Water Bottle Stickers
I have been using a metal worker bottle to "collect" cute stickers I pick up when I visit new places. It makes for a great conversation piece, and acts like a scrapbook while still being something functional.
When I run out of room for new stickers I was thinking of trying to apply some kind of sealant on the outside of the bottle. I still want to be able to use it for drinking water though.
Does anyone have a substance to recommend for keeping my stickers safe?

You might want to try using a clear acrylic sealant spray. I've personally used Krylon but really any brand that claims its food safe should do once fully cured. Make sure to apply it in a well ventilated area (preferably outside) and give it ample drying time between coats. That should give your stickers a nice protective layer while still allowing you to use the bottle for drinking. Good luck this really does sound like a nice conversation piece lol
To piggyback on this, these sprays are not as waterproof as one would hope. I would recommend keeping it out of the dishwasher, and use gentle hand washing only.