my zipper broke

Yep.  Same thing happened on my Henry Shires Tarptent.  He talked me through the fix, and it has worked nicely.  I couldn’t help thinking that I should have known about this years ago!

Who is Gemini?

According to Gemini…

Gemini (AI): This is the name for a family of multimodal large language models developed by Google AI. It’s the technology that powers the conversational AI chatbot, also called Gemini, which was formerly known as Bard. This AI is designed to help with tasks like writing, planning, brainstorming, and can interact with various Google services.

I asked gemini and it said

“In Greek mythology, the constellation Gemini is associated with the twin brothers, Castor and Pollux. They are also known as the Dioscuri, which means “Sons of Zeus.”

Their story is a tale of a unique bond and brotherly love. They were born to Leda, the Queen of Sparta, but had different fathers. Castor was the mortal son of Leda’s husband, King Tyndareus, while Pollux was the immortal son of Zeus, who had seduced Leda while disguised as a swan.”

This might appeal to Nick because it is both a Greek god – Nick is into Greek stuff, and it’s a constellation – Nick is into taking star pictures.

I’m thinking maybe toothed zippers are less likely to do something like this.

After reading about the differences between a coil zipper and a tooth zipper, your thesis would make sense. I’ve probably had more tooth zippers fail, but they may just be more common.

Other than around the footbox, do you need a coil zipper on a sleeping bag?

No.

I think I’ll use toothed zippers for a while

I’ve used coil more in the past.  And had a few failures.

The right tooth zippers are less likely to do it, depending on the design. Coil is better if there are curves

interesting – that makes sense – thanks

I don’t think any of my zippers are curved so I think I’ll just use toothed zipper

Yeah I had both inner door zippers on a TarpTent Stratospire 2 fail on weeklong trip to Death Valley in January 2020.   Once back home, I tried squeezing the zipper sliders with pliers as discussed.  I just couldn’t get it dialed in, and I ended up ordering two new sliders from TarpTent and replacing the sliders.  This required making a small cut in the coil zipper where the slider stops in the “open” position, removing the existing slider, putting on the new slider, and the sewing the cuts in the coil zipper as a new “stop”.  It’s been working fine since!

https://zipperrescue.com/ has some good tutorials on the process as well as new zipper sliders to repair various items.

There are some other zipper products on Amazon that appear to be sliders that “clamp” onto the zipper coils without requiring you to cut the zipper to remove the old slider and put on the new one, etc.  ZSlideOn is one, FixNZip is another.  They’re meant to be a temporary fix, but I haven’t ordered any of them or tried them.  They seem like they could be a good addition to field repair kit if they actually work.

After reading this thread, I feel I need to learn how to fix zipper problems in the field.

After a really long day last year ( I hiked 14 miles in non-stop rain ) in Yellowstone, I got to camp, put up my tent and upon closing the outer tent, the zipper had gotten stuck of the outer fly. It was still raining and I couldn’t fully close my outer door.

My spirit was already low and this really made me hit rock bottom. It was low 40’s and going to get colder over night. I had very little energy to deal with this. I messed with it, kind of pulling on the fabric with one hand while trying to pull on the zipper with the other and I eventually was able to get it fixed. It took about 5 minutes of messing with it.

This was a slingfin portal 2 by the way. Probably doesn’t matter except it was a silnylon which I knew was more durable and stretchy than other fabrics. Which played into my strategy of how to fix the problem.

Anyways, if Ryan reads this, I think it would be awesome to have a master class on fixing gear in the field. This may be trivial to most people on this site, but I would like to hear how more experienced people do it. Off the top of my head, all I can think of is how to fix issues with various fabrics and zippers.

You could bring some safety pins

Needle and thread

Joey G – I have a SlingFin CrossBow 2.  Don’t all the SlingFin tents have redundant sliders in case the first one fails?

Of course, that doesn’t help if you damage the zipper coil itself!

I think the redundant zipper sliders is a REALLY GOOD idea on tents with these small #5 zippers that can fail easily.  It’s a few extra grams of weight for a decent amount of extra reliability/redundancy.

Both synthetic coil and metal, or plastic, tooth zippers will fail in the field, as I know in both tents (Tarptent Notch) and sleeping bags (Zpacks), often because of grit. Blown sand esp. will find a way into the zippers and splay the sliders. When this happened to the tent, both inner and outer have failed over a 12 year period of heavy use, occasionally involving wind and sand, its game over. Since I don’t bring pliers to make a field repair by squeezing the zipper pull, this failure ends the trip unless the weather is such that I don’t need a tent or can use a partial tent (one side still working) as a mini-tarp. Henry Shires has fixed these failures for me by putting in new zipper pulls as already mentioned in this thread as a DIY fix.

With a failed zip on a sleeping bag its not so serious unless its quite cold. I force the failed zipper pull about 1/2 way up the bag’s coil so there’s an open area below and above, and I can clip the bag closed at the top. So then I use the bag as a quilt, with the quasi-open zipper under me. (Quilts generally don’t have zippers, just clips, which is something like this.) This makes getting out/in at night a bit challenging but manageable until I can replace the zipper pull.

Unless teeth are broken in the zipper coil/strand, there’s no need to replace that. Its the pull that has splayed.