Dow 94-011 Fluorosilicone Channel Sealant

Application

Although any high pressure sealant gun may be used, the No. 223 Grover air operated aircraft sealant gun is recommended by the U.S. Navy and Air Force, and is covered by a national stock number for both branches. The gun is made by Grover Manufacturing Corporation, Montebello, California 90640. To utilise the cartridge, the sealant container supplied with the Grover gun must be replaced with a special Semco Cartridge Adapter Kit, available from Semco P.O. Box 61037, South Station, Los Angeles, California 90061. The adapter is easily attached and has been assigned national stock numbers.

DOW CORNING 94011 Fluorosilicone Channel Sealant is injected from the gun directly into the channel, port by port, so the channel is filled sectionally. Starting at either end of the wing, the first two ports are opened. The sealant is injected in the first port, travels the length of the channel between the ports (usually 1015cm), and exits from the second port. The first port is then closed and the third opened. The sealant is then gunned into the second port until it exits from the third port. The procedure is followed until the entire wing channel has been sealed, section by section. With the exit ports opened, the sealant will not be forced to the faying surface or into the fuel tank, the exiting sealant indicates a fully sealed, leak free channel section. When injecting DOW CORNING 94011 Fluorosilicone Channel Sealant, the gun nozzle should be in direct contact with the port. The use of a hose connection between the gun and injection port should be avoided, as it considerably reduces outlet pressure. If it is impossible to place the gun nozzle directly into the port, and a hose must be attached, the following suggestions should be followed: Use as short a hose as possible.

Increase the input pressure to permit the maximum allowable output pressure at the nozzle if it can be done safely and is permitted by the aircraft manufacturer.

Inject over as short a distance as possible.

Usually the port diameter is smaller than the channel is wide. This diminishes the sealants flow rate from the port. The size of the grease fitting used to inject the sealant and the exit port diameter may contribute to a slower flow rate. For example, if the exit port is 6mm in diameter and the I.D. of the grease fitting is 1.5mm, the exit bead will be very large compared with the injected bead. The operator should consider a reduced rate of exit normal. Do not skip ports. DOW CORNING 94011 Fluorosilicone Channel Sealant should not be injected beyond the next port because of lack of back pressure that develops. Laboratory tests have demonstrated that forcing the sealant 30cm through a channel can take seven times as long as it would to move the sealant 15cm along the same channel.