Hi. What I'm looking for is some sort of sealant that will be completely airtight. A liquid. The idea is to be able to cut a potato in half and completely cover it in some sort of sealant so that it stays that way for a very very long time. I know artists use a type of sealant to keep their paintings and such, but could that really preserve food? I was thinking of maybe using that with an outer coat of epoxy or superglue.