HIGH HUMIDITY AND SINEW

[Blacktail]

I have been told that you cant hunt with bows that are sinew back in areas of the world with high humidity..that the humidity will soften the glue or sinew...IS THIS TRUE...if i remember right i think jay Massey lived in alaska and i think he hunted with sinew backed bows..if this is right...if this is true and if a person still wants to hunt with a sinew backed bow what would be some of the ways to keep this from happening or to keep the moister out.john

[sonny]

simply for reference I'll tell you that hide glue feels tacky when the humidity is high; however I can't imagine that humidity could ever cause hide glue/sinew  to pull free from a bow back.
Jay Massey covered the sinew on at least one of his bows with rawhide, with a finish over that....I'd have to dig up the article to tell you what finish he used, but it was either epoxy thinned with acetone or [Jay] Massey's french polish (at least I think that's what he called it) consisting of shellac and tung oil (pretty sure that's right.)
 
   

[JustAim]

Cover the sinew if your worried about humidity and moisture. The traditional composite horn bows all have sinew on the back and most are covered with rawhide or birchbark etc. to help keep the moisture out. lf it works for those high performance bows it will work for anything.

[George Tsoukalas]

They get summer rain in Alaska but I'm not sure I'd consider it a high humidity environment. You want humidity? LOL. Spend a July in FL, MO or Alabama. Now don't get upset. I only mention those states because I spent some summer time there. Jawge

[JW_Halverson]

Posted this question to a friend of mine that handled a number of Jay's bows before his untimely death and he states that Jay used the two part epoxy and acetone finish on most of the bows.  He states some were covered with snakeskins and then the epoxy finish.  Here in South Dakota we use the snakeskins over the sinew and they are excellent vapor barriers even without the final epoxy coating.  

[Blacktail]

wow,this is some great info here...i will have to print this one out...o.k. what about sinew and rubbing on bees wax or sinew,rawhide and then bees wax...john

[bigcountry]

I have shot a few sinewed bows, and can tell ya, in the middle of winter when humidity is down to 30% or less outside, you got yourself a real rocket launcher.  But in those August 80-90% humid months, it turns to a wet noodle.  Espeically after a rain and its all foggy.  And both these were sealed  with snake skins and poly.

[Pat B]

You can hunt with a sinew backed bow in a humid area but the bow will loose weight over an extended period of time. No matter what you seal it with, moisture in the form of humidity will enter the hygroscopic materials like wood, hide glue and sinew.
  I have built two sinew backed bow as examples, one is a copy of the Jay Massey Medicine Bow; sinew backed hickory with a rawhide backing. I sealed this bow with Massey finish, Tru-Oil and spray poly.  When I built it I believe it was around 55#@28". A month later(summer) it was down to 45#@28" At some point in it's career it went to Colorado for a while where the weight raised to over 65#@28".
  Bow number 2 was Elkie. She is sinew backed osage with timber rattler skin covering. Also finished with Massey finish, Tru-Oil and spray poly. Again when built she was 56#@26". A month later(summer) she was down to 45#@26". I mailed her out to Colorado two weeks before a hunt and when I got there she was back up to 55#@26". After the hunt I left Elkie with Kenneth and before long the weight was back up to over 65#@28'.
  Keep your bow dry and add a coat or two of good paste wax on a regular basis and place it in the sun when possible(unbraced) and you can reduce the effects of humidity on a sinew backed bow. A selfbow isn't as susceptible to moisture intake as a sinew backed bows but extended periods in humid climate will soften it up also.

[JW_Halverson]

I shoot a sinew backed osage bow, 52" nock to nock, draws 50# at 26 inches at 40 degrees F.  At 72 degrees F then I am down to 45 lbs.   We have very little problem with humidity in western South Dakota, but warmer temps will also suck the tnap outa your sinew backed shooters. 

Have shopped for a fridge to store the bow in more than once, but I'd have to run outside and shoot awful fast before it warmed up!

Instead I compensate by putting heavier field points on the arrows to make the spine act a little lighter, or get used to the arrows coming out a little "nock right".

If you gotta deal with the humidity issue, maybe look for a small dehumidifier to put in a closet along with the bow.