Primitive Archer

Main Discussion Area => Bows => Topic started by: Hojo on July 22, 2009, 06:06:27 pm

Title: Compression Strength Ratings
Post by: Hojo on July 22, 2009, 06:06:27 pm

For making all-wood laminated / backed bows, what woods are good in compression?  Looking at Baker's list of woods from TBB4, the ratings seem to deal with strength in tension rather than compression.  It also appears that SG values fail to correlate with compression strength----Osage and Hickory, for example, are high in SG, but Osage is good in compression and Hickory is not.  Likewise, Black Cherry is lower in SG, but is spoken of as rating highly in compression.  Maybe I've got this wrong.....??

My main purpose in asking is that I've got some hickory that can be used for backing strips.  I've got some sugar maple, apple, and hackberry that could serve as belly wood, but don't know if any of these are even a good choice.  

Thanks all !
Howard

Title: Re: Compression Strength Ratings
Post by: rileyconcrete on July 22, 2009, 06:14:59 pm

Dont Know alot about Compression and tension of different woods.  but I can tell you that I have read of people using hackberry for bows.  Im new to bow building and havent worked many kinds of wood but have been told hackberry is easy to work with.  Hope this helps.

Title: Re: Compression Strength Ratings
Post by: Dauntless on July 22, 2009, 06:27:59 pm

Usually density is a good indicator of compression strength.  Silver Maple 0.47 SG will chrysal almost anywhere while Ipe 1.00+ SG usually won't.  Some woods are better in compression for their density like Cherry or Yew, some worse like Purpleheart or Black Locust (I hear).

I think any of those woods you mentioned would do fine under Hickory.  Just don't make rounded bellies.

Hickory just tends to take more set in compression, we rarely hear about it chrysalling though.

Title: Re: Compression Strength Ratings
Post by: adb on July 22, 2009, 08:25:09 pm

Yew heartwood has a relatively low SG (usually around .50), but is one of the best in compression. My favourite belly woods, in no particular order are:
yew, osage, cherry (choke & black), maple, ipe, lemonwood, ash, apple, and jatoba. My least favourite belly woods: hickory, oak, purpleheart, and walnut.

Title: Re: Compression Strength Ratings
Post by: radius on July 22, 2009, 09:17:11 pm

if it were me, i'd go with the hackberry first...it's regarded pretty highly on this forum, i think

radius

Title: Re: Compression Strength Ratings
Post by: Hillbilly on July 22, 2009, 09:49:05 pm

I would guess that all of those would work well with a hickory back if you keep the hickory thin.