Permatex Aviation Form-A-Gasket No. 3

[glcaines]

Is Permatex Aviation Form-A-Gasket No. 3 a good substitute for Sealing Compound, Type III, Mil Spec S-45180? I've been using this as a sealant on the steel parts when installing pinion seals in differentials, bearing seals in axles, etc. for many years, but now wonder if there is something better.

[rickf]

IT is perfect for putting on the outside of the seals both as a sealant and a lubricant to help with installation. It is the only thing I use on composite gaskets like water pump, thermostat gaskets, Intake manifold gaskets, differential covers. I will usually use it on the valve cover side of a valve cover gasket to keep it in place the next time the valve cover is removed but leave the head side bare to seal against the head, this is assuming cork gaskets. Neoprene gets no sealant. Somewhere else I use it may surprise you, I use it on all of my coolant hoses . Again, it lubricates for easy installation but also where you have aluminum housings like the thermostat it prevents corrosion and keeps the hose from seizing to the housing. Same with all the other connections, it makes it much easier to remove a couple years down the road.

[halftracknut]

I use permatex No. 2 and Indian Head Shellac....htn

[rickf]

Shows how old you are HTN. I always dreaded the days I needed to take an engine apart that was put together with that stuff! I had a 6 cylinder Ford Falcon head gasket that was installed with Indian head and I literally had the front of the car hanging in the air from an engine hoist attached to the head with no bolts in it as I beat and pried on it to get it off!!

[halftracknut]

I think it smells good too If in doubt use more................htn

[1SGCAV77]

When I purchased my #3 at local NAPA I was asked what “classic” I’m working on. Clerk said older customers buy this product.

[rickf]

Did you ask him what he uses on his "modern" vehicle? Probably silicone and you will most likely find his oil pickup half clogged with it.