Leak sealers

Leak sealer or crack-injecting systems, for cracks where movement is anticipated ... 

THERMOSETTING POLYMERS IN CONSTRUCTION APPLICATIONS 4.10 Polyurethane leak sealers and crack-injection systems... 

Patch the leaks using heavy-duty aluminum tape, insulating mud, or silicone sealers, and weld up any loose sheet metal. 

Since the individual cells of a spin-dependent liquid-electrolyte reserve battery are generally annular in shape and are filled by centrifugal force, the periphery of the cell must be sealed to keep electrolyte from leaking out. This sealing is typically accomplished by a plastic barrier formed around the outside of the electrode-spacer stack. For lead/fluoboric acid/lead dioxide batteries, this barrier is formed by fish paper (a dense, impervious paper) coated with polyethylene that melts at a relatively low temperature (similar to that used on milk cartons). Cell spacers are punched from the coated fish paper and placed between the electrodes. The stack is then clamped together and heated in an oven at a temperature sufficient to fuse the polyethylene, which then acts as an adhesive and sealer between the electrodes. 

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