We (IAP) have seen dozens of threads with the CA "cracking like glass", sometimes long after the pen was made (so for those who have not had the problem, you might want to add "yet" to your statement).
And we have had many "solutions" "decided upon".
Fact is, no one KNOWS what causes the problem, here is a partial list of factors to consider:
Temperature and humidity when pen was made
Water content of the wood when it was made
CA consistency (thin, med, thick)
Was accelerator applied (including BLO)
Brand of accelerator vs brand of CA
Age of CA
Age of accelerator
Number of coats
Actual build-up depth in thousandths of an inch
How were the ends treated (potential for humidity to affect wood)
Tightness of components when pressed in
Type of pen made (kit type)
Diameter of kit tubes
Handling of pen:
Was it ALWAYS next to the owner (body heat is somewhat constant)
Was it left in a car or a purse
Temperature and humidity at the exact moment it cracked
Exposed to sunlight?
Exposed to other chemicals?
And, of course how was it handled? Dropped on cement floor?
Cyanoacrylic is formulated to be a quick acting adhesive. One property is it dries clear. But, aside from one company who made a "special formula" for finishing, which had problems from the start, I have seen no industry experts condoning it's use as a finish.
So, don't be surprised when it fails.
When you see statements of "this is what caused my failure", realize there are dozens of variables and someone has chosen only ONE of them as THE cause. While he could be correct, he is overlooking dozens of other possibilities.
