Waterproofing Parachute silk test results.

[Bucephalas]

I was seeking advice from the forum and from Mr.Google a while back trying to establish if it was possible to waterproof parachute material (silk Nylon?).

The general consensus was that it wasn't possible, mainly due to the type of fabric and weave etc.
Well yesterday I performed a test with the material and can report that you can in fact successfully waterproof it.

I cut two 1mtr square pieces and treated one with Fabsil and left the other untreated.
Todays rain gave me the perfect opportunity to test out the two.

The untreated one did allow the rain to run off it when "pitched" at an angle, but droplets were evident on the inside after prolonged exposure. When water was applied from a height (so under pressure) then the water did permeate the fabric causing a fine mist of water.

The treated fabric allowed no rain through at all and even when under pressure showed no misting or leaking. I created a well and poured 2 ltrs (2 kgs) of water into the well and water did drip through the fabric at a rate of around one droplet every 10 seconds or so. The next time I checked there was about a litre of water in the well but all dripping had stopped.
Not a necessary test as when used for a tarp it would always be pitched at an angle, but an interesting test nonetheless.

Just thought I'd share my result for anyone posing the same question in the distant future.

 

[Harvestman]

Nice one. that's the sort of practical information people want.

Good on you for doing the tests for yourself.

 

[tommy the cat]

Good stuff!

 

[Bucephalas]

I had to do it. I have more parachute material than I care to mention and there's only so many hammocks I can make.
Now I've added tarps, ground sheets, stuff bags and all sorts to the list.

 

[redandshane]

Oh well done Bigcephallus
Useful stuff then?
Cant wait to enjoy what your skills can provide
Nice one matey

 

[treadlightly]

Well done for doing the experiment and thanks for taking the trouble to post it. Very pertinent for me as I've recently put up a steep sided tipi with a parachute as the cover and I'm in the process of working how water proof/resistant it will be. Apparently a few smoky fires help the water resistance and there will be no shortage of those.

 

[Midnitehound]

Well done for doing the experiment and thanks for taking the trouble to post it. Very pertinent for me as I've recently put up a steep sided tipi with a parachute as the cover and I'm in the process of working how water proof/resistant it will be. Apparently a few smoky fires help the water resistance and there will be no shortage of those.

I wonder if this silnylon approach would work on a parachute as well as it does when making a 1.1 ripstop tarp.

http://www.youtube.com/watch?v=-UTZPllgqSc

 

[TurboGirl]

Ohhh you star! We're doing one for the NorthWood communal soon and I was disheartened to hear 'it isn't possible'... not that this was going to deter me after a memorable rainy night under an untreated one, the misting was absolutely incredible and NOTHING I do to it could possibly be worse!! The White Rose guys have just done one too with proper fabsil although we might use a 3 or 4:1 white spirit to silicone sealant DIY mix- they used IRO 10ltr which costs about £60 and homemade should halve that. I've done a medium tarp before but it was a PIA to mix.

Would you mind if I post up some pics of my own chute to ask about preparation? It has its pre launch bag which I'm thinking of making into a top hat cover for the fire hole and I was wondering if the lower section, which is attached to the mid line all round with paracord, should be released. As always, the pictures make more sense than I do

I've just read that some folks do it with thompsons water seal at half the price of fabsil, which would save the dreaded mixing... but we used to use it on military tilts and thompsons reckoned they'd changed the formula a few years ago and it would eat fabric? Anyone any experience with that?

 

[Teepee]

I've had the same results. Some doors on one of my tarps is 1.0 oz unfinished parachute nylon treated in TX direct. They hold a lot of water before they start slowly dripping.

I'm guessing the doors have been treated 4 years ago and still as good as when first did them.

@Sally. The new Thompsons is water based, I wouldn't trust it on fabric. Best stick to Fabsil, it's got more UV blocker in it too so will make the kit last longer. (Nylon is awful for suffering UV damage).

 

[TurboGirl]

Thanks Pete, thats great advice I'd not considered the UV blocking additive. Good point My chute (as opposed to the NW communal, I've not seen it or remember the measurements) will be up prob 6x a year, weekends only so I can practice on that one and UV and performance is not so much an issue. I need to go economy and might as well use this as a test for the important one, it might be an option to fabsil on the one lots of folks are contributing to Its to be a group decision as we're all paying, I think

So two questions here- Is there any advantage or disadvantage to removing the white webbing at the chute edge? I thought it'd save on proofing and weight and if left on, be a potential problem netting drunken bushcrafters (EDIT- on reflection, I think I might leave the first set of holes both along the tieouts so they're visible and around the circumference to hang lanterns, flora at celebrations )

Secondly should I remove the paracord between the outer edges and the loops at the midline to prevent puddling of rainwater in the edges? Are there any other suggested shaping alterations to a chute?

I was thinking of converting the fabric area of the deploy bag into a loose cover for the smoke hole? Is there reasons why not if its suspended from the central fixing point and left loose at the edges so it will let out some smoke but stop the majority of rainfall??

Thank you so much for any advice

 

[TurboGirl]

I've heard a bit more about the thompsons Water Seal, so like Pete says it's water based now and the problem is it leaves water marks in tilt canvas, a big no-no in the military display scene but no trouble here-in fact it'd add to the camoflage effect... Most tempting of all, it requires no mixing and goes a LOT further so 5ltr @ £17 would do the whole 6m radius chute

Any experience of it on chutes lads or lasses? Oh and apologies to the OP for using his thread as a notebook and question hunt

 

[mousey]

A while a go I bought this 5 litre tub of fabsil £23 which I thought was quite reasonable.

http://www.amazon.co.uk/gp/product/B000XY27KE/ref=oh_details_o07_s00_i00?ie=UTF8&psc=1



When I finish with it I can see a nice hobo stove coming from the container....

 

[Bucephalas]

I had heard that Fabsil made changes to its product a while back.
Fabsil is great, but expensive on the whole. If a group are chipping in then just get a big bucket and dip in fabsil.

 

[TurboGirl]

Yup, that's the groups plan, they're aiming to do it at their end June meet and I have Thompson for mine to compare and for cheapness. Gotta pick my timing carefully to git R dun though

 

[ged]

... any other suggested shaping alterations to a chute?

In my experience the hole in the 'chute as used for jumping out of aircraft is far too small for letting smoke out from a fire.

I was thinking of converting the fabric area of the deploy bag into a loose cover for the smoke hole? Is there reasons why not if its suspended from the central fixing point and left loose at the edges so it will let out some smoke but stop the majority of rainfall??

Just sit somewhere else.