How much ,if any, does sil-nylon lose its waterproof characteristics over time. I have an older TT Rainbow, first or second year of manufacture. It seemed to be either misting or heavy condensation the last time I used it. This was in the PNW near water and kind of cold rain conditions. It was seam sealed soon after purchase. I've used the tent a lot over the years but it has always been taken care of; dried after each use, not left all day in the sun, etc. I'm thinking of selling it (replaced with a SMD Starscape) but I don't want to put a bad tent out there. Thanks.

Sound like it's probably time for some coating reconditioning. When we see older, well used tents come back that no longer bead water we use this stuff

http://www.amazon.com/Silicone-Water-Guard-Aero-12oz/dp/B0001FYL2M

A couple of coats of Water Guard applied to a clean surface--set up the Rainbow , spray on and thoroughly wipe in with a paper towel, let dry, repeat--will do wonders for water repellency.

-H

Henry,
Thanks for the good advice. As soon as we get a dry day I will try that.

I have also read about diy silnylon reconditioning using the clear silicon caulk mixed with mineral spirits and a brush. It raises the mm coating rating by a factor of 10 and eliminates the misting, but also may add some unwanted ounces due to the coating. You may be able to dilute the recipe.

"I have also read about diy silnylon reconditioning using the clear silicon caulk mixed with mineral spirits and a brush'

That is (I think...) what that Atsko spray Henry mentioned is all about.
The spray is ready to use and very easy to apply HOWEVER do not spray it too close to the fabric.
(read the instructions)
If you want to try to do it yourself , aim for a very high dilution, thinner again than for the consistency you use when seam sealing.
So VERY runny...
Here is a video clip on how that spray works :
http://www.youtube.com/watch?v=GBnkGIz9c...mp;feature=plcp
The one I used has a different brand on it but probably is the same stuff.
Franco

+1 for Henry's recommendation of Atsko silicone Water-Guard. I refresh my Hennessy flies and other silnylon items from time-to-time with it.

In addition to finding it at Amazon.com, I've bought it directly from Atsko.com when I also wanted their water-based products. The least expensive source for the silicone Water-Guard might be a local retailer like WalMart or Sports Authority.

CamperMom