... used tb2... let dry for a week and a half and then tried my darndest to break it....


i couldn't...
Title: Re: Flax backing re-visited
Post by: Tuomo on May 16, 2015, 01:37:33 am
I am using plumbers hemp - easy to get almost everywhere and usually very good quality for bow backing.
Title: Re: Flax backing re-visited
Post by: paco664 on May 16, 2015, 06:25:47 am
I am using plumbers hemp - easy to get almost everywhere and usually very good quality for bow backing.
thank you kindly!!
Title: Re: Flax backing re-visited
Post by: PatM on May 16, 2015, 08:00:37 am
I don't think plumbers in North America use the same stuff as plumbers in Europe.
Title: Re: Flax backing re-visited
Post by: KenH on May 16, 2015, 09:39:01 am
I purchased flax "stricks" from an online shop selling all sorts of knitting/weaving supplies.  Do a search on "Flax Strick"...
Title: Re: Flax backing re-visited
Post by: mikekeswick on May 17, 2015, 02:56:55 am
Remember that flax is very resistant to stretch and will therefore put quite a load on the belly.
Title: Re: Flax backing re-visited
Post by: KenH on May 18, 2015, 09:07:59 am
That's what's got me 'worried', Mike.  With that much curve I'm afraid more than just a little flax will overpower things.  I'm thinking to flax the set-back handle area out to the start of the 'shoulder' curves, and let the outer limbs alone.  I'm going to start with just a thin layer and see what happens before thinking about adding a second layer.