Its not just for sealing out rain any more.
I have a large granite rock at the end of my driveway next to the street with a nearly vertical face. I dragged it out of the woods and put it there so I could put brass street address numbers on it.
The problem is that I am hesitant to drill any holes in it. Might it crack the rock? What if I want different numbers with a different hole pattern? I would have ruined a very nice rock.
So I glued the brass numbers on with various adhesives. They all failed in a short time. Hot glue worked the best but still does not hold for more than about 6 months. I think the hot/cold cycles works it loose. Most certainly the news paper delivery person aims for those numbers to try an knock them off!
A few months ago it had fallen off and I we had a family gathering approaching so I had to get it back on. I was running out of time and was going into my shop to get the hot glue gun once again when I spied a roll of butyl tape that I use on my U-Haul
Could it be? Could this sticky stuff actually hold the brass number onto a rock? I cleaned off all the old hot glue, cleaned it with lighter fluid and stuck it onto the rock with a strip of butyl tape. It stuck very nicely.
It got me through the family gathering. But surely when it got hot it would slump off. Well, today it hit about 98 air temp plus direct sun. Still sticking securely. We will see how it holds up this coming winter. But no hurry...really...