A while back, I pulled our old daypack out of its storage place and found it was totally salt-encrusted and water stained. None of the zippers would budge. That wasn’t going to work.
A couple years ago we’d won a new one and this one got thrown under the bed and forgotten; now we wanted to use both. Oops! I was afraid it was just a goner.
Figuring that I had nothing to lose, I soaked the daypack in some hot vinegar water for an hour, and that got the two largest of the three zippers working.
I used a 5 gallon bucket and put almost a quart of cider vinegar* in it, then added boiling water (I’m guessing about 3 gallons — it’s not rocket science) and then added the daypack and used our grill tongs to push it down into the water. A couple of times during that soak time I used the tongs to swish things around.
On the third zipper, Dave squirted straight vinegar into the zip pull and then used pliers to pull. Now it works too!
Figuring that the daypack was already totally wet, I ran it through the washer on gentle then dried it in the dryer (normal heat). Looks great and all works perfectly — I just put a bit of ZipCare on the zippers to keep it from having problems again. Woo-hoo!
*Cider vinegar is more acidic than distilled white vinegar, making it a better choice for dissolving salt encrustation.