 |
The Polywater Laboratory has released yet another in a series of new application training videos. This latest clip is an FST Application Video in 4-Inch Conduits. It demonstrates the proper use of FST Foam Duct Block in 4-inch conduits using the larger 250ml cartridge (catalog #FST-250), which fits standard caulking guns. The 3-minute video explains that conduits with IDs of 4 inches and larger require a two-step process to seal. The instructions include the usual admonitions to wear safety glasses and gloves, and to adequately prepare the internal conduit surface by abrading with a sanding cloth or wire brush, and cleaning with Type HP solvent wipes. The first piece of damming foam is then sized and placed 5 inches inside the end of the conduit with a positioning rod. The second piece of damming foam is wrapped around the cables and placed inside the conduit flush with the end, creating a cavity. Using the cartridge and static mixing nozzle in a high-ratio caulking gun, approximately half of the required quantity of FST Foam is injected into the cavity. After waiting five minutes the rest of the FST Foam is then injected using the same mixing nozzle. The key to successful seals in larger ducts is the two-step injection of FST Foam. The 5-minute wait between injections allows the first quantity of foam to expand inside the cavity and harden just enough to create a platform onto which the second quantity of foam is poured. This ensures that the entire cavity is fully filled by the foam expansion, creating airtight and watertight seals. Make the second injection from the top side of the outer damming disk so that the liquid FST falls onto--not into--the expanded first injection. |
