Waterproofing

[Colin]

Does anyone have any experience of waterproofing a Rev sail ? the reason for the question is this, it is now Autumn/Winter in the UK and it tend's to be a bit wet and after the sail has been laid on wet grass for a while or flown in the rain/damp condition's it get's heavier through water absorption and I was wondering if treating it with the type of spray on water treatment used to waterproof tent's or silcone spray would be beneficial, it may also help to shed water if the kite is flown into the sea or rivers etc ? this is not to much of an issue in the Summer if you get caught out by a shower of rain as the sail dry's fairly quickly when flown in warm air, unfortunatley we won't be having any warm air for a while in the Uk.

[johnnmitchell]

A new polyester sail tends to repel water quite well. Just make sure you shake it off and run a towel across it before storing it away.

However if you leave the sail flat on the ground in the rain it will start to absorb water. Try keeping the sail upright so that the water tends run off.

Older polyester sails that have seen a lot of use, tend to loose there water repellent coating and will absorb some water quicker.

Now nylon sails(pre-1998) will tend to absorb water earlier in their age and get a bit heavier then polyester sails.

I personally, would not want to put a extra water repellent on my sail.

[awindofchange]

You could try Nik-wax. We use that on older foils when they get so warn out that they are very porous. I am with John though, not sure if I would want to add the extra weight on the sail...just air it out in a couple minutes before you store it away.

[pwmeek]

In general, polyester repels water and attracts grease and oil. You don't want to put on any coating or water repellent that is oil-based, as it will be very hard to remove. You also want to be careful to avoid contact with anything oily, as it will add weight to the sail. I would accept any weight gain from atmospheric moisture and allow it to evaporate when the sail is in a dry environment. Adding weight with oil or any other water-proofing is more or less permanent.

Nylon will absorb quite a bit of water (and shrink when it does). It also takes quite a while for the nylon to release that moisture. For a nylon sail, adding a water-proofing might be worthwhile.

If the sail comes with some kind of air barrier, it might be worthwhile to renew it if it begins letting air through, as that will keep the light-air performance up to snuff. Just don't add weight for a short term benefit.

Edited November 21, 2010 by --Pete