The great zipper debate- waterproof or nah
Why I’m Moving from Uretek to Molded Tooth
A recent Instagram poll turned into a surprisingly discussion about one of the most overlooked parts of outdoor gear — zippers. Whether you’re an outdoor enthusiast or just gear-curious, there were a lot of opinions and valuable insights.
If you’re just here for the verdict: the shift away from coated “waterproof” zippers toward molded tooth is happening — and for good reason.
Weather-Resistant (Coated) Zippers —Uretek / AquaGuard
For years, coated zippers like YKK’s Uretek (aka AquaGuard) have been seen as the premium choice for high-end outdoor gear. They have that sleek, glossy look and a coating that helps repel water.
They’re most often sewn with the coated side facing out, which hides the teeth and gives a clean, modern look. Functionally, they help keep moisture and grit at bay, and they’ve been used across everything from ultralight packs to bikepacking bags.
But there’s a catch — literally and figuratively. Over time, that coating tends to flake, delaminate, or stiffen, and once it starts to fail, the entire zipper feels compromised. Many repair experts point out that “waterproof” doesn’t mean forever waterproof — especially since any sewn seam is full of needle holes anyway.
As one poll participant put it: “They're great until they fail”
And they’re right.
Molded Tooth Zippers —
Then there’s the other side of the conversation: molded tooth zippers (YKK VISLON). These are built from interlocking plastic teeth — more rugged looking than the sleek design of Uretek, and much tougher than most expect.
Multiple pros weighed in on this side of the debate.
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Neil Beltchenko and Miles Arbor from Bikepacking.com put it best: molded tooth zippers are “where it’s at.” They’ve seen it all - from gear failure in the middle of nowhere to months of trail abuse. Their go-to recommendation is molded every time.
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Mountain Soles & Outdoor Threads, a repair shop with 25+ years of experience, said flat out that waterproof zippers are “prone to failure,” while molded tooth versions “just last longer.” They also noted that Revelate Designs — one of the biggest names in bikepacking — has relied on molded tooth for years.
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Andy Schmidt, a veteran gear repairer in Portland, added that after years of replacing zippers, he avoids reverse coil (used on most coated zips) due to their “high failure rate.”
- Billy Sinkford, founder of MADE-the largest handmade bike show in Portland, Oregon, also states that the coating of waterproof zippers always tends to flake over time. For this reason, I sewed the zipper on with the coating in on his recent frame bag for the Thomson booth (so he thinks of me when he has to clean it out of of it).
Even those who love coated zippers admitted their limits. Some said they keep out dust and mud, and others give thanks for saving their phones in a downpour. But when it comes to longevity, the vast majority agree molded tooth wins.
My Take
I used #8 Uretek as my standard zipper for a long time. It hit a sweet spot between cost, smoothness, and strength. But that's changed - cost doubled over the last year, quality became inconsistent, and availability became unreliable.
The final push came from feedback. Not just from the pros above, from my own and friend's real world testing. I feel they glide better, and actually prefer the rugged unique look.
Moving forward, I'll be using #5 and #10 YKK molded tooth zippers as the new standard, with #10 Uretek offered as an upgrade option by request.
Final Thoughts
Molded tooth zippers aren't new to the scene but I'm excited for this change. Every component on every piece of gear I make is intentional and this is no different.
Let me know what you think in the comments.