Sealing Ram Air Kites with Dissolved Silicone

[lightandfrost]

Light and Frost(L&F) ran some tests on sealing Ram-air Kites with Silicone dissolved in a solvent.

Sealing a kites' external surface would prevent loss of internal air pressure, prevent water entry when on the water and most important, prevent Ozone damage caused by UV radiation.

Several sites suggested approx 150 grams of clear silicone be dissolved in Acetone. DO NOT USE ACETONE!!! Silicone does not dissolve in Acetone and falls to the bottom becoming softer but not actually dissolved. Some sites pour the softened silicone into another container and then apply but that did not work either.

Next we tried "White Spirit." This worked very very well. Tubes of clear Silicone are approximately 300 grams. Half a tube was mixed with 1 liter. The silicone easily dissolved in white spirit when stirred and application with a wide brush to the kite surface was very easy. The White Spirit evaporated leaving a thin film of silicone embedded in the cloth

If you only want to seal all seams on both sides of a ram air, 1 liter completed a 10 meter ram air with some left over. The complete kite surface might require 3 liters or more.

[tomato]

i was thinking to try that on older LEI kite. Does anyone know if white spirit has an effect on PU bladders?

[merl]

Plenty of info from on old threads; marine goop dissolved in toluene or similar (pretty nasty stuff btw) seems like the best-performing option.

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Who are light & frost?

[Herman]

I have followed the threads on recoating with interest but decided not to pursue it as the recommended pu goo dissolved in toluene is too unappealing to work with imho.

However if white spirit works with silicone based goo on an old pu coat this could actually be a game changer for me assuming the recoat stays put for a reasonable amount of time.

[I am guessing this would preclude simple spinnaker tape repairs as I doubt that tape would stick to the silicone etc but that maybe a small price to pay.]

I would be interested to know what the original coating was or, what kites were used in the trial and which silicone goo works?

[evan]

Who are light & frost?

Someone with multiple personality disorder who likes to talk about himself in 3rd person


But wait, is he talking about the silicone stuff you use in the bathroom as a sealant for the edges? That stuff indeed dissolves in alcohol, even when cured. Is stays quite soft and sticky, so can't imagine it to be any good as a coating....

[lightandfrost]

Reference Hermans' comment

I am guessing this would preclude simple spinnaker tape repairs as I doubt that tape would stick to the silicone etc but that maybe a small price to pay.]

A tape patch was tested and the white spirit did not affect the glue on the spinnaker tape patch. Some in our group use spinnaker tape and some use gypsum tape with rubber cement.

Reference evan

We are a Self Organizing Kite Group see the profile. There is no one single person. Those with similar problems have come together to solve a specific issue. In this kite sealing matter, one person tried Acetone but it failed. A second person brought over some white spirit and it worked. Person one had given up on the idea till person two recommended a different solvent be tried.

The use of silicone to seal kites is recommended in many links on the net from youtube to Pansh Facebook groups. It did not originate in this thread or by the authors of this thread. The problem is that several said they used Acetone. Acetone was tried and failed. HOWEVER white spirit did dissolve the silicone as it disappeared completely in solution and was applied to the kite cloth easily leaving a sealed glossy surface.

Why alcohol is mentioned here is unknown and there are many types of alcohols. However it sounds like the alcohol is only softening the cured silicone not putting silicone into solution. However if you suggest an alcohol type a test could be conducted for you easily.

Kite hydrofoil racers might explore smoothing the kite surface with silicone to see if it givens them a slight edge.

[evan]

Sorry, was confusing white spirit with spiritus (cleaning alcohol)

But I am pretty sure a silicone based coating is something different than Dissolved hardware store silicone sealant. Also don't see how the surface of a kite will get smoother by applying an extra layer of coating as you want a flexible as possible cloth to have the least wrinkles.

Flysurfer did reduce the amount of silicone based cloth in the leading edge part of the vmg2 as water beads up on silicone and severely degrades the performance to a point the first vmg became useless in the rain.

[lightandfrost]

L&F have treated six kites with this mixture of Silicone and White Spirit. In every case the kite flew better after treatment and air retension was restored.

One downside has been experienced. Normally rips are repaired using common rubber cement and gypsum tape. However it was found that glue did not adhere to the silicone treated cloth.

To solve this the area to be patched was cleaned with Charcoal Lighter fluid. The fluid was rubbed on with a soft cloth and the silicone came off.

Once the area dried the gypsum tape with rubber cement was then applied to the ripped area and the glue held fine.

[kitexpert]

L&F have treated six kites with this mixture of Silicone and White Spirit. In every case the kite flew better after treatment and air retension was restored.

One downside has been experienced. Normally rips are repaired using common rubber cement and gypsum tape. However it was found that glue did not adhere to the silicone treated cloth.

To solve this the area to be patched was cleaned with Charcoal Lighter fluid. The fluid was rubbed on with a soft cloth and the silicone came off.

Once the area dried the gypsum tape with rubber cement was then applied to the ripped area and the glue held fine.

Or you can just take a piece of spinnaker cloth and wet and glue it with that dissolved silicone. At least I did 15 years ago and I don't remember it failed. Repair made like that can be almost invisible.

You can also use some solvent to PU glue which is stronger than silicone and use that as a wetting/impregnating glue

One thing which could be worth testing is how modern clear construction adhesives would work when thinned with a some solvent. Those should give stronger bond than silicone

[lightandfrost]

To kiteexpert

Could you provide some examples of modern clear construction adhesives that are for sale today?

Do you think PU glue increases the tear strength of the cloth. Silicone seals the cloth well but does not appear to increase the tear resistance by much if at all.