Chemical gasketing products are used to make gaskets in place of cut or preformed gaskets, or to seal gaskets. There are basically three types: anaerobic gasket makers, RTV silicone gasket makers and gasket sealants.
Anaerobic gasket makers are used primarily for OE specified applications on rigid components such as water pumps, thermostat housings and transmission covers. They are designed for use on close-mating parts with gaps of less than 0.10 inch.RTV silicone gasket makers are extremely versatile and can be used to make custom form-in-place gaskets on almost any type of assembly. They come in a wide variety of formulations such as high temp, torque retention, sensor safe, low odor and oil resistant. Review the application specifications to make sure you're recommending the right one.
Gasket sealants are used to condition and extend gasket life. They help seal leak paths and improve the gasket's resistance to oil, fuel and fluids. Gasket sealants also are excellent installation aids and can be used to help position and hold large cut gaskets in place during assembly.Prepare surfaces properly
This is a critical step for any type of chemical gasketing. Unlike OEM assembly lines, where both cut and form-in-place gaskets are installed on new components under ideal conditions, your customers are dealing with used parts, along with dirt, grime and grease. Some components may even have damaged or deformed sealing flanges.Here's how your customers can make sure they have the best surface conditions for a reliable seal:
- Remove the old gasket material. Recommend a chemical gasket remover to dissolve and remove sealant, cut gaskets and anaerobic material. This will minimize the need for scraping or chiseling, which can damage the flange surface. Note: A gasket remover is not recommended for use on RTV silicones. A special silicone stripper is available for that purpose.
- Clean all flange surfaces. A good, solvent-free parts cleaner will do the trick.
- Dry surfaces thoroughly.
Apply gasketing material correctly
The size and consistency of the bead is important and will affect both the reliability of the seal and the cleanup afterward. Here's how to do it right:
- Cut the nozzle on a slight angle.
- Make the bead size between 1/16 inch and ¼ inch. Note: Cut the smaller diameter at first and test the bead size, then adjust as needed.
- Apply a continuous bead to one of the flange surfaces, making sure to circle all bolt holes.
- Check the directions for use on the package. Some gasketing products do not require cure time and can be put into service immediately, while others may require up to 24 hours for curing.
- Clean up excess gasketing material.
To learn more about gasketing technology from Permatex, visit the company's Web site at www.permatex.com/trainingvideos.htm.
Jeremy Beck is a product manager at Permatex, Inc. and is responsible for its gasketing, sealants, elastomers and lubricants businesses, including new product development and supply chain management.
