To Drill, or not to Drill, that is the question. :) I'm talking about Shells of course! This is a recent concern, of questionable origin, and here are my thoughts on the subject:
1. Piercing (drilling) the shells is the traditional way of the ancient Hawaiians. They couldn't go to the hardware store to buy glue. They used sharpened pieces of bone, tooth or other shells to pierce holes in the shells so that they could string them into leis. They often used their own long hair as a stringing material!
2. Piercing the shell is always done in the hinge area which is the thickest, strongest part of the shell. The hinge area is the oldest and least fragile part of the shell, the shell grows outwards from the hinge towards the scallop edges (which are the thinnest & sharpest part of the shell).
3. Piercing or drilling a hole in the hinge area of the shell does NOT weaken the shell. In fact, many, many shells are found with natural holes in them. These natural holes are the result of predatory Cone Shell attacks as the Cone tries to consume the scallop within the shell.
4. A ridiculous claim has been made that drilling holes in the shells is "disrespectful". All I can say to this is - I am 100% sure that the amazing Hawaiian women of the Forbidden Island of Ni'ihau, the most talented and revered Shell Lei Makers in the World, would be very, very hurt at that statement, as 100% of their shells are pierced...! Just google "Niihau Shell Lei Makers" to watch numerous YouTube videos of them at work, piercing their shells! This is the way they have made their shell leis for many Generations.
5. Adhesives - do they work or not? Well the answer is yes & no. I would not want to trust my prized Sunrise Shell to a crafter's adhesive, even the most popular E-6000 brand. Any flexible adhesive should be avoided at all costs! The only type of adhesive I would use is a 2-part epoxy, but even this has some drawbacks:
5.a. An epoxy, or any other man made material for that matter, is only as good as the manufacturing process with which it is made. As a former Manufacturing Quality Engineering Manager (10 years with Apple Computer, 10 years in the Automotive Industry) I can tell you with absolute certainty that no process is foolproof. If one or more components/processes of the epoxy is defective, so is the epoxy bond, your shell will fall off.
5.b. Epoxy has a shelf life. Can you be sure that the epoxy used on your shell was used within its dated shelf life? If not, the bond is not secure, your shell will fall off.
5.c. Epoxy must be mixed absolutely perfectly. If the mixing process is not followed per the product's specification, the bond is not secure.
5.d. Epoxy must be used within the manufacture's specified climate parameters - that is, temperature and humidity. Here in Hawaii it is frequently hot and rainy so this is a very important concern that often goes ignored by many who are trying to 'pump out' lots of jewelry as quickly as possible.
5.e. Preparation of the surfaces to be epoxied is extremely important. Surfaces contaminated by sweaty hands, lotions, oils, soaps, acids, wax, salt water, food - anything, will cause the epoxy to become separated from the shell surface, and you will lose your shell.
5.f. Storage of the epoxy is also important. Has the epoxy been stored outside in the sun, in the hot trunk of a car, etc...?
5.g. Epoxy does not last for a lifetime. Eventually it does become brittle and will crack. Even clear epoxy tends to turn yellow rather quickly, that is why some people like to use grains of sand to hide the yellow color, but this is merely a cosmetic issue.
5.h. Epoxy will soften with heat, even when used correctly. I would not trust a shell that has been made with epoxy in a hot tub or jacuzzi. Even extremely hot showers or prolonged high body heat can soften the epoxy bond.
So, do I use epoxy? Yes, sometimes I do. I like my design of the "floating" Sunrise Shell with the Puka Shell epoxied to the back so that nothing is seen except the beautiful Sunrise Shell. But I also trust my 20 years of experience in Manufacturing Quality Engineering, and I am confident in my ability to follow the process to the "T" and to inspect the products that I use for shelf life and all other manufacturer's specifications and process parameters, to ensure a secure bond.
To sum this discussion up I will say this: If you want to wear your shell as jewelry, and if you want to wear it all the time in all weather and temperature conditions, have your shell pierced just as the old Hawaiian Ali'i did and enjoy it for a life time! If you prefer the look of the epoxied shells, you have been informed of the potential failures, and you should be confident in your jewelry maker's ability to follow all the epoxy processes correctly.
I hope this note has been informative.