Silicone vs grease vs PTFE - where to use?

[cmedsailor]

Silicone spray
PTFE Teflon spray
Grease spray

Could someone explain me in simple words where each of the above products can be used? I once sprayed the nylon bush of my stiff rudder with silicone spray and the rudder really got very stiff (it was like spraying it with glue!). Immediately afterwards I sprayed it with WD40 and grease spray and was back to normal.
But I am really confused what to use and where.

(blocks - I just use hot water to avoid any damage to lines)
Thanks

 

[BlueChip]

I think silicone and regular grease do much the same thing, both are non drying and will attract dirt and muck.
I use silicone grease a lot and find a tube of this very handy on board and lasts ages, in particular the sail slides really appreciate a thin coating from time to time.
PTFE dries to a powder coating with a very slippery surface - think non slip frying pan - its nowhere near as effective and long lasting as grease but is very handy to have around on board.
I am guessing that whatever solvent is used in the silicone spray caused your rudder bushes to swell slightly and bind. I doint believe it was the silicone

 

[cmedsailor]

I think silicone and regular grease do much the same thing, both are non drying and will attract dirt and muck.
I use silicone grease a lot and find a tube of this very handy on board and lasts ages, in particular the sail slides really appreciate a thin coating from time to time.
PTFE dries to a powder coating with a very slippery surface - think non slip frying pan - its nowhere near as effective and long lasting as grease but is very handy to have around on board.
I am guessing that whatever solvent is used in the silicone spray caused your rudder bushes to swell slightly and bind. I doint believe it was the silicone

My theory (!) with the rudder bush was that silicone spray simply absorbed any dirt over there and the combination dirt and spray was flown down between the rudder shaft and bush making it very stiff (I didn't remove the rudder, I sprayed the rudder shaft above the bush and hoped that would flow down and lubricate it). I then sprayed with WD40, just to clean it and eventually with grease. Probably if it was clean from the first place, silicone could benefit it. I don't know.

But anyway back to my question. If silicone attacts dirt and muck as you said, why use it a lot? Why not teflon? Oh, I am lost with so many things around.

 

[BlueChip]

My theory (!) with the rudder bush was that silicone spray simply absorbed any dirt over there and the combination dirt and spray was flown down between the rudder shaft and bush making it very stiff (I didn't remove the rudder, I sprayed the rudder shaft above the bush and hoped that would flow down and lubricate it). I then sprayed with WD40, just to clean it and eventually with grease. Probably if it was clean from the first place, silicone could benefit it. I don't know.

But anyway back to my question. If silicone attacts dirt and muck as you said, why use it a lot? Why not teflon? Oh, I am lost with so many things around.

Apart from the sail slides where i find silicone grease works much better than ptfe and lasts longer, I generally only use it below, where I need a waterproof seal or where it cannot pick up much muck - electrical connectors, hinges, hatch locks, padlocks, log impeller etc etc

 

[Deleted member 36384]

I was advised that certain "greases" cause nylon bushings to swell slightly, hence silicon is good where such bushings require lubrication.