I have reservations on treating silnylon. I tried the stripe thing and it didn’t work after a while because it got dusted up and held on to dirt. This would probably be worse by doing the whole floor. Untreated silnylon (and spinnaker) is so nice and easy to clean up--- by just shaking out.
I think there are lighter weight methods to misting and floor robustness:
1. Let the tarp/canopy be; I don’t know about this misting problem. I’ve been in my silnylon tarptents for 8 hours in hard thunderstorms—several times. I’ve felt no misting. But I may have excellent quality silnylon in my tents. Or if it did mist, I could not tell from the actual humidity. The important thing is, my bag or clothes never got damp/wet.
2. Now a wet ground will soak through where your butt is. However, GG’s polycro cloth http://www.gossamergear.com/cgi-bin/gossamergear/polycryo_ground_cloth.html
solves this at a lighter weight (1.5oz) with a bonus of multi use:
a. use to take afternoon nap on
b. greatly increases puncture protection on the tent--- better than the sealant treatment.
c. greatly increases the floor waterproofness--- better than the sealant treatment
d. takes the dirt stain hit before the tent does.
e. easier to replace the cloth than the tent floor
f. use to layout and organize backpack items
3. For sliding sleeping pads, use a 12”x12” cupboard liner. This weighs <1oz. This worked great with my 3/4 Prolite 4.
4. Or for sliding sleeping pads, buy the new NeoAir. Now that grabs silnylon and stays put on a slight slope!
Even after the treatment, Jim recommends a ground cloth: “Even with this treatment, you still may elect to use a ground cloth under your tent floor, if only to help keep it clean.”
Anyway, just some more thoughts to think about.