Contact   Imprint   Advertising   Guidelines

Recoating kite fabric

For all foil kite riders


foilholio
Very Frequent Poster
Posts: 1843
Joined: Sun Aug 23, 2015 3:20 am
Kiting since: 1337
Local Beach: Ventura Beach
Favorite Beaches: Tarifa
Style: Airstyle
Gear: Foils
Brand Affiliation: None

Recoating kite fabric

Postby foilholio » Wed May 04, 2016 4:53 pm

A long time ago I recoated a kite using silicone rubber diluted in turpentine. The intention was to improve the rather dismal waterproof state of the kite. The silicone rubber achieved that quite well and in addition made the kite hydrophobic!, dirt repellent and much more air tight. From memory I think it added about 200 grams to a 17m kite. Silicone is not a particularly strong material. I postulated that Shoe Goo, which is actually Styrene Butadiene Rubber, a much stronger and flexible rubber than silicone would be a better coating. Someone on foilzone picked up on a bit of this and actually threw silicone rubber and Shoe Goo, with some other coatings as well like PU foam into a grand test. His testing methodology was quite thorough, involving weathering and durability tests and also scientific with a home made porosity meter. What surprised me was silicone rubber got eliminated quite early, as I had already found it quite good. Then also PU foam got eliminated as it developed cracks that leaked, somewhat surprising as it was touted as being very good on various french forums, but even in my own tests I could see a cracking problem and of course the PU coatings on flysurfers are horrible, with peeling and flaking. He narrowed it down to 2 candidates at the end, Shoe Goo and an unnamed product. Yet to reach his final conclusions he was already quite impressed with both, but then foilzone fell into a black hole.

I already knew about Shoe Goo, but he enlightened me how to thin it, easy enough if you read it's sds I guess, the solvent is toluene. Reading on the net you will quickly discover many people are thinning Shoe Goo or it's derivatives for the purposes of gluing or waterproofing. It is actually sold under many different names with merely different concentrations for the uses of sealing seams to gluing shoes and everything in between. Recently I discover E6000 a thinner 30% solids formula of Shoe Goo, and it is great for gluing patches on kites and fixing wetsuits and many other things. I started a thread about it viewtopic.php?f=1&t=2392220&p=925144. Though I think I will make my own lighter dilution from shoe goo for glueing patches now.

Anyway I have a 8m kite, very used and quite old ,porosity of the fabric can only explain its bad behavior. So I decide to coat it with Shoe Goo. I clean, rinse, fly, dry the kite to get as much sand as possible out of it. I inflate the kite with a fan on a plastic tarpaulin and hide the bar and what ever bridles I can under the kite. One tube of shoe goo is 109.4ml with a specific gravity of 0.898 so 98grams. I squeeze about 45 grams out into 100ml of toluene and its already about half the tube so I stop. I mix it well then add a further 350mls toluene for a 1 to 10 ratio. I coat with a spray gun one side of the kite recoating a few times on the tips which I know the coating is peeling everywhere inside and any trouble spots like repairs etc. Preparing the next mix for the other side I was only just able to squeeze 46grams out of the tube :-/ The toluene evaporates within a minute so I just let the kite dry while I mixed the next lot and while I packed up.

The kite has quite a shiny metallic appearance with it much more so on the tips where I applied more coats. The fabric has a plastic feel to it and is quite crunchy like new kite fabric or even more so. Which I didn't expect because the silicon coating is not like that. It may be something to do with the PU inside bonding to the shoe goo. I haven't fully tested the waterproofing as that is not my main focus, but if it is thick enough It will prevent the fabric absorbing water obviously. Flying the kite I already notice it intakes air much easier setting up and the general behavior seems much improved. Oh and it smells like a new pair of shoes lol :-)

I did some tests before and after. Pegging the tips shut I inflated the kite and let it deflate taking some very rough estimates at different times about it's inflation level

before I got
12min 50% deflated , 30min 80% deflated , 40min 90% deflated

after I got
10mins 20% deflated , 25mins 50% deflated , 50mins 70% deflated

I also weighed the kite with bar and bag before 3.67kg and after 3.66kg. Which I guess the kite dried and lost more sand in the weeks between measurements and when preparing just before spraying, oh well. Shoe goo is 46% solid by weight
tds-shoegoo-english.pdf
(401.54 KiB) Downloaded 97 times
so 91grams wet becomes 41.8g and I wasted anywhere from 10to50% ,air spraying has a lot of bounce and the droplets don't stick, so the added weight could be anywhere from 21g to 38g. Not much considering the results. I wish I had weighed it just before spraying though to know exactly. I think when and if I do it again I will double the application rate to 2 tubes per 8m of kite and drop the dilution to probably 8 or 7 to 1. I will probably get an airless sprayer to use as well. But so far I am quite impressed and I can always coat again, but removing would be tricky :-)

foilholio
Very Frequent Poster
Posts: 1843
Joined: Sun Aug 23, 2015 3:20 am
Kiting since: 1337
Local Beach: Ventura Beach
Favorite Beaches: Tarifa
Style: Airstyle
Gear: Foils
Brand Affiliation: None

Re: Recoating kite fabric

Postby foilholio » Sun Aug 28, 2016 11:45 am

I finally got to use this kite again. The behavior of it is much improved. Obviously porosity has quite the effect on foils. Waterproofing seems quite good, water beads and doesn't seem to soak in. It is like the lotus in that way but not quite as good. Maybe if I had applied more it would be more like the lotus, but already it is close and very good. The appearance and feel is just awesome, the kite is crispy like new or better. It feels plastic and more solid, in the air it has this grey metallic shine to it 8) . I look forward to trying it on another kite in the future.

I think for brands making foils this would be worth investigating. I think applying the coating after sewing offers great benefits to seal sewing holes and seams, like on the TE where sand gets in.

User avatar
Kamikuza
Very Frequent Poster
Posts: 5401
Joined: Fri Jan 09, 2009 4:49 am
Local Beach: Sabae Beach
Favorite Beaches: Ol' Stinky
Gear: This, that, the other

Re: Recoating kite fabric

Postby Kamikuza » Sun Aug 28, 2016 12:19 pm

Always wondered what the unnamed product was...

So you just sprayed it onto bridles and all?

Is there a brand name for toulene? Took me ages to find IPA here because "rubbing alcohol" isn't used :roll:

The NikWax stuff though is easier to find. I can't remember if it was "good enough", compared to the effort of shoe goo etc...

foilholio
Very Frequent Poster
Posts: 1843
Joined: Sun Aug 23, 2015 3:20 am
Kiting since: 1337
Local Beach: Ventura Beach
Favorite Beaches: Tarifa
Style: Airstyle
Gear: Foils
Brand Affiliation: None

Re: Recoating kite fabric

Postby foilholio » Sun Aug 28, 2016 1:03 pm

Me too I still wonder. A secret that will perhaps remain secret :-0

Yes I spray it onto the lot. Hid what I could under the kite. For the top there is no bridles. Really not much would get on them anyway.

I am sure there is brands for it I just got it out of a large drum from a car paint supplier, apparently they use it and it was cheap. A lot of hardware stores have it too and paint shops. Another name for it is toluol.

Nikwax doesn't last long and won't give anywhere near the results this does. This is like new kite results. If you could make this work( I am sure it would) with an airless spray gun it would be quite quick and easy.

User avatar
Kykeon
Medium Poster
Posts: 65
Joined: Mon Jul 27, 2015 4:25 pm
Kiting since: 2014
Style: Freeride
Gear: .
Switchblade 10m 2016
A15 12m

Spectrum 136cm 2016
Shinn El stubbo
Zeeko Blue & White
Brand Affiliation: $iemens

Re: Recoating kite fabric

Postby Kykeon » Sun Aug 28, 2016 3:29 pm

very interesting, thanks for sharing foilholio.

I guess you already knew some commercial products for that purpose (ultramar?).
Had you considered using them?

I assumed that from the 4 "surfaces" of the foil, you applied only on the 2 outers, right?


Kamikuza, if you read the specs of this product, you can find many solvents. Some of them should be very easy to get anywhere. (but not sure if they would be bad for the fabric...)

foilholio
Very Frequent Poster
Posts: 1843
Joined: Sun Aug 23, 2015 3:20 am
Kiting since: 1337
Local Beach: Ventura Beach
Favorite Beaches: Tarifa
Style: Airstyle
Gear: Foils
Brand Affiliation: None

Re: Recoating kite fabric

Postby foilholio » Sun Aug 28, 2016 7:49 pm

I had heard of Ultramar(kite refit) but never really looked into it much. Looking at the cost it's about 20x more expensive than what I did. It is also hard to find out what exactly it is, from a little reading it sounds like it is PU which generally aren't great. A safety data sheet would be nice but I can't find one. Thread on Ultramar http://www.powerkiteforum.com/viewthread.php?tid=23444. A well expressed Pansh hater there ,"bigkid", seems to be in love with it. I wonder how well it air tights the fabric vs water proofs it. Not all products are great at sealing against air and that was my goal. http://forum.kitecrowd.com/kitesurfing/ ... 10172.html
peter32 wrote:I Ultramared my very well used 15m speed 3 , it worked like magic water off a ducks back Style ........few months later exactly the same as it was before i used it . wont bother again didn't last me long.
Sounds like it is similar to nikwax and a waste of time and money :-(.



The shoegoo coating I did is applied from the outside. It soaks into the fabric penetrating it and sealing between the fibers. So in essence it is coating on all sides ( 4 surfaces).

There is only 2 solvents that are relatively safe ( you still need to be very careful) I know of that work well with shoegoo they are toluene and xylene. Another more dangerous one which is in e6000 is Tetrachloroethylene it is much much more lethal and I don't recommend using it having read about it.


I think I found some posts from the same guy who was testing on foilzone, before he did any testing though. http://www.paraglidingforum.com/viewtop ... c&start=50 user "tristanj"

User avatar
Kykeon
Medium Poster
Posts: 65
Joined: Mon Jul 27, 2015 4:25 pm
Kiting since: 2014
Style: Freeride
Gear: .
Switchblade 10m 2016
A15 12m

Spectrum 136cm 2016
Shinn El stubbo
Zeeko Blue & White
Brand Affiliation: $iemens

Re: Recoating kite fabric

Postby Kykeon » Sun Aug 28, 2016 10:01 pm

thanks for the clarifications.
The pdf you have attached mentions gasoline as solvent as well. Would it be an option?

foilholio
Very Frequent Poster
Posts: 1843
Joined: Sun Aug 23, 2015 3:20 am
Kiting since: 1337
Local Beach: Ventura Beach
Favorite Beaches: Tarifa
Style: Airstyle
Gear: Foils
Brand Affiliation: None

Re: Recoating kite fabric

Postby foilholio » Sun Aug 28, 2016 11:33 pm

I don't know. Maybe they mean for cleanup? I think acetone dissolves it too but it won't cure right with acetone. There is probably a number of things that will dissolve it but may ruin it from curing correctly. Things like gasoline may also damage the fabric. You would have to test or read what it does to polyester or nylon. There is also a bigger fire risk with gasoline than toluene. I am only using toluene because of what I read on the net and it is the solvent used in the glue currently. I do see what solvents it says in the pdf

Chevron solvent 1100
Chlorothane NU
Cyclohexane
Gasoline
Methylene chloride
Perchloroethylene
Propyl acetate
Toluene
1, 1, 1-Trichloroethane

They could be listed as warnings not to use where it comes in contact or for cleanup, who knows? Toluene works and so does Perchloroethylene(Tetrachloroethylene) as they are already used, but xyxlene isn't even mentioned and that is used by many on the net.

I will test some gasoline when I get a chance though.

EricSanders
Rare Poster
Posts: 47
Joined: Mon Aug 24, 2015 2:39 pm
Kiting since: 2015
Local Beach: Metro Beach Detroit
Favorite Beaches: Tawas, OBX
Style: Freeride
Gear: Blade Trigger 7.0
LF NRG 10.0
Best Kahuna 13.5
Blade Fat Lady 17.0
Royal Rush 19.0
Pansh Aurora2 22m
Spleen door 164
OceanRodeo Mako King
Liquid Force Edge 146
Axis Vanguard 148
Axis Vanguard 136
Brand Affiliation: None
Location: Brighton, Michigan

Re: Recoating kite fabric

Postby EricSanders » Mon Aug 29, 2016 2:49 am

Interesting, thanks for the post.

User avatar
Kamikuza
Very Frequent Poster
Posts: 5401
Joined: Fri Jan 09, 2009 4:49 am
Local Beach: Sabae Beach
Favorite Beaches: Ol' Stinky
Gear: This, that, the other

Re: Recoating kite fabric

Postby Kamikuza » Mon Aug 29, 2016 7:56 am

Why airless sprayer?


Return to “Foil Kites”

Who is online

Users browsing this forum: pmaggie and 3 guests