Spiral Wound gaskets can be fabricated of any metal which is available in thin strip and which can be welded; therefore they can be used against virtually any corrosive medium dependent upon the choice of the metal and filler.
Theoretically, it is no longer contagious when there is no more fluid leaking from the sore, and no new blisters are forming. However, I always assume that a cold sore is contagious until it is completely healed, and to the best of my knowledge I've never transmitted the virus to anyone else. Abreva is a very good remedy. If applied when you first feel the tingle you can actually prevent the cold sore from erupting into blisters.
Herpes viruses are spread by touch. If you get cold sores, it is very important to wash your hands often and keep your hands away from your face. A cold sore is contagious during the prodromal period and when a sore is visible, but herpes viruses can be spread even when there are no symptoms or sores.