If the kite bladder gets busted
Kitesurfing is a sport for adventurers! When the wind hits the kite and I glide over the blue water weightlessly, I feel nothing but absolute freedom! The kitesurfers among you have probably just smiled to themselves while reading this, as they know exactly what I mean. But enough sentimentalism, let’s cut to the (technical) chase:
My good friend Oliver, who is a passionate kitesurfer just like me, has recently been to the Ijsselmeer in the Netherlands. While he happily floated across the water, some of the valve sealings on the fronttube bladder came loose. Bladders are thin rubber tubes, which are inflated in order to give the kite stability. Due to high stresses, the tubes are damaged fairly often. But why buy new ones when the old ones can be repaired just as well?
DIY repair – bonding a bladder instead of buying a new one
Oliver and I decided to reattach the valves with adhesive bonding. The only problem: The bladder is made of TPU foil (i.e. of thermoplastic elastomers based on urethane). The only thing you need to know about this tongue twister is the fact that TPU is hard to bond due to its low surface energy.
Yet of course, thanks to WEICON, I knew a solution to this problem: The right adhesive for repairing kites is the WEICON Easy-Mix RK-7300 Structural Acrylic Adhesive, an adhesive for structural bondings based on methyl methacrylate (MMA). Here, the only thing to remember is that this adhesive is specially made for plastics with low surface energy. Another advantage: After just eight hours, the adhesive is cured enough for the kite to be used again.
Where else can TPU be found?
Step 1: cleaning
In order to make the kite airworthy, Oliver and I removed the damaged tube and marked the damaged areas. We carried out the repair works in our holiday home nearby, as sand and dirt are not exactly helpful when working with adhesives.
Which brings us to our next important topic: cleaning. Before the actual reapir, we dried the bonding surfaces thoroughly and cleaned them with WEICON Surface Cleaner. This is the only way to ensure that the adhesive sticks well to the bonded material. You can read all about the importance of cleaning before adhesive bonding in this blog post, by the way.
Step 2: bonding
After cleaning, the Easy-Mix RK-7300 was used. First, I put the included mixing nozzle on the cartridge. The RK-7300 is a two-component adhesive, which only turns into a workable compound by means of the helix structure inside of the mixing nozzle. As soon as the adhesive had been applied to the tube material, I fixated the valve by applying gentle pressure. I covered it with a small glas, so it wouldn’t accidentally move. Then, Oliver and I allowed the adhesive to cure over night.
The next morning, Oliver could already jump on his board again and enjoy letting the kite move him across the water.
More infos on surfing
I don’t want to indulge in clichés, but a surfing tour in a converted van certainly has its charme. And you’re a head-turner in every surf spot, for sure. Read more about restoring an old Volkswagen camper van in this article.
