Hi everyone, I was given a FS S3 19m deluxe from a guy in Hawaii to use during my recoating testing. Over the years he tried a bunch of different ways to reseal his kites as they seemed to be particularly affected by the strength of UV in that part of the world but has now given up on the resealing caper, hence I have his 19m S3 which is apparently unable to hold pressure and fly anymore.
A perfect specimen for the full treatment.
Alas there is a problem: the entire kite is covered in a spray can PU coating. This coating is completely degraded and turns to powder when you work the cloth between your fingers.
Any thoughts on the best way to remove the coating? There is not much point using the Goop / Xylene mixture if it doesn't have a solid substrate to grab onto it.
I have machine washed the kite in hot water and soap with no luck (this method worked perfectly for when I removed the old hydrolysis affected PU coating from my MSR tent, removing all traces from the ripstop nylon which I then recoated with Goop/Xylene).
Other methods that have popped up is to use an ammonia cleaner (I did a test with this on a wingtip today without any noticeable result, although maybe the mixture wasn't strong enough).
Next thought was to spend some time dragging the deflated kite across dry sand and my local, but I have my doubts on the effectiveness of this.
I did apply a smear or PVA wood glue to a small patch, let it dry and then peeled it off. This worked quite well as the PVA stuck to the degraded PU and removed it. The problem with this approach as it is extremely slow and uses a large amount of PVA as it needs to be quite thick to be strong enough to peel off in a solid sheet.
Any comments or suggestions would be much appreciated.
I take you mean spray PU varnish? Try search the net how to remove that. You will need to spot test different chemicals. At a guess acetone, things like xylene, toluene are good options. What ever works you'll need a lot and to soak the kite in it. Again test soak a piece of fabric so you know what will happen.
Soak it in a bathtub of extra strong trisodium phospate with laundry detergent and water solution overnight, then another night in bathub full of water based automotive parts degreaser solution. Then wash as you did before. You should be left with a lightweight weave of ripstop nylon. Also try getting a quote from your local non-environmentally friendly drycleaner that uses the old fashioned tetra cholo ethylene solution. Any printing or logos will most likely also be gone. Hope it works!
AeroJere wrote:Soak it in a bathtub of extra strong trisodium phospate with laundry detergent and water solution overnight, then another night in bathub full of water based automotive parts degreaser solution. Then wash as you did before. You should be left with a lightweight weave of ripstop nylon. Also try getting a quote from your local non-environmentally friendly drycleaner that uses the old fashioned tetra cholo ethylene solution. Any printing or logos will most likely also be gone. Hope it works!
So I have found a supplier of trisodium phosphate and am going to go ahead with your suggestion but would like to ask what ratio constitutes extra strong? For example would 1kg be enough for a bathtub or would need more? How much laundry detergent would you also add?
So I bought a second hand 44 gallon (220 Litre) plastic barrel the other day from my local Mediterranean food importing co-op as my partner said there was more chance of hell freezing over than me soaking my kite in our only bath for a week. It should work well, although my kite will likely smell like olives when I'm done...
First solution is 1kg Trisodium Phosphate and a half a box of laundry detergent in about 80 litres of hot water.
After a couple of days in the Trisodium Phosphate mixture I removed solution and filled the barrel with clean water a couple of times to rinse. I then removed the kite and emptied out the rinse water and replaced with a solution of 40 litres of hot water and 5 litres of water-based degreaser concentrate. I then replaced the kite and left it there (agitating every 6 hours or so) for a couple of days more. Once again, after removing this mixture I filled the barrel with clean water and rinsed the kite. I then immediately put it through two 40 degree temperature cycles on my washing machine and hung out to dry.
Well, firstly my kite is pink (but at least it doesn't smell like olives). A little digging has led me to the conclusion that far better than degreaser would have been caustic soda granules mixed to about the same ratio, as that is what is the main active ingredient in degreaser anyway (with the added bonus of no added pink dye and more cost effective to boot). My only concern with using caustic soda would be getting the mixture too strong and dissolving the stitching (apparently Nylon is quite resistant to Caustic Soda but Polyester no so much).
Secondly, it worked, but just ok. I am still partway through the extremely tedious job of going over every square centimetre of the upper surface (I have thankfully completed the lower surface) rolling the fabric between my fingers to turn patches of the still intact coating to dust. I then plan to put the kite through one more hot wash before I decide to either proceed or give up.
I'll keep you all posted.
Ps, if ever anyone reading these forums is even considering using a can of spray-on PU or other such product to 'fix' your ageing kite's porosity, for the love of God, don't.
Axel has certainly taken this to another level. Some of us should try everything at least so the others don't have too Recoating is certainly worth while, cleaning like this does not sound like it. I wonder if a Drycleaner could do anything? Their machines are designed to wash large things or amounts, and with unusual chemicals. I was recently reading about liquid CO2 being an excellent solvent
windrider1 wrote:Is all of this really worth it? Im pretty sure u destroyed the fabric of this kite with all those chemical baths.
Ha, ha, depends who you ask I guess. To be honest, I would not go down the path of removing a coating again, as per Foilholio's comment way too much trouble. I didn't know however that a friend of the previous owner had tried to recoat it before I agreed to take it. As for the chemical baths, the fabric itself seems completely fine at this point.
The problem is I'm a sucker for seeing out a project until it's completed (and for free stuff). I also do not have a light wind kite (or upwards of $2K to purchase a S4 Lotus).