#8 Overkill?

I remember in 1980-1981, after the Mount Saint Helens eruption, REI tested a bunch of zippers (jackets? tents?) by smearing them with a slurry of water and MSH ash.  Some failed in just a couple of cycles.  Others lasted a long time.  Point being: some zippers are more tolerant of grit than others.  And that some testing of that sort has been done.

I like Jerry’s idea of drawstrings, but how about some closely spaced tiny loops?  Then lacing it up with 100-pound test braided line in pinch if the zipper failed.  Like a football is laced up, or a shoe.

Is there some lace trim or piping that has frequent loops in it that could be stitched in when the zipper is installed as a “belt&suspenders” contingency?

failing tent zippers are my pet peeve.** for two ounces I’d upgrade for sure. Because zips always fail just as the storm is coming in.

**which is why I always liked the idea of a velcro system,although I’ve never had one.

Amish?

#8 is pretty massive – I haven’t used one of those in about 30 years, even on a pack. I’d go with #5 and do a little silicone spray now and then to clean and lube. Should last as long as the tent.

For what it is worth, 3 feet of #8 YKK–if that is what you are using–plus the slider weighs ~0.7 oz.  Depending on how much velcro (erm, hook and loop) that you are removing, it might even be lighter with the #8.