Greetings Grant, If you don't already have the tin I think you can still get it from an auto body supply. Be sure it's marked pure of course. You don't need to strip the whole bowl. At least when I've tinned stuff I was able to do small areas adjacent to already tinned areas. After cleaning real well regular paste solder flux should work fine. The rag can also be fluxed for wiping the tin. I have done this. I have heard that lard can also be used on the rag but I don't know. Try heating locally instead of the whole thing. Develop your technique with a piece of thin steel sheet. Cheers, Eric