Primitive Archer

Main Discussion Area => Bows => Topic started by: Yellowstave on January 01, 2020, 07:08:32 pm

Title: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: Yellowstave on January 01, 2020, 07:08:32 pm

Has anyone done a bend test on ammonia fumed wood vs untreated wood from the same piece?

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: Jim Davis on January 01, 2020, 08:09:22 pm

Doubt that anyone has done that test. You might contact the Forest Products Laboratories. They have done  some testing  of the effect of modifications to wood.

But, you could easily do practical  test. Anchor on end of a slat and  see how far it bends under a particular weight from which  it returns to its unweighted position when  the weight is removed. Fume the slat and see if there  is any change in the bend with the same weight.

Hard to imagine there would be much difference.

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: Del the cat on January 02, 2020, 03:30:16 am

First rule of writing... acronyms should be written in full where they first appear.  :'(
Del

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: Yellowstave on January 02, 2020, 05:20:37 am

Sorry I'm not a writer. I figured if someone one here didn't know what modulus of elasticity and modulus of rupture was than they probably couldnt answer the question anyway. Again my bad.

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: leonwood on January 02, 2020, 05:48:32 am

I have not done any specific bend tests but I have fumed a lot of bows and have never noticed any difference in performance, amount of set or draw weight before or after fuming

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: Yellowstave on January 02, 2020, 07:30:23 am

I think it would be interesting to see with a controlled experiment. I'm very curious about it. I have however noticed that if I have a bow thats taking set and I apply wood hardener to the belly then the set is reduced by a substantial amount. That is one reason that I started to wonder about this. Thank you all. I will get some 30 percent ammonia and try this in the near future. I plan on fuming for 10 days or so.

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: PatM on January 02, 2020, 08:39:23 am

 Pretty easy to find tests done on this.  The ammonia treatment is likely a bit different from a home done version.
 
    ht tps://scielo.conicyt.cl/pdf/maderas/v15n3/aop2913.pdf

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: Yellowstave on January 02, 2020, 09:32:48 am

I'm not most savvy researcher I know, but I have looked at all I know to look at and cant hardly find anything on a definitive test. That's why I pose the question here. I figure that there is no better spot in the world than right here to pick experienced bowyers minds. Thanks again for thoughts.

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: PatM on January 02, 2020, 10:09:26 am

The test linked to shows negligible effect in Oak sapwood and a fairly significant increase in Heartwood.

 In typical bow woods using heartwood it tends to be stronger and more elastic anyway.

 Quite a few guys have treated wood with ammonia so they could tell you if it seems to make a difference worth doing for more than re-shaping and adding color.

Title: Re: Does ammonia fuming raise the M.O.E. or. M.O.R. ?
Post by: DC on January 02, 2020, 10:19:58 am

I've fumed a couple of bows and never noticed any difference once the wood has dried. I have read that ammonia is mixed with the steam water to limber up wood that is being steamed.