The Most Tested Expansion Joints in the Industry

Field Splice Procedure for Thermorubber Seals

This simple step-by-step procedure guides you through a field splice of any of EMS’s Thermorubber (Santoprene®) materials.

• · Measure the seal to the length desired. Execute a clean, smooth cut across the seal profile. Grind ends flat to assure that the ends are square and clean. Remove all excess grinding dust using compressed air and wire brush.
• · Find a nearby electric outlet and plug in the electric platen. Multiple extension cords diminish the amount of wattage available to heat platen to between 400 Fº to 425 Fº. Keep out of direct wind; this causes premature cooling of the aluminum heat blade. A meat thermometer will work well to determine the temperature and is readily available in most hardware stores. Some heat platens have a regulating knob on the device.
• · Set seal into forms and secure so that part is firmly seated. Allow approximately ¼” of “virgin material” to protrude out of the form. Simultaneously repeat process on opposite side to be spliced.
• · Move both ends of protruding seal towards the preheated platen. Gently but firmly press the ends of the seal against the Teflon coating of the heat blade. As the material warms up, you will observe a “melt ridge” beginning to form on the top and sides of the seal body. Depending on the size of the seal being spliced, the amount of time against the heat blade will be determined by the appearance of the “melt ridge”. When an even ridge of about 1/8” is observed, slowly pull back the two ends of the seal being melted. Remove the heat blade, and align the ends of the seal splices together and gently press them against each other. Hold in position until the part cools. While the ends are being held together and cooling, have another person gently “crimp” together the flashing area using a pair of needle-nose pliers.
• · After the splice has cooled to room temperature, carefully remove the spliced sections from the forms. Use side cutters to remove excess flashing due to pliers crimping.
• · Turn the part over to view the underside of the spliced connection. If there are areas where the splice did not take as well as the top, reheat the specific area with a heat gun and gently crimp the heated edges using the needle nose pliers.
• · Although the part is spliced together, treat the splice with additional care when handling and/or placing into position at the joint location.