I got a 2007 Suburban in 2019 and wound up putting a Jasper engine in it and we went to Montana with another couple. When we got there I noted a small leak on the right side of the transfer case extension.

Upon closer inspection I found a pin hole in the casting so I mixed up some Marinetex and patched it when we got home. Has held up fine until last Sunday as I noticed it was leaking again.
Today I got it on ramps and dried it off all and drove it a mile and was able to trace the leak to the original location but I am thinking the original hole I repair was on a different surface I ground off most of the original Marinetex, scrubbed the surface with acetone and mixed up about half a teaspoon of Marinetex and reapplied it and I have a heat lamp on it as the temp here is not that warm.
I have also used Marinetex to sear gas tanks in fire engine and generator fuel tanks. I put the unused portion into a jar and covered it with gasoline about 8 years ago and the Marinetex is still in place and not dissolved.
Will be interesting to see how long this fix holds up.

As I understand it Marinetex was designed to repair fuel cells at sea and the US Navy loves it.