Reverse zipper for footbox
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Brad Groves
(4quietwoods) - MLife

Locale: Michigan
Reverse zipper for footbox on 06/09/2009 14:55:12 MDT Print View

Okay-

I'm trying to install a second zipper pull onto my last bag; I can put a second pull on with no problems, but only if it's running in the same direction as the first pull. In other words, I want the bag to unzip from the foot toward the head, just like any other sleeping bag. I can sort of get the zipper pull just seated on the coils situated "backwards," but can't get the pull onto the coils more than half way. (It stops going onto the zipper at the point where the "skinny" part of the pull meets the tab mouth opening up.

Suggestions? Is this something a mere mortal can do with continuous zip? Or do you need some sort of special reverse-oriented zipper pull?

Like I said at the beginning, I can put a second pull on, but it won't keep the zipper shut between the two pulls. So I need to be able to mount one of the zipper pulls backwards...

Brad

Tim Marshall
(MarshLaw303) - MLife

Locale: Minnesota
Re: Reverse zipper for footbox on 06/09/2009 15:19:43 MDT Print View

if you can only add the zipper from one end of the tape one of the pulls (the 1st one) must go on backwards. However if you can add pulls from both sides then add one at the bottom and one at the top and they will be facing each other when you're done. is that what you mean?

-Tim

Brad Groves
(4quietwoods) - MLife

Locale: Michigan
Re: Re: Reverse zipper for footbox on 06/09/2009 15:36:48 MDT Print View

Hey, Tim-
Good way of phrasing it... What I mean is I need the zippers facing away from each other. I can add from either end still. Thanks!

Brad

Tim Marshall
(MarshLaw303) - MLife

Locale: Minnesota
Re: Re: Re: Reverse zipper for footbox on 06/09/2009 18:20:22 MDT Print View

one must be added in reverse then. No other way, and no easy way.

-Tim

Brad Groves
(4quietwoods) - MLife

Locale: Michigan
Re: Reverse zipper for footbox on 06/09/2009 18:53:40 MDT Print View

Bah! Well, thanks Tim. I guess I just have one question, then:

is it possible with a standard slider?

Brad

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Reverse zipper for footbox on 06/09/2009 20:47:57 MDT Print View

Yes, BUT ... it requires a huge leap of faith and does NOT necessarily allow you to separate the two halves later. It doe NOT necessarily make a separable jacket-type zip.

Method 1:

You have to start with the two parts of the zip fully separated. You feed the first slider on with the flare facing forwards, and try to get enough through it that you can start to run it down the length.

Then you find you are one tooth out in the alignment and start all over again.

Eventually, when you have the first one in place, you thread the second one on going backwards. As it goes on it opens the zip up again.

This can only be done if the top end of the zip has not stoppers on it. Yes, I have done it that way, although it was easier to load one slider on from each end.

Now, this may or may not let you separate the two halves afterwards. That depends on the end-bit on the zip. So ...

Method 2:

If the above method does allow full separation, then a far easier way is to slide the two sliders onto one zip part, run them down to the bottom end, and then to poke the other part in, just as you would with a separable jacket zip.

However, this requires that you have the right sort of ending on the zip, which is extremely unlikely unless it was a separable zip in the first pace. In which case you probably would not be asking.

Cheers

Edited by rcaffin on 06/09/2009 20:50:15 MDT.

Bill Fornshell
(bfornshell) - MLife

Locale: Southern Texas
Reverse zipper for footbox on 06/09/2009 21:24:51 MDT Print View

Hi,

Why don't you try a 2-way separating zipper

?

Brad Groves
(4quietwoods) - MLife

Locale: Michigan
Re: Reverse zipper for footbox on 06/10/2009 10:07:12 MDT Print View

Hi-
The zipper's already sewn into the bag, and I don't want to rip it out and sew in a new one. I don't really care if the zipper separates; however, from what I've found online it might be the only way to get a zipper that goes in opposing directions. Unfortunately, I haven't found any #3 zippers that function like this. Everything I've found has been #5, which frankly is overkill for a sleeping bag. Thru-hiker, questoutfitters, therainshed, and seattlefabrics are all no-go for a #3 coil zip of this nature.

I'm pretty sure that the existing zipper can't be made to work as I hoped. Perhaps a fancy zipper pull would enable the possibility, but I haven't found one yet. I might just have to leave this one as-is; the zipper is functionally shorter than I anticipated (meaning, I thought it would be easier to stick my feet out the end), and a one-way zip might just have to be okay for this one. However, for my next bag I would like a #3 coil 2-way zip (same exact style you'd find on virtually any commercial bag, allowing one to ventilate feet while keeping the zipper closed between the upper and lower zipper pulls). If anyone has seen these somewhere, please let me know!

Thanks!

Lance Marshall
(Lancem) - F - MLife

Locale: Oregon
Reverse zipper for footbox on 06/10/2009 12:31:50 MDT Print View

Brad, is this what you are trying to do?

zipper1

Assuming I understand the problem correctly, here is how to solve it:

Open up the end of the zipper an inch or two and trim one side back two or three coils(THIS IS THE KEY).
zipper2

Run the first pull back to the end to reclose the coil.

zipper3

Feed the second zipper pull onto the end. Having one side longer allows you the 'foothold' and leverage to separate the ends "at the point where the "skinny" part of the pull meets the tab mouth opening up".
zipper4

Gently pull apart and then through. Done.

zipper4

Edited by Lancem on 06/11/2009 18:52:37 MDT.

Brad Groves
(4quietwoods) - MLife

Locale: Michigan
Re: Reverse zipper for footbox on 06/10/2009 15:39:03 MDT Print View

Lance, you're so good it must be a dream... we'll just have to call you the zipper king! That's exactly what I'm trying to do. I'm going over to a friend's place right now and I'll see if a third and fourth hand can help me through that. My initial "response" is that it seems like I'm doing the same thing you are... I'll attach a couple photos of a play zipper I'm practicing on.

Top view of zipper:
top view zipper

Bottom view of zipper:
bottom view zipper

There are three coils on the "long" end. Maybe they're somehow chewed up?

Lance Marshall
(Lancem) - F - MLife

Locale: Oregon
Reverse zipper for footbox on 06/10/2009 16:10:54 MDT Print View

Brad, Thanks for the praise!

A few more hints:

Heat seal the fabric portion of the zipper. The fabric will melt and seal before the coil. Practice on a scrap piece.

It doesn't take much force. I didn't have to tie out the tabs to something solid or hold them in my teeth. It just takes two hands, unlike starting the first pull.

Don't force the zipper tight against the 'separator' inside the flared end of the zipper pull. That will only push the coils together and make the task more difficult.

As the long side of the zipper comes thru the second zipper pull, bend the long side of the zipper away from the centerline. This should 'open up' the coils and allow the two halfs to separate as they go thru the flared end of the pull. Do the same with the short side.
Zipper pic
zipper 8

Hope you have success.

Edited by Lancem on 05/15/2012 19:11:51 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Reverse zipper for footbox on 06/10/2009 16:31:36 MDT Print View

Hi Brad and Lance

Yep, agree 100%.
I don't unbalance the ends. Instead I mount the zip upright in a little bench vise (gently!), push the second slider down gently onto it and prise the two coils apart inside it with two large needles. The first time is always fiddly. By the third or fourth go it takes but seconds.

I think OWFINC can supply both sliders (single and double-sided) and continuous chain #3 zipper stuff. That's where i got mine.

Cheers

Brad Groves
(4quietwoods) - MLife

Locale: Michigan
Re: Reverse zipper for footbox on 06/10/2009 19:50:29 MDT Print View

YES!

Success! Thanks!

Between my friend, his girlfriend and I we had 25 years of collegiate education jiggling the blasted zipper tab around... but we (actually, my friend) got it on. In his words, it's a bit like trying to get a bolt through several pieces; it required a bit of jiggling to get things to settle into place.

Thanks again!

Brad