Yes Al, thought I would post a note in support of caution regarding HF.
In my other life I was Involved in the construction and startup of a chemical plant that involved the acid as part of the process. The operators worked in self contained 'Greylite' suits but if there was a leak (usually a pinhole in the gloved area) the skin would later start to burn and would only stop when it reached the bone as calcium neutralized it. The first aid protocol was to inject calcium chloride between the acid and the bone. This was very painful if the acid was under the nail.
I realize this post is far afield of the thread but I think it is important enough to make a strong point.
Ray