When I first started wrenching that permatex aviation sealer was what the counter guy handed you for sealer. It's OK, my prime gripe is that it dissolves in gasoline. I've been burned when some damned PO used it to seal a petcock and or carb gasket, the gasoline dissolved it, pulled it through the system and plugged every fricking jet, orifice, and passage, in the carbs leaving me to fight that gunk back out, Grrrrr.
What Jim and I trade a few pleasantries?? Never happened.
Apparently Hylomar is still closely held not sure if it's patented or the formula is secret, and there have been several changes in who is allowed to sell, distribute it in the USA. Been using it for 20 years and am on my second small tube there is still some in the first tube so I have one in the garage, one out in the shed. For me it never goes bad. sub zero 100 degree temp swings for years it stays just like the day I opened the tube. I'd hate to guess how much rubbery silicone seal I've thrown away over the years. Don't use sealing goop when assembling fuel systems. If you gotta seal a pipe thread, Teflon tape cuz it don't dissolve. Shrug.