Reducing porosity

[batchoy]

Having had a conversation with C2lln over the weekend with regard to reducing the (air) porosity of fabrics which have either lost their coating or never had it in the first place I have been reading around various related forums.

One of the contributors to a paragliding forum has done some rough and ready measured tests using readily available (in the USA) treatments:

Coating	Porosity before coating	Porosity after coating
Turtle Wax F21 Super Protectant	52 seconds	112 seconds
Scotch Guard	81 seconds	140 seconds
303 Aerospace Protectant	74 seconds	253 seconds
Dollar Tree Upholstery Protectant	85 seconds	151 seconds

What he doesn't mention is the durability of the treatments but the best performing treatment 303 Aerospace Protectant is available in the UK and might be worth testing polishyourcar.co.uk/303-aerospace-protectant-32oz.html

[jelv]

What about reproofing spray designed for tents? Given the summer we've had having kites that resist the water when it's raining would be a considerable advantage! (Says he who spent a couple of hours drying teddy after the Brighton festival)

[batchoy]

Tent waterproofing tends not to work. The chemicals used coat the fibres in the fabric but don't fill the gaps in the weave, hence the fabric remains porous to air and water vapour but repels water in its liquid form. Hence why Scotch Guard performs badly in the tests

[greenman]

£25.00 for a small bottle would get a tad expensive when you are trying to wind proof a Killer Whale!!!
We are generally talking about flexible polymers here.
If anyone has got any spare porous material that they don't want then I will have a word with our lab and see if we can create something that will work and be a darn sight cheaper.

[batchoy]

I have not been able to get any details on the materials in the 330 Aerospace product, and the MSDS gives no clue but I would guess that we are, as you suggest in the realms of flexible polymers in solution in water rather than solvent.

If you want porous material I have both raw and parachute ripstop.