COATING SILNYLON TO INCREASE HYDROSTATIC HEAD AND DURABILITY:
I have coated a few of my Tarptent tents to make them more waterproof. When I owned my first TT tent, the Contrail, there were reports that its fly would "mist" inside in a driving rain. This was a single wall tent, BTW. Never had the problem, even in a Yosemite thunderstorm, but being a belt-and-suspenders type I followed the recipe from a BPL post on the topic and coated the fly in the following manner:
MATERIALS:
-> one caulk tube of GE clear silicone caulk
-> one pint of odorless mineral spirits
-> one 6" wide small paint roller tray, roller and lowest knap roller brush
-> one empty pint jar and lid
-> roll of heavy duty paper "shop towels"
-> pairs of Nitrile gloves
PROCEDURE:
-> by volume place 5 parts odorless mineral spirits and 1 part silicone caulk into the pint jar, cap and shake well to thoroughly mix (The 5:1 ratio seems to work best.)
-> pour some of the the mix into the small roller pan and thoroughly but lightly coat the roller
-> roll onto tautly pitched silnylon tent exterior in approximately 12" x 12" areas (15 cm. x 15 cm. ?)
-> immediately wipe down with shop towels to remove excess mix
-> continue coating tent with slight overlap of coated areas - use foam brush for irregular areas you can to coat with the roller
->re-shake mix every 10 minutes
*-> for tent floor (exterior) Place tent over card table so table fits inside with the floor exterior facing up.
-> Roll on mix and wipe down as before. Move floor over card table as necessary to have flat application surface.
-> Second coat may be applied the following day it 1st coat is totally dry.
CLEANUP-> mineral spirits
I did this to my later Moment DW and SCARP 2 tents not knowing Henry Shires had begun making them with an increased coating thickness (higher hydrostatic head) and that coating the flys was now unnecessary. Still coating the floors is a good idea and obviates the need to take a ground cloth along.
Eric B