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.
Are you contagious? Though people who haven't had chickenpox can catch that condition from you, the shingles itself isn't contagious. For reasons that experts don't really understand, the pain of shingles lingers for some. If the pain lasts for at least 3 months after the shingles rash has healed, a person is diagnosed with PHN. In some people, the pain will subside. In others, it won't.