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heat sealing valves to bladder

Posted: Thu Oct 05, 2017 3:20 am
by toddsphresh
is their anyway you can heat seal valves to a kite bladder at home? any tool you can buy. i would love a way other than aquaseal or glue to attach kite valves to the bladder. thanks for any advice.

Re: heat sealing valves to bladder

Posted: Thu Oct 05, 2017 3:30 am
by edt
No. Valves are made of some sort of hard plastic with softener added to them, while the bladders are made of urethane. You can only heat bond urethane to urethane, which by the way was tried by various companies around 2005 or so. I owned a kite with a heat sealed bladder, the problem is that while the valves would never fail they got brittle and cracked. Glue (or if you are in a hurry a patch or restick valve) remains the best way to restick valves. The reason the valves fail by the way is that the softener chemicals in the valves migrate out to the edges of the plastic and that causes the glue bond to fail. If you take an older valve and restick it, no matter how long it lasts it won't fail again. Make sure you properly clean the valve before a restick and it should last another 10 years. Resticking with glue is a great way to fix a valve. It is a permanent and good fix. You gain nothing by wanting to do a heat seal.

Re: heat sealing valves to bladder

Posted: Thu Oct 05, 2017 3:35 am
by toddsphresh
not true my stupid valves will crack at some point no matter what. any valves where the glue is good crack and then the ones where the valve is good the glue will fail. i just hate that replacement valves are so expensive

Re: heat sealing valves to bladder

Posted: Thu Oct 05, 2017 10:16 pm
by GregK
Todd - as edt posted, almost all kite bladder valves are made from PVC, and the kite bladders thermoplastic urethane. In the kite factories, the valves are thermally welded to the bladder film using RF ( radio frequency - akin to a microwave ) welders, thus very difficult to do without expensive equipment and tooling. Plus welding the two dissimilar plastics with a strong and durable bond is extremely challenging, and with time, accelerated by heat and moisture, the softeners / plasticizers in the PVC migrate to the weld bond area and weaken it.

If the area on the bladder where the valve is intended to be is flat and free of deformation, bulging or thinning, then a KiteAid valve donut ( https://www.kiteaid.com/collections/all ... -donut-kit ) will work, and are removable ( by soaking in a solvent that will soften the adhesive but not damage the bladder film ) should the valve crack later. And they are fairly inexpensive.

Re: heat sealing valves to bladder

Posted: Thu Oct 05, 2017 10:27 pm
by GregK
Todd - start up a business selling replacement stick-on valves and you will very quickly understand why they cost what they do.

Re: heat sealing valves to bladder

Posted: Thu Oct 05, 2017 10:57 pm
by rogue_kiteboarder
GregK wrote:
Thu Oct 05, 2017 10:27 pm
Todd - start up a business selling replacement stick-on valves and you will very quickly understand why they cost what they do.
The average cost of a Fix My Kite self stick valve is like $13. When compared to the cost of the kite, they are very inexpensive.

Re: heat sealing valves to bladder

Posted: Fri Oct 06, 2017 5:38 am
by windmaker
rogue_kiteboarder wrote:
Thu Oct 05, 2017 10:57 pm
GregK wrote:
Thu Oct 05, 2017 10:27 pm
Todd - start up a business selling replacement stick-on valves and you will very quickly understand why they cost what they do.
The average cost of a Fix My Kite self stick valve is like $13. When compared to the cost of the kite, they are very inexpensive.
They are expensive compared to the price of buying a new leading edge bladder though, especially if you have to replace all 7 which is usually the case, not worth it.

Re: heat sealing valves to bladder

Posted: Fri Oct 06, 2017 2:22 pm
by rogue_kiteboarder
windmaker wrote:
Fri Oct 06, 2017 5:38 am
rogue_kiteboarder wrote:
Thu Oct 05, 2017 10:57 pm
GregK wrote:
Thu Oct 05, 2017 10:27 pm
Todd - start up a business selling replacement stick-on valves and you will very quickly understand why they cost what they do.
The average cost of a Fix My Kite self stick valve is like $13. When compared to the cost of the kite, they are very inexpensive.
They are expensive compared to the price of buying a new leading edge bladder though, especially if you have to replace all 7 which is usually the case, not worth it.
So, replacing all the valves on a kite for $91 is very expensive? I don't think it is. And buying a new LE is not an option for a whole lot of people because of the age of their kite, the wait time to get it and the delay in getting on the water. Most shops do not stock OEM bladders because of the ridiculous number of different brands, models and sizes of kites. So, special order it is, if you want to wait. And the cost of a new OEM bladder is generally higher than the cost of just replacing the valves. Ozone leading edge bladders cost about $140 on average, and that is for a 3 strut kite with a boston valve.

Re: heat sealing valves to bladder

Posted: Fri Oct 06, 2017 4:07 pm
by edt
$12 for a small bottle of 3m 5200 red or aquaseal will do at least 100 valves. But it's nice to have both the glue and the stick on valves. When you are out kiting and a valve gets a leak it's nice to be able to fix it at the beach. It's not too bad buying a custom bladder either but I almost always only buy bladders and struts for those damn pinhole leaks that are impossible to find.

Re: heat sealing valves to bladder

Posted: Sun Oct 08, 2017 4:55 pm
by toddsphresh
Replacement LE 70$ for a 7m replacement valves 5x14 +3 x at least 15=too much. Sorry theirs no way cost on those things is more than 1$ a piece no way.