Why silicone?
 

I learned while owning a RV that silicone is crappy cheap shit. Why do I hear people using it for repairs?
Iv always liked permatex #2 because it doesn't harden.. But what do I use on the permanent side of the gasket? It may seal first time, but silicone peels off like nothing..

Thanks!

What kind of repairs or "gasket" are ya referring to? There are alternatives to silicone, depending on repair, I will use either "Gorilla" silicone, GE silicone, or for permanent repair I will use Loctite Polyurethane sealers (either black urethane "roof flashing", white urethane, beige, or gray). All come in cartridges for use in a caulking gun. Hell Ive even used 3M window urethane, used to install windshields. for repairs or waterproofing. All this stuff stays pliable and is even paintable. The Loctite stuff, Ive used also as gasket sealer or in place of a gasket in certain automotive repairs. Been using this stuff for nearly 25 years. Always worked for me...……...

Thanks Redd.. In my case I'm adhering the timing case cover gasket to the cover before install, where I will use non hardening permatex #2 on the case side. I bought some more "the right stuff" since I used it almost exclusively on my first 12 valve rebuild with good luck, and just glued and torqued it to ten foot pounds.
Later I'll drop the trans fluid and use the right stuff on the pto cover.

Are all those building products you mentioned suitable for automotive?

The polyurethane definately has worked for me for many years. Urethane, once cured is still pliable, not hardened, and will definitely work. hence no leaks. Ive used the stuff for water pumps, valve covers, diff covers, trans pans, intake manifolds, oil pans, etc... I will admit that if ya have to remove those listed parts for whatever reason, its a bit of a challenge and a bit more difficult. For me, I HATE LEAKS of any kind, so this stuff has never failed me where silicone sealers have. The newer engines all have reuseable gaskets and O-rings in certain areas, but I don't mess with those gaskets and O-rings. The most you can do is just give it a try and see for yourself.