nikwax waterproofing

It is doubtful that the Nikwax product will have any effect, since it is intended to be a water repellant and not a waterproofing, and it is intended to be absorbed into the fabric it is sprayed on. The silnylon will absorb very little if any of the stuff. The other option, of coating the silnylon with some variation of silicone caulking or Silnet, thinned or not, will probably add enough weight to the tarp that you may as well just go for a light polyurethane coated nylon tarp instead – or get spendy and go for a Cuben tarp.

Paul people who have used the mineral spirit thinned silicone treatment for their shelters report a weight gain of two to four ounces meaning that their treated silnylon shelter would still be lighter than or as light as a corresponding polyurethane coated nylon shelter of the same design. So if you already have a silynylon tarp and are concerned about misting the treatment would still make sense.

Take time to read the two threads and one article that I posted clickable links for earlier on in this thread. The weight gain issue and many other issues regarding the overall topic of misting is covered in the threads and the article. A little bit of background reading may help you in offering more insightful comments. I do not mean to discourage you from participating in this thread and any comments you have are certainly welcomed. I learned a lot from the two threads and the article and feel that others can as well.

Yes cuben would be awesome but costly.

Peace and trail grease, -Jeff

Hi Ben

> when you can easily roll up your tarptent without the fabric ballooning out
> — that's permeability right there
Well – unless the air is leaking out between the folds – which happens with my tent all the time.

Fwiiw, silnylon is often called 'zero porosity' in the context of parachutes and advertising blow-ups.

Cheers

Well thanks everyone for the discussions and links. I've definitely ruled out the nikwax solution. I'm pretty confident about doing Mr. Woods treatment( coating underside with diluted silicon). So anyone who has done this please tell me how it turned out and if it is real tacky or if the "grippiness" is a problem.
Thanks a ton.