Waterproof zippers, how well do they work?

I've used a waterproof zipper on a pack hip belt pocket I made. It was VX07 with a waterproof zipper. I was in a heavy sustained downpour. I thought that I would undoubtedly have water in the pocket by the end of the day. The VX07 was saturated on the face fabric. However, when I reached camp, everything was bone dry, including my phone (I use it for pictures). So definitely a positive experience for me.

They work great. I find them much easier to install then regular zippers, because of the coating they are a little stiffer and easier to sew. I find them much easier to install the pulls on as well. I would say the only negative thing about them is the price increase over regular zippers.

Chris and Michael,

Are you referring to the coil zippers with the tape-like layer of urethane on top? I haven't actually worn one of this type out, but I have read complaints about their durability for high-use applications. The slider abrades the rubbery layer on top, apparently. It has been claimed that tightly mating plastic tooth zippers (like the RiRi Aquazip) are equally waterproof but more durable (although much more expensive). I can't provide any evidence for or against these arguments, just thought I would pass them along.

Hi Dave

They can be a real drag to do up … especially in the cold.
Meant literally.

Cheers

How about on a tarp/tent?

Replace the zipper and flap on a shelter with a rubber coated zipper?

CF water resistance, the RIRI's are certainly meant to be notably more water resistant than the 'standard' YKK things – they've been starting to crop up in a few high end waterproof jackets in recent times. Mind you YKK seem to have some sort of actually waterproof zipper now (the aquaseal).
(Brief description of both at the top here: http://www.phdesigns.co.uk/techfab.php? , although other people using them too.).

How relevant that is if they're not going to be under stress I don't know.

I will not buy any piece of gear that has a urethane-coated zip. From my experience trying things on and using loaner gear (jacket, backpack, accessory pocket), they are a severe hassle. I've usually needed to use both hands to operate the zipper. I can't imagine using one for a very long zipper on a tent. Flaps are nice, if constructed to avoid snagging. No experience with RiRi.

Hi Dave

> How about on a tarp/tent?
Well, that's the funny thing. I use ordinary plastic coil-coil #3 zips on my summer and winter tents. They last for … well, I have never had to replace one, anyhow.
I gave the fabric tape a good spray with DWR at the start, and they haven't leaked noticeably yet. Yes, I do have a silnylon storm flap over the zip – sometimes it does even cover the zip!
Works for me.

Cheers

I have used mid shaped tarps with no flap and no DWR spray along the Washington coast
and didn't notice any drips. Maybe it is just the perception that a leak will be a problem? Maybe too it is in snowy/rime conditions that a flap is needed to prevent the
zipper from freezing even with a resistant zipper tape.

Same experience David

I use regular zippers, no flap, and don't seal seams either in Oregon and Washington and never noticed any drips. Many times with heavy rain and wind.

However, I don't have anything directly underneath the zipper, but you should do that anyway because when you open the zipper to get in and out water will drip down there.

And my rain jacket has a regular zipper with no flap. With coil zippers the fabric of the zipper tape almost completed blocks the opening, but this is breathable fabric. There is probably a little rain getting through, but I get way more perspiration than that so it's not significant.

One time I had an annoying drip where I sewed on a velcro strip to hold the door open. That's the only thing I worry about waterproofing. Use silicone.

Try using McNett Zip Tech™ Zipper Lubricant on your waterproof zippers and you will “feel” a difference in sliding both in cold and warm environments.

ZipTech

So if I haven't gone completely brain dead, as I understand, a couple of you use regular ol' zippers with no flap and no coating on the zipper tape on shelters….and have no leakage during rain?

What about the zipper tape absorbing and holding water? Seems an invitation for mildew if one had to pack up before it could dry…especially for kayakers where it would be packed in a waterproof bag between camps. Or, am I missing something?

I think if it's raining, regardless of flap or waterproofness, the zipper tape and all your gear will get a little damp.

Mildew normally takes days.

Mainly you need to dry things out good between trips.

If you're on a weeks long Amazon Kayak trip then maybe you need to be more dillegent?

Yeah, that makes sense.

I like the idea of using a regular zipper over a waterproof zip in a shelter door just for the ease of use (less drag, less force needed to zip & unzip). Prior to reading the experiences here, it never occurred to me that a regular zip would suffice though.

The waterproof zipper on my kayak deck bag (not sure of the brand) worked great for a while, but since I open and close it often to get my camera out it gets a workout. After a relatively short time the waterproofing parts wore out and folded back, and now it's just a regular zipper with not even a rain flap.

On the other hand the waterproof zipper on my Kokatat drysuit is great, and I understand they last nearly forever. But they are really heavy and not suited for backpacking gear.

How about wind resistance? I've noticed several light weight windshirt and rain jackets that use a waterproof zipper in place of a zipper baffle. I know from experience that a normal zipper w/o a baffle lets a lot of wind through, so well how does a waterproof zipper block wind? My super NOT ultra light marmot jacket is double baffled, and it's freaking awesome in cold wind. With all the "hatches battened down" (all drawstrings pulled tight) absolutely nothing gets thorough. I can't imagine SUL jackets would match that performance.

I've used waterproof zippers on a couple of previous projects, only because I thought I was supposed to. I was following other myog project guides, and they used waterproof zippers and I followed suit. I just purchased a bunch more for a 'mid project that's underway, so I guess I'll find out how well it works on something bigger. I'll be sure to get some of that zipper lube to increase its life.

BM

With coil zippers, the zipper tape almost closes the gap

The zipper tape isn't real windproof, but I sew the fabric pretty close to the zipper teeth so there isn't much of a gap

I've never really noticed it being cold where the zipper is

Darn, this would get posted after I ordered (and received) my first-ever uretek zippers for a project ("Parcho" jacket)… Oh, well, I'll get a chance to verify your negative reviews of them :)

"The zipper tape isn't real windproof, but I sew the fabric pretty close to the zipper teeth so there isn't much of a gap"

Thanks for the additional info. I understand what you're saying here but not the following:

"With coil zippers, the zipper tape almost closes the gap"

Could you explain?

Front and back of coil zipper

You can see on the back side how the zipper tape almost totally closes the gap.

The zipper pull goes over the tape.

All coil zippers are the same.

This isn't a very good picture (either) but I try to get the fabric as close to the zipper teeth as possible. If it overlaps the teeth then it can snag, but as long as it doesn't, it's okay

"With coil zippers, the zipper tape almost closes the gap

The zipper tape isn't real windproof, but I sew the fabric pretty close to the zipper teeth so there isn't much of a gap

I've never really noticed it being cold where the zipper is"

I just now took a careful look, and apparently my jackets have "tooth" zippers, which would explain the need for the baffles and the huge draft on the jackets w/o one.

And just to go on record- I purchased some #5 uretek stuff for some bike-packing bags I made, and I have not noticed them to be difficult to open or close at all. They are short zippers though. I'll be putting about a 5' piece on a tent here in a little while, and I'll be sure to post how it works out.

The only part that's a bit frustrating is how much extra $$ I spent on that zipper if a normal one would have been adequate.

BM

Ahhh…got ya! I looked at some of my zippers before posting but I didn't even think to look at the back side. Doh!

Thanks for the explanation and pics. Appreciated!