RTV Silicone verses Gaskets

Discussion in 'Engine, Fuel and Exhaust' started by pjones, Nov 12, 2009.

  1. pjones

    pjones Member

    Does RTV silicone provide a long term gasket alternative in the low to medium temperature applications as compared to using gaskets?
    Also I was wondering if running my bike without baffles contributed to the whitish exhaust valve stem in the front cylinder?

    NEWHD74FAN Experienced Member Retired Moderators

    While RTV silicone is great stuff, your question should be more why use gaskets rather than an RTV silicone sealer. Reason, in an ideal world mirror polished surfaces would seal by mating them together strongly AND be able to take them apart for service. There in lies the rub...gaskets make up for uneven mating surfaces and compensate for temperature, vibration, fastener stretch/tension and such, the real world subjects to mated sealed surfaces YET allows ease of maintenance and reinstallation.

    One of the problems that would happen if you used sealer would be gasket not letting loose when trying to take mating surfaces apart, the other problem is cleaning and prep before remating the disassembled parts after service, not easy if gasket or sealer if truly "stuck" to one or both surfaces or traces are left over to not allow the new contact surfaces to mate cleanly.

    Stick with using gaskets and only use sealer or grease as an assembly tool and only on the removable surface, NEVER on the fixed surface lest you make it next to impossible to get off or clean up when servicing.
  3. LEOG

    LEOG Member

    Pat. I assembled the cases on my 64 Sprty back in 84 using loctite gasket eliminator. no leaks yet and she's been used alot. However, the mating srfaces of the cases were lapped to ensure they were reasonably flat prior to assembly. Those cases were assembled at the factory with no gasket. RTV has its uses and advantages but gaskets are required and should not be eliminated in my opinion. Sometimes ya gotta do what ya gotta do. Remember "Good Judgment comes from Experience, some Experience comes from Bad Judgment"

    Keep the Dirty Side Down Ride Safe
  4. kemo

    kemo R.I.P

    Many people use too much silicone, and when they do an assembly the stuff oozes. They don't realize that the stuff also oozes in and what happen then is the stuff starts floating around with the oil and coolant and plugs oil ports and gallies. Never use silicone on an automatic transmission, use grease to hold a gasket from sliding. The dealer put a new enginge in my truck once and the thing started to overheat. Drove me nuts trying to figure why. Changed the stat, was worried that they put the head gaskets on wrong, etc. I finally took the rad down to the rad shop and they pulled the tanks off and 1/2 of the tubes were plugged. If I do use silicone I use very little.
  5. Crocker

    Crocker Active Member

    I alway prefer using the proper gasket, but in a bind they are some good gasket alternatives out there , Permitex makes a product for Napa autoparts called the Rite Stuff its by far one of the best gasket makers I have used, it is rated for just about anything you want to seal and the car makers use in assembly on car engines ,I have used it a number of times on diffrent applications and it is worth having a can around in your garage , Loc tite makes great products also just wish you could find a store that carries there whole line of what they make.with todays tech we are far beyond the days of cutting your gaskets for your primary cover from the cover of your telephone book , last year I had a head gasket let go on my backhoe I was not looking forward to tearing it down ,found a product you add to your cooling system figured what the hey I will give it a try it costed like $70.00 but I tell you it worked and is still going strong.
  6. Hoople

    Hoople Account Removed

    If you really mean the Valve STEM in the front cylinder, I would say no. How many miles is on your engine?
  7. Drumrguy

    Drumrguy Account Removed

    Usually when you put engine cases together you use a little sealant, but when you put cylinders, heads, rocker boxes, etc, you should always use the proper gaskets. Like everyone said, they are a little more forgiving than silicone, and a lot less messy. Who wants to look at a nice chromed out bike and see silicone everywhere, not me. JMHO.
  8. Jack Klarich

    Jack Klarich Expert Member

    R T V is a great sealer I would not use it on a Harley motor, only on exhaust joints like the MOCO did. Tha bad thing about RTV is it can slide around and possibly plug an oil passage bummer. I use it alot for making rear end cover gaskets in the auto industry works great till u have to clean the mating surfaces the next time.
  9. Drumrguy

    Drumrguy Account Removed

    yeah, that is a horrible job. I hate cleaning surfaces after using RTV.
  10. Jack Klarich

    Jack Klarich Expert Member

    Permatex makes a spray gasket remover that works good dont get it on your hands or paint