Waxing the zippers on your dry suit is extremely important to ensure that the run smoothly up and down their entire range and seal properly without breaks. If the zippers on your dry suit don't seal because of sand or other debris on them, then you don't have a dry suit. It's a human sized water bag, and if you find yourself swimming, it will fill up very quickly. I don't play around with the suit upkeep when I am out on an expedition because it is an essential item for the success of the journey if it fails and you can't repair it in the field, it's probably the end of the journey, or a considerable risk. Therefore I wax the zippers every day.
The Gear Aid Zipper Wax lubricants are cheap and light, so carry five or six of them with you, so you don't have to be stingy.
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