When searching for a gasket sealant, keep in mind that they're mainly used to seal gaskets, as the name suggests. Meanwhile, gaskets are the devices that bridge the gaps between mating surfaces that are less than ideal or even downright leaky fit.
The loose connections become tight, but to make them even tighter, you have gasket sealant to seal the deal and make everything as tight as possible with zero leakage. Gasket plus sealant is usually all you need in order to make the most stable of connections until, of course, your car blows a gasket or two.
Searching for a Gasket Sealant
- Shellac: This is the sealant of choice for cardboard or paper gasket. The Indian Head sealant works best with gaskets that are mounted in low temperature and/or low pressure conditions. It's not the ideal sealant for environments that can go up to 300°F to 350°F. It's a good sealant for thermostat gaskets, time cover gaskets, and differential cover gaskets.
- Anaerobic Sealers: This is for applications with no outside air present to make the sealant dry faster. It was once used for a non-corrossive gasket maker brand exclusively. It's now used for filling small imperfections or conditions where the gasket isn't accessible or available at all.
- High Tack: The high tack gasket sealant is usually fond with a brush-top bottle or in tubes, like strong adhesive or superglue. It's superior to shellac due to its ability to sustain sealing for up to 500°F in hotness. It's tacky all throughout its lifetime and can resist corrosion from kerosene fuel, propane fuel, and diesel fuel.
- RTV Silicone Sealers: This comes in caulk-gun cartridges, gel tubes, and aerosol cans. It's volatile in room temperature. However, it can seal up gaskets or serve as a sprayable/spreadable gasket on its own. 500°F applications require blue, black, and gray sealers. 650°F applications use the orange and red. Copper is for 750°F applications.
- Form-a-Gasket Sealers: You can avail of the non-hardening, slow-drying, and brushable sealer, which can seal metal flanges, machined surfaces, and solid gaskets in thin or thick coats. The fast-hardening, fast-drying one can permanently seal block expansion plug installations, threaded connections, and metal-to-metal gasket connections. The slow-drying, non-hardening one can work on paper oil pan or cork gaskets.
- Hylomar: The 30-year-old polyester urethane sealant can deal with 500°F temperatures without becoming hard or setting itself unto the gasket permanently. It's tacky and non-setting. It can be utilized for repeated reassembly or disassembly of gaskets as needed by mechanics. It's the sealant of choice for racecars.
- Copper Gasket Sealant: You can brush or spray this gasket sealant. It's fast-drying and fast-acting with metallic content suspended within it to make sure the seal is tougher and the heat dissipates better at a rating of 500°F. It also ensures superior heat transfer with mating surfaces connected by the gasket like cylinder head or exhaust manifold gaskets.