[pct-l] seam sealing a taped-seam sil-nylon tarp/fly?

[Ron Moak]

Linda,

You should note that silicone coated nylon tent fly that has been seemed
taped is not the same as a pure silicone coated fly. The taped side of the
material is coated with polyurethane. This is because seam tape will not
stick to silicone. The non taped side will be the silicone coated side. 

My suggestion is to ignore the side with the seam tape. And apply a thin
coat of silicone seam sealer to the other side. Make sure to thoroughly
clean and dry the seam before applying the sealer. The silicone on silicone
sealing should create a bond that will last the life of your fly. 

Detailed directions on making and applying silicone sealer can be found at
(http://www.sixmoondesigns.com/support/seam.asp). 

Because of the nature of polyurethane, you cannot create a permanent bond.
As a result any efforts at sealing that side will need to be repeated at
some point. Nor can effectively you apply silicone to the polyurethane as it
will not adhere correctly.

Hope this helps.

Ron