The differences in Silicone sealants/gasket makers?

[clemsonfor]

Ok if i have been told o dont remember the answer, but what is the differences in all the clors of siicones? I know the red is a bit higer temp, but the colors all seem to have little variances of applications on the package? & read Cardoc describe the anerobic sealants before, but reeducation is good. So whats the difference between the blue, ultra blue, grey, black , red? Applications for each etc. I always use grey cause my father n law used it in his shop when he had one, not saying its right but i have had good sucess on everything from gearboxes to waterpumps, trannie pans , valve covers etc.

 

[JerryK]

Red is one brands 'high temp' stuff, whilst 'Ultra Copper' is Permatex's.... can't go wrong with just buying the Ultra Copper and use it on most stuff...as little price difference is there is.... [ Sorry, but two cents does'nt go very far anymore... ]

 

[MasseyWV]

Generally, I avoid using silicon and prefer to use gaskets and gasket sealer whenever possible.

 

[LD1]

The following is from permatex....
color.....................special property......max temp..........applications

Red........................High temp...............650*F....Valve covers, oil pans, timing covers, water pumps, thermostat housings, transmission pans

Blue.....................sensor safe...............500*F...Valve covers, oil pans, timing covers, water pumps, thermostat housings, transmission pans

Orange.......Sensor safe AND High temp....650*F...Valve covers, oil pans, timing covers, water pumps, thermostat housings, transmission pans

Ultra-Black.........Max oil resistance.........500*F....Valve covers, oil pans, intake manifold end seals, timing covers, transmission pans ALSO sensor safe and fast curing

Ultra-blue............Sensor safe................500*F...Valve covers, oil pans, timing covers, transmission pans, differential covers

Ultra-copper.........Max temperature.........700*F... Exhaust manifolds/ headers, valve covers, oil pans, timing covers, water pumps, thermostat housingsAlso sensor safe

Ultra-grey.....High-torque/high-vibration..500*F.....Valve covers, oil pans, intake manifold end seals, timing covers, water pumps, thermostat housingsdoes not say sensor safe


In reality, for 90% of applications, they can be interchanged. But there are "slight" differences and it is alot of marketing to give customers choices.

A few more notes:

all of the "ultra" RTV's are second generation. Supposed to have better flexibility and seal ability. The Non-ultras are first-gen.

All of them except Ultra-copper and Ultra-grey say they can be used on Transmission pans. But I would NEVER use a silicone on a transmission pan. EVER.

Ultra-black and Ultra-blue dont list water-pumps and thermostat housings for an application. So maybe the coolant does something???

Ultra-copper is the only one listed for exhaust manifolds. Allthough I would never use just a silicone for an exhaust manifold.

Red and ultra-grey are the only two not listed as sensor safe.

That about sums it up. So take your pick. I normally used red. No reason at all though. It works on everything I use it on. It isnt sensor safe, but the only place you would use it that would effect the o2 sensor is on the exhaust. And again, I dont use it on the exhaust. Now if you used it like on an oil pan or coolant system, and you "burned" one of those fluids, I suppose it "could" damage the 02, but I think you will have bigger problems to worry about.:laughing: In reality, I dont know if there is really any difference other than color. Maybe it is just to make you buy more sealants??? Cause unless you are in business and use them ALOT, you get one use out of them. Next time you need it, it is usually hardened up.

 

[Car Doc]

my .002

I use permatex high temp gray and only sparingly in the corners and mainly because I use gaskets as the main seal and I despise seeing orange and blue glue oozing out of everywhere its low class shoddy workmanship and is a waste of material.

Its personal thing and crappy mechanics seem to get it everywhere under the hood it just looks cheaply done to me not very professional. I call them glue artists.

I will occasionally use silicone instead of a gasket as long as I can get the surfaces super clean and all the oil out of the bolt holes it works as good as a gasket usually but never both gasket and silicone as a rule.

The super high temp silicones can be used to seal exhaust manifolds and mufflers etc but a metal to metal seal is the best on that stuff unless there is a donut gasket. There is a ceramic sealer that I use 99% of the time more than super high temp silicone on exhaust fwtw.

Anerobic sealer I like a lot and use it all the time for solid covers and tranny cases etc where no gasket is used just metal to metal. good luck hope that helps

 

[RickB]

my .002

Anerobic sealer I like a lot and use it all the time for solid covers and tranny cases etc where no gasket is used just metal to metal.

Absolutely.

 

[Pete Judd]

I guess that I am still old school, and use the permatex old black stuff comes in a small can with a brush in the cap. Maybe because I have a dozen cans still around and will cut the paper gasket out and apply that to both sides. Makes it tough to remove after a few years, but that is what a paint scraper and a wire bush on the angle grinder is for. Never have oil leaks, but have never used the newer stuff, but it looks interesting.

 

[Neat 1500]

my .002 The super high temp silicones can be used to seal exhaust manifolds and mufflers etc but a metal to metal seal is the best on that stuff unless there is a donut gasket. There is a ceramic sealer that I use 99% of the time more than super high temp silicone on exhaust fwtw. Anerobic sealer I like a lot and use it all the time for solid covers and tranny cases etc where no gasket is used just metal to metal. good luck hope that helps

most extractor systems sold nowadays say to use silicone of some description instead of gaskets. my mate has a shop and fits exhaust systems weekly to super high performance cars(supercharged and turbo GM stuff) and never uses gaskets, only high temp silicones ( he likes wurth stuff) most of the sealers/cleaners/treatments are all Wurth stuff.

 

[clemsonfor]

I dont think we have "Wurth" brand here, never seen it?

I have used silicone while working on my tractor recently as i am to lazy to make paper gaskets, if it is a critical area i would do it, but in the last week or 2 i have had the control valve off 3x! and that is a tiny flimsy gasket.

 

[Scooby074]

Wurth is here, but its pretty much industrial, sold by reps. Some places have it OTC though. Great products and they sell much more than just gasket makers, everything from ratchets to screws.

As to "silicones", i like Permitex Right Stuff.

If you have a solid, machined flange type surface, its hard to beat Loctite 518.