Thanks for the suggestions guys. It's strange though, because it's not that there is any sap left on the blade and it was not sticky at all. I guess there is some component in the sap that causes an almost immediate chemical reaction? If one were wanting to get an almost immediate patina on a blade, this seems like it may be a good way to go about it (presuming you would be able to coat the enire blade). Does anybody else know what I'm talking about, or why this happens? It was an oak tree by the way.