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Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 11:23 am
by nothing2seehere
So 4 of my valves on my kite have decomposed and now leak in the hard plastic. Ordered some new replacement valves - but I am at a loss to get the old valve base unglued from the bladder. Its great that I won't need to worry about glue un-sticking but the plastic the valves are made from seems too fragile for such a permanent fixing.

The valve base has a rippled texture so I can't just glue on the top. Likewise, I really need the material that it is glued to so I can get a long lasting finish.

I have tried boiling water and its not making a dent. Any ideas?

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 11:47 am
by Herman
I dare say this is not the case but I have been surprised to find a very rippled textured valve glued on the inside rather than outside of the bladder. I was able to unglue it in the usual way and pull through small hole but it was fiddley.

If all else fails you could cut them out and use base doughnuts, oversized based valves or a good old patch. If needed mark an oversized cross on the bladder to have a datum for valve position.

I use hot water rather than hot air as it easier to control max temps reached. Good luck!

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 12:16 pm
by nothing2seehere
Thanks.

Glued on the top of the bladder so no problems with extracting. Unfortunately I ordered the regular sized replacements.

Any experience with Acetone/nail polish remover? I'm assuming its a PU glue that was originally used and that seems to be the first port of call.

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 12:39 pm
by Herman
The solvent/thinner for polyurethane glue is usually toluene based. COTOL is a commercial thinner for polyurethane glue if memory serves.

Sorry I don't have any experience with dissolving set polyurethane or how various solvents react with bladder material.

If you have to cut you can still use what I am calling a doughnut to turn your standard valve into a wide based valve. They are like a giant penny washer of tear aid.

I understand your reluctance to cut but it may be more time efficient in the long run. Again good luck, please let me know what you learn if you experiment with solvent.

Regards Herman

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 12:45 pm
by Herman
Further thought, the PU glue was probably thinned with toluene at application and so this infers toluene is safe with bladder material but I do not have any proof of this hypothesis!

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 1:01 pm
by FLandOBX
I always use a hair dryer or small electric heater. Hold the valve close to the heat for a minute or two and then slowly begin peeling up the old valve.

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 1:21 pm
by nothing2seehere
Thanks. Its had a good 15 minutes in boiling water and no peeling at all so its going to have to be a cut and doughnut job. :o

I think how well the first valve goes will let me know whether I bodge the rest of them (this one was originally air tight with a bandage of aqua-seal and electrical tape) until they get worse.

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 1:22 pm
by JaZone
nothing2seehere wrote:
Thu Jun 20, 2019 11:23 am
So 4 of my valves on my kite have decomposed and now leak in the hard plastic. Ordered some new replacement valves - but I am at a loss to get the old valve base unglued from the bladder. Its great that I won't need to worry about glue un-sticking but the plastic the valves are made from seems too fragile for such a permanent fixing.

The valve base has a rippled texture so I can't just glue on the top. Likewise, I really need the material that it is glued to so I can get a long lasting finish.

I have tried boiling water and its not making a dent. Any ideas?
Can you post a photo ?
Which brand kite is it?

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 2:15 pm
by edt
If it's a triple seal with a wrinkly texture then part if it is heat sealed and you won't be able to get it off. glue should come off rather easily if you put hot water on it. You should be able to cut away part of the top section to get to the polyurethane which is where you can do the restick. Sometimes there's no other option than to cut the whole thing out, place a big tear aid type a repair and then restick on your patch. I know why they make it this way it's so that it's more sturdy but these double and triple layers are the worst to repair, a lot of times you just have to cut it out.

Re: Help with removing glued valves from bladder

Posted: Thu Jun 20, 2019 3:31 pm
by grigorib
nothing2seehere wrote:
Thu Jun 20, 2019 11:23 am
So 4 of my valves on my kite have decomposed and now leak in the hard plastic. Ordered some new replacement valves - but I am at a loss to get the old valve base unglued from the bladder. Its great that I won't need to worry about glue un-sticking but the plastic the valves are made from seems too fragile for such a permanent fixing.

The valve base has a rippled texture so I can't just glue on the top. Likewise, I really need the material that it is glued to so I can get a long lasting finish.

I have tried boiling water and its not making a dent. Any ideas?
Use hairdryer to heat them up and they'll peel like a ripe clementine.