Duralac is a plastic insulator and sealant designed to prevent electrolytic corrosion that can occur when two different metals are coupled, such as:
- Aluminum cleats fastened with stainless steel screws.
- Aluminum or brass winches fastened with stainless steel bolts.
- Stainless steel accessories mounted on aluminum shafts using rivets or screws.
- Fairleads coupled with metal fasteners of a different metal.
Duralac paste creates an effective barrier that inhibits galvanic corrosion between dissimilar metals. It is easy to apply with a brush and requires no dilution. The traditional version contains barium chromate, while the "Duralac Green" variant is chrome-free, offering a more environmentally friendly alternative.