Hi! A couple of years ago I rebuilt my tank and sealed it with Kreem. Now I have some ugly blisters in the paint in a couple of places

, and have to fix this before riding season. Outside fixes should be relatively easy (I hope).
My question is what to do with the sealing. Can I re-kreem everything (clean and seal) or should I remove the old sealer and do everything from scratch?
Thanks in advance!