Old thread I know but.....but autobody steel wool......take a pad and gently pull it apart untill you have a long mess of steel wool. Massage it for a bit to get the broken bits out ( there will be some). Hope your wearing your gloves and glasses, now take your favorite high temp RTV and work abit into your steel wool , proceed to twist the steel wool into a yarn like rope. wrap your up-pipe with one (tiney leak) or two wraps (decent leak) and use a stick/screwdriver/whatever and tuck the rope seal into the union. tuck tightly and pack it in. allow to set. A home made flexible seal that comes apart easily.