Rewaterproofing silnylon options

Hi all. I appreciate the input in advance.

I was wondering if there are options for re-waterproofing a silnylon tent and if anyone has any experience? Do you just have to paint on a 50/50 or thinner solution of GE Silicon II and mineral spirits? Or are there some wash in-type solutions? Seems like a spray or a wash would be preferable for time and convenience.

Also, point of process: can I apply over the existing silicon layer? Have to clean the tent first? Use a rag and clean the underside of the tent fly with some mineral spirits and then paint with mixture? Or just throw the tent in the washer (front loader) with some mild detergent and then apply mixture?

Thanks for any insight.

Atsko, amongst others, make a spray for that.
http://www.atsko.com/products/waterproofing/silicone-water-guard.html
I used the McNett version in this clip..
http://www.youtube.com/user/francodarioli?feature=mhee#p/u/12/GBnkGIz9cco

They used to have a liquid version (1 gallon can) but cannot see that on their web site now.
I think that the liquid one is 100% silicone (like the GEII) highly diluted with mineral spirits.
I use something like a 1 to 2-3 dilution for seam sealing (1 part of silicone) so I would use something like 1 to 5 for reproofing.
If the stuff sack of your shelter is made from silnylon do a patch test on that.
BTW, there are less than 2 oz of silicone in those cans, so you do not need all that much to do the all tent.
I would just hose down the tent first. If really dirty than wash down with pure soap and water (the stuff you use for wool/down)
Franco

This product works well -->

http://www.atsko.com/shop/catalog/SILICONE-WATER-GUARD-12-fl-oz-aerosol-p-16174.html

I've seen it in our local hardware store and you can easily find it other places online (Amazon etc.)

One spray can is sufficient for any poncho or tent. Be sure to thoroughly wipe down the surface with a wet towel (and let dry) before applying. Spray on and wipe in well with a paper towel. Let dry. Repeat. Two coats will do wonders for restoring water repellency.

-H

It's really wonderful that experts like Henry and Franco of Tarptent take the trouble to come on here to contribute their knowledge. Thanks, Henry and Franco! I've bookmarked the spray in case I ever need it!

I would not call myself an expert but if I had to I would ask Henry...
Franco

Is that product what would be used for seam sealing a tent as well?

Not the spray.
The idea of seam sealing is to fill those tiny stitch holes not to coat them. (that is why diluted silicone works better)
The spray is strictly for coating.
Franco

Reply is much appreciated Henry and Franco!

Quick question:

Would you recommend applying the spray on the inside or outside of the tent (essentially on the fablic or silicone coated side)?

On the outside.
Silnylon is impregnated with silicone not coated. So at least in theory both sides should be the same
If one side (usually the underside) feels different , it is because it has a PU coating. In this case make sure that you always dry the fly well before you store it because PU can get mouldy and can also peel off.
Franco