Need help with Bladder micro-puncture

[dracop]

Hey guys I need your help. I have a problem with the bladder on my 2013 NRG, it started losing air pressure after my least session. Doing an ear test, I was able to find the air leak, its close to the very tip of the wingtip (see pictures).

Interestingly, after pulling out the tip of the leading edge bladder and packing it back in, the leak stopped leaking without any additional work - seems to have self healed somehow. It now holds firm air pressure for 1+ hour without loss and the audible air leak is gone. Still, it has a nipple that clearly means its a problem.

My Liquid Force kite came with a self repair kit that includes a small bladder patch and some type of adhesive. The small patch has a light sandpaper backing with a 3 sentence intrusction print that says lightly rough up the bladder, apply patch, and bam you're done.

I was considering applying that in lieu of ironing the bladder.

Should I use the patch, iron it, do nothing and see if problem re-emerges? Right now I am leaning towards the stick on patch since the bladder is holding on its own - I've taken it back out, re-inflated, put it back in, re-inflated like that (so I can see how it does under pressure inside of the LE), etc and the leak just isn't there anymore altho you can visually see the nipple.

On a side note, pumping, deflating, and re-pumping a 16m kite is exhausting work - I really need an electric pump lol.

[edt]

you want to patch it.


The reason that you have to seal the ends of bladders for holes near the end is that most of the time the bladder bursts along a seam, you know where the two parts of the bladder comes together and there's a little ridge.

If you try to apply a patch along a seal it almost always will come off because air works along the seam and gets out.


Your particular hole is not along a seam. Patch it!

Be extra careful not to make any creases you have that bubble there. If you get a wrinkle in the patch it will fail.

[dracop]

thanks!

[dracop]

One Step Forward, Two Steps Back

So I patched the bladder, pumped it up hard to see if it would hold. The end seam of the bladder on the wing blew out right at the seam. The patch held! But the main seam did not. So now I have to fix that. Not sure if I secured the edge properly with the velcro flap/fold, its done now.

Is it as simple as putting the bladder on a flat surface, covering it with a sheet of parchment paper, and ironing it so that the heat melts the plastic together? After watching some videos on Youtube for bladder repair, that was my takeaway but nervous about it. Suppose I should not be nervous since if I screw up on the self repair I end up in the same spot as buying a new bladder.

On a related note, the seam seems kind of fuzzy. Anything crazy here? See the pic of the white seam.

[William Munney]

It looks like you've got some creases in the patch that will probably cause a slow leak. The tiniest crease can leak.
With an iron you have to use some thin cardboard and experiment with the amount of time and heat. Putting it back in the kite, the end of the bladder should be in that little sock that sticks out, fold the sock up with the bladder still inside and tuck it back in.

Check the bladder with soapy water before you put it back in.

[edt]

it is incredibly difficult to do it yourself with a seam and an iron it took me about 100 tries before I got my first good seam. Get someone who has an impulse sealer that works good. Or just replace the bladder, you can't have wrinkles in your patch it will definitely leak so you will have to cut that out and redo it with an even bigger patch. One Step Forward, Two Steps Back at least your learning something. Your seam has some random fabric stuck in it, I don't think it matters for strength of the weld but it is sloppy work by lf for that particular bladder.

[William Munney]

it is incredibly difficult to do it yourself with a seam and an iron it took me about 100 tries before I got my first good seam. Get someone who has an impulse sealer that works good. .

+1 on the difficulty of getting a good seal with an iron. Has anybody bought one of those $30 12" sealers on ebay or Amazon?

On the crease- saw this old post by Geopeck:

here's a tip for tear-aid - it is really different stuff when warm vs cold. If it is room temp it is super sticky and will probably not come off any place it touches on the bladder. So when you are ready to make your repair and have everything laid out put your tearaid in the freezer for a minute, then apply it. You will have the option to pull it back off if something goes wrong, if you do it quick. Also, if something goes wrong and you can't get it off and you are still leaking through a crease in the bladder or tear aid, put a rag over it and then iron it, looking to get it to 40c or 130ishf. The glue will run out of the tear-aid into your crease and stick. Forever and ever.

[dracop]

Hmm I was considering buying this Impulse Sealer for the job:

http://www.amazon.com/Impulse-Sealer-Ce ... B000UVMKO8

This is the repair approach I am considering, glad you guys warned me getting a seam is difficult with an iron as they make it sound easy.

http://www.kitesurfingschool.org/bladderrepair.htm

It seems they have the same brand impulse sealer as the amazon link altho there are alot of different models from that company that look the same.

One question, why do I have to cut out the bad repair patches vs patching with a larger patch right over it? It has a smooth surface for the larger patch's adhesive to stick to and its got to be better than the larger patch having a section exposed to air.

Suggestions for where I buy a larger patch? Tear aid? Bicycle inner tube patch (others claim its the same material and is definitely more widely available).

Simply buying a new bladder is an idea, but it costs $140 at Airtime. That doesn't even come installed, creating more potential issues if I attempt it myself or more expense if I drive up to Ft Lauderdale and ask them to do it for me (they charge by the hour). This is my fail safe, if I am going to throw away the bladder, doesn't matter if I hack it up trying to fix it anyways.

Miami has no wind on the horizon so I until I fly down to Cabarete in July, the downtime is not an issue.

[edt]

One question, why do I have to cut out the bad repair patches vs patching with a larger patch right over it? It has a smooth surface for the larger patch's adhesive to stick to and its got to be better than the larger patch having a section exposed to air.

Suggestions for where I buy a larger patch? Tear aid? Bicycle inner tube patch (others claim its the same material and is definitely more widely available).

it depends on how you applied the poor patch. It looks like you not only wrinkled the bladder material you stretched it a bit so if you patch over a patch the wrinkle that is now under your current patch will just grow because the bladder material can no longer lay flat. Then you will have to cut out your second patch and make an enormous patch.

You can buy a 5 foot roll of tear aid type a for about $25. remember type a, not type b (type b is only for vinyl).

And yes I have gone through more than one roll of tear aid in a single year. Something about putting a patch on a patch on a patch lol.

Inner tube patch is slightly different it is designed to take 100psi so it is thicker and won't stretch as easily as tear aid type a. So yes it is the same stuff but I would still use tear aid type a because it will stretch with the bladder better.

When using a jumbo patch don't forget to put a paper towel inside the kite so you don't accidentally tape your bladder to itself.

Do not weld a seam of your actual kite on your first try. You will have to practice on an old bladder if you don't have any old bladder ask around, someone will gift you several feet of old bladder to practice on.

I was the same way when I first started fixing the bladders on my kites oh my goodness the messes I made of my bladders. I eventually figured it out, but even I sometimes give it up and just buy a new bladder.

[dracop]

Do not weld a seam of your actual kite on your first try. You will have to practice on an old bladder if you don't have any old bladder ask around, someone will gift you several feet of old bladder to practice on.

I was the same way when I first started fixing the bladders on my kites oh my goodness the messes I made of my bladders. I eventually figured it out, but even I sometimes give it up and just buy a new bladder.

When you say do not weld a seam, are you including the impulse sealer? Thats what I was going to use for the seam and after seeing Tear Aid Type A rolls on Amazon, I was going to grab that for the patch.

I do not have any old bladders laying around, would be great to experiment on first to get the process down better before touching my kite.