Black Glass???

[Vamp]

Has anyone had any issues with black glass splitting long ways on a limb that was just laminated. This has never happened to me before and I did everything the same as I always have.

Is it dangerous and should I toss them?

[Vamp]

This is a R/D longbow using the heat strips and the pressure is 60psi in the hose

[Robertfishes]

what wood is under the glass?

[Vamp]

Bamboo

[kennym]

I've seen one bow that did that , with clear ul glass, I think.  It did it months later, and I figured it was maybe the lams were too dry when laid up and collected moisture later. Not sure.

Yours obviously didn't have time to do that anyway.

Can you check the heat strips to see if they are running too hot? Just thinkin....

[Vamp]

The heat strips were running at 160 degrees and were under a metal strip..

[kennym]

I guessed they were good, but just tryin to figure a reason...

I guess you had a metal pressure strip under the air hose also?

[Randy Morin]

Maybe your hose is too round...applying too much pressure in the center of the glue up.  Just a thought.  Maybe your bamboo if it was lamboo split at one of the lam lines and created a gap under your glass.

Hard sayin...not knowin.  

[Vamp]

Crap... This is killing me. Never seen this before. Thank you for all of your help. I guess Im gonna have to start over. UUUGGGGG!

[johnny girardi]

ACTION BOO can take on moisture Im not sure if thats it but it can crack ul glass.I have seen to much smooth on crack veneers with hydraulic when air is applied.This may crack glass. maybe a little less glue.

[Vamp]

I did what Ive always done while building. There was nothing different I did except for using the black glass. I called Bingham and they told me to send it to them. So I packed them up and sent it out today.
Both sided of each limb had the same thing happen. Extremely strange, Even the guy at bingham said he never heard of such a thing in the 30 years of building. So I guess we will see what they say. They are awesome there. All about customer service.

[7 Lakes]

Did it crack along the edges or down the middle?  I'd be interested to know what the moisture content is in the laminations.  Wet lams, shrinking as they dry may pull away from the glass.

I'd recheck the temp on those heat strips also.

[Vamp]

Hey Thanks, I sent them back to Elmont Bingham and he looked it over and even cross cut it and couldnt fint anything wrong with it. So he sent me back a new set of laminations  . So now we will see if the same thing happens with the new set. Lets hope not.. Thanks for your input.

[Crooked Stic]

Apply air pressure a little at a time not all at once.

[Vamp]

OK, Ill take that into consideration on the next bow. Thats one thing that was not mentioned. I normally use a hand pump but this time I used a compressor and it filled up pretty quick.

Thank you for your input crooked stic.

[bigbob2]

ditto that. i like to take mine up to 15#- 20# and let it sit couple minutes to ease any air bubbles out then go up to 70#

[Vamp]

Thats great to know. Ill be making another one tomorrow and Ill let you know how that works.

[7 Lakes]

This doesn't explain both limbs but make sure the metal pressure strip doesn't have a sharp glue bugger right where the crack appeared.

[Vamp]

If it was one crack then I would check but it is almost like if you were to curve wood with the grain and it split all along the grain. At least 8 crack on both sides on both limbs. The craziest thing