Sorry mate saw this yesterday other morning but got distracted by other things.
Any bladder is very easy to fix these days, thanks to a new product called Tear Aid
www.kitepower.com.au/collections/kitesurfing/SPGeneralThe kit pictured in that link has 1 piece 6" long, which may not be long enough for you hole, but we also have it in 5 foot long x 3 inches wide rolls, which will fix any hole (almost).
The stuff is flexible and is a permanent fix, in fact a bladder repaired with this stuff will never burst in the same place as the repair.
A simple tip is to get the bladder out of the kite and wash it out, by turning it in side out through the hole that needs repair, dry it thoroughly. Then tape the bladder to a laminex tabel top with packaging or masking tape to get the section needing repair as flat as possible, then apply the Tear Aid, press the Tear Aid down firmly and then test inflate the bladder. Check along the edges of the patch, if you have leak still, cut a 2cm wide strip and cover that section overlapping onto the first patch a bit, then re test, should be good to go.
Use lots of talc to re insert the bladder and inflate to 60% and check for twists, before inflating fully, any twists, remove and refit.
Use a flat piece of carbdboard attached to a string to pull the bladder in so that the bladder cannot twist, alterntively, use a bit of yellow tongue plastic flooring sheet joiner.
This Tear Aid stuff is the miracle cure for older kites that are impossible to get new bladders for. Repairs anything inflatable, including boats and mattresses, etc too.
Cya and
Goodwinds
Steve