Parallel crack in glass, OK or not?

[Kevin Lawler]

I've read that parallel (with the limbs) cracks are unsightly but not unsafe nor do they affect the performance. Please look at these giant pictures and tell me if you think the cracks in the glass of this 50# Martin Savannah are unsafe or would the lead to catastrophic failure or performance problems. I draw 27".
 http://www.stacgang.org/tradarcher/savannah1.jpg
 http://www.stacgang.org/tradarcher/savannah2.jpg

[30coupe]

They look like stress cracks to me, probably not going to cause any problems. I've shot lots of old Bear bows that had more stress lines than that in them. Yours show up more because they are in clear glass on a dark wood. They are usually more cosmetic than catastrophic.

[redant 60/65]

I'm with 30coupe stress cracks, I've seen them more on older bows, but I have good friend that shoots a newer Bear, there on the back side of the limbs, but he also draws about 31" he's not to worried.  

[Tom Leemans]

You can drizzle some thin superglue in there if you're really worried. I'd keep shooting it.

[portugeejn]

I regularly shoot old Bear bows with more stress than that.  I would keep shooting it, and if you wanted to, you could use a insulin syringe to put some thin superglue on the cracks.

RonP

[Apex Predator]

Shouldn't be a problem.

[bad arrow]

How old is your Savannah? ....Phil

[George Vernon]

Kevin,
I can't tell from the pics how 'deep' the defects are.

Sometimes the damage seen in your pictures can come from the limb finish 'crazing'.  Some of the finishes used on bows are very hard and will develop a network of small cracks over time with use.  This is especially true if the finish is not completely uniform in thickness.  Some look like spider webs.  Some show as a milky haze.  And severe ones can show cracks, expecially if the finish has thick spots.

One way to tell for sure is to polish the affected area with some 0000 steel wool and see if some or all of the defects disappear.  A few light coats of exterior grade urethane finish or paste wax can be used to protect the area you work on after using the steel wool.

If the defects remain, you've got cracked glass.  The limbs may last a long time, or they may delaminate at some point.  Keep the areas waxed or use a coating of thin super glue as others have suggested to keep the cracks closed.  If left untreated, moisture can and will get in leading to more damage.