It would be informative and helpful if folks here shared their knowledge about the hazards of stuff we work with. Mercury in bluing solutions has come up, but there are surely other materials and substances that require some precautions. I expect breathing the dust from sanding wood is not contributing to a long life. How about dust from carding during bluing? I now wear disposable plastic gloves for many operations but started doing so mainly to make it easier to wash up. Checkering, especially with power tools, must release a mixture of wood and finish materials. Any specific hazards and/or their minimizing could be a big help.
