Dyneema String

[fish]

I posted this question on OZbow campfires but everyone is reluctant to comment. Anyone here know of any reason why braid dyneema fishing line should not be used as a string material? I have about 1000m of 150lb Berkly Wiplash and would rather not buy a very similar product that is more expensive because it's marketed for another purpose. Is dyneema fishing line the same as dyneema bow string material, in a different package? There is the obvious difference of the fishing line being braided but I can't see this being much of a disadvantage. Any thoughts??

[No eye deer]

It;s possible that someone like Beaver Industries or whoever sells Dyneema (they use it for winch rope on 4wd's) might be able to tell you.

Mark

[Warlocke]

Braid won't make very good string material.

Normal Dyneema or blends are smaller fibres wrapped in bundles that, when twisted together make a single large strand.

When waxed this becomes a uniform, round string whereas the braid will always be a group of strings and not compress to the same diameter as the bowstring material.

It will work but not as well as the proper Dyneema string material.

This material will have poorer fit in the cam grooves and less adhesion to the servings.

[fish]

Warlocke,

Thanks for the info. I was thinking more for traditional bows. Is there a rule of thumb as to how strong a bowstring should be in relation to the draw weight of the bow? Possibly a mathmatical equasion (ie. draw weight X 10)?

[Warlocke]

Check out this link on string building.

http://www.lexicon.net/amron/stringmaking.htm#Step%202%20:%20Determine%20Bow%20 String%20Strand

Simple, informative and to the point information on all things to do with stringmaking.

[fish]

Warlocke,

Thanks for the link. If I use their formula

Bow weight (lbs) x 4
Strand breaking strain (lbs)

I would only need 2 strands (actually 1.6) of 150lb material to make a string for a 60lb bow. Can that be right? 2 or even 4 strands of the dyneema fishing line would be only a fraction of the diameter of my current fast flight string. I would obviously have to work out a way to build up the loops and serving to an acceptable diameter.

[Warlocke]

In the situation where you are using a material not normally designed for this purpose, I would measure the diameter of the string already on your bow, and use as many strands of the braid as it takes to match the original string.

It won't matter if it will theoretically be too strong, rather this than too weak.

Different materials are measured according to their usage, the braid would probably be measured for its longitudinal strength whereas the bow string material would be measured for its strength under distortion with load.

Just a guess, but it makes sense.