[Archers] Old Bows Cracking

[Garth Groff]

Noble Friends of the Bow,

While looking for "you-finish" bows I ran across this web page: 
http://www.ebay.com/gds/Care-of-Vintage-Recure-Bows-and-evaluating-an-old-bow-/10000000177347125/g.html 
. There is a lot of sound advice here, but one paragraph about cracks 
especially caught my attention, and I thought I would throw it out for 
general discussion.

"Often an old recurve bow will have small cracks or crazing in the 
finish. These little cracks might be in the handle area or on the limbs 
especially where the limbs bend the most- the "working part" of the 
limb- they run across the limb not in line with the limb. Usually these 
type cracks are not really a problem other than cosmetic- they are 
simply small fractures in the clear coat finish and not into the limb 
itself. Similarly some bows, especially very short bows, might have 
"stress lines" which can be in the handle grip area but usually in the 
limbs near the handle and they run in line with the limbs. Stress lines 
or stress cracks can go deeper but they also don't usually cause a 
problem except  cosmetically. Cracks in the tips of a bow or within the 
edge or laminations of a limb are a different matter and can be a sign 
of a bow ready to break. Any deeper crack running or starting to run 
across a limb is a warning of near future failure and probably that bow 
should not be strung."

I have seen these fine parallel horizontal cracks across the limbs and 
just above or below the grips and thought they were an underlying 
defect. I retired my old Ben Pearson recurve because of a system of 
cracks like this. This author claims they are surface cracks in the 
finish. Comments?

The longitudinal cracks, what he calls "stress cracks", are quite common 
on old bows. I have watched them carefully on a couple of bows, but 
couldn't see any movement or growth, and they passed the "pinch test". I 
generally regarded these as shrinkage cracks. Fiberglass is always 
changing with age, and actually remains fluid for years, just like 
paint. His observation here is a relief and a vindication. OTOH, I have 
seen longitudinal cracks that have grown as the bow was used. A few 
years ago I spotted one on a new bow in someone's loaner kit that grew 
about 1/4" in one day of use. Comments.

His observations about cracks in limb ends, or along limb edges are 
sound. I've always believed these were dangerous. No surprises here.

I recommend reading the full article (it only takes about five minutes). 
There is some really good stuff here. This might be a very good training 
resource for MITs.

Yours Aye,


Mungo