Magnesium anodes are generally provided with a low resistivity backfill surrounding the anode. The backfill material provides a uniform environment for the anode and enhances performance by extending life and lowering the local resistivity. The prepared backfill consists of a mixture of 75% gypsum, 20% bentonite, and 5% sodium sulfate. Gypsum is primarily a filler material, bentonite absorbs and retains moisture, and sodium sulfate lowers backfill resistivity. The backfill is contained around the anode using cloth bags. The packaged anode is installed directly into the soil and then connected to the structure by a wire. Anodes are normally provided with ten (10) foot of #12 AWG wire.

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