more info on CA
Would you coat everything, as in a segmented bowl with many seperate padauk and other species (which is my interest)? we have not heard from any of the people that do segmented work with lots of interspersed species. Fred mentioned the oil from padauk can migrate through some glues.
I have not been a fan of CA since i heard that museums have stoped using it for restorations - it breaks down in time - although the time span has ranged from 5 to over 20 years, the jury is still out.
here is some fascinating info - this was from a modelling site of the US Navy, as they restore model ships.
"CA was formulated by accident in 1951 by two scientists working for the Eastman Kodak Company. They were trying to come up with a stronger, clearer, and more heat resistant acrylic plastic for jet plane canopies. By 1958, Kodak, which called it Kodak 910 Adhesive, developed a way to manufacture this material commercially, outside the laboratory and in quantity. It may have been instant "glue," but it was far from an instant hit in the marketplace. Apparently, 910 was not widely marketed for domestic use at first; rather, the first applications were in the manufacture of cameras, electronic instruments, automobiles, and atom bombs. In 1966 during the Vietnam War, a surgical grade of CA was used by some combat medical teams. It worked well, but the product was not approved by the Federal Drug Administration for general medical use because it appeared to cause tumors when implanted in rats. Public interest in CA products for general use began to grow when the inventors suspended Gary Moore on live national television with a single drop. That feat is still used in some TV commercials.
Early on, CA was prized highly for its optical clarity. Because it remains largely invisible when used to repair broken glass objects, museum conservators regularly used CA for glass repairs. But then they found that some types of glass deteriorated the adhesive. So, while CA is still used in museums for temporary repairs, conservators now use epoxy or clear polyvinyl acrylic adhesives, which are rated class A, for permanent repairs.
There are a lot of different CA permutations now being formulated that have particular viscosities and cure rates for specialized applications. Cyanoacrylates can be divided into two main types‹methyl and ethyl‹plus, there are also propyl, butyl, and methoxyethyl types. They vary in consistency from watery to gel-like. Gap filling depends on the type of CA used. Certainly, viscous CAs can fill gaps well. Regardless of the type, CA is nearly a class A substance whose magic lies in its ability to form superior long-lasting acrylic bonds between small surfaces.
CA does have some limitations. It is brittle and has little strength in shear, being especially sensitive to impact. Some types of CA are not waterproof, and, like all acrylics, CA generally has a small tendency to absorb water, though this has not been shown to be detrimental. We also know that CA is gas permeable, and therefore does not prevent airborne acetic acid from attacking lead, or ferrous metals from rusting.
Commercial-grade CAs, repackaged in smaller quantities, are no doubt the type sold by hobby suppliers. We have used industrial grade methyl and ethyl CAs on navy models for small jobs and quick repairs since 1983. Our uses have included coating bare brass and Britannia fittings and securing rigging line, and we have not seen any evidence of its giving way. Although there has been some concern that accelerants weaken the bond, we frequently use accelerants, or "kickers," to speed up the cure, and have not noticed any difference. However, CAs should not be used exclusively in modelbuilding, however tempting that might be. For larger surface bonds, like between the lifts of bread-and-butter hulls, or between block superstructures and decks, I recommend using another adhesive. "
Regards
Ray
For example, the work of Eli Avisera as seen on the cover of The Woodturners Catalog 2004/2005 from Craft Supplies USA shows NO leaching from the ebony or purpleheart. Sharp and crisp.
