The Joy of WindFoiling is 100% correlated to the chance of catapulting and striking the nose of your beloved board with the mast while your hooked in, often unexpected when only moments ago you were having a great time feeling totally in control!
This video was the last in a series of crashes that have afflicted my awesome FMX 187 Hyperion. These boards are amazing, which is why I wasn't ready to part with it. But after spending nearly $1000 repairing it last time, I decided this time I would try myself.
I looked into Vacuum bagging, but decided to avoid the extra expense and complexity, instead planning to overfill the cavity with micro-bead filled epoxy filler, and squeezing it tightly to press any excess out.
Step 1 - Cleaning Up Causing Collateral DamageAfter drying the board out (hopefully obvious) the first step is to clean up the damaged area... which may involve causing more damage. I did use a saw to cut a few straight lines, and some power tools to clean inside the front nose area. Try not to over-sand and cut through the carbon, which of course I did do a few times.
Step 2 - Delamination CatastrophicationDuring the clean up and inspection it became obvious that one section of the underside skin had delaminates about 25x50cm. This was a bit of a problem, but actually easier to fix while the skin is open. I ordered a large 100mm syringe and tube online which came in very handy for squeezing epoxy into the small gap while the board was raised on one side... allowing the resin to fall deeper into the grooves. I rolled the board around all axis' a few times before weighting the skin down with a bag of fertiliser (25kg) and a water bottle (5kg) to ensure good contact between the skin and foam. 24hours later the board seemed to be relaminated successfully without the need for a vacuum.
Step 3 - Filling In The GrooveNext I had a rather large gap to fill. Previously I had made the mistake of using expanding foam to fill a cavity. DO NOT USE EXPANDING BUILDERS FOAM! It is hydroscopic and soaks up water. While I am at it... do not use silicon to seal a gap temporarily either as it will make subsequent repairs harder.
Instead I used a foam esky, cut to size. Small pieces where needed, carefully shaped with a sharpe knife. Sawing back and forth will cut and give a smooth surface, while pressing hard to cut will often tear the foam beads apart leaving a rough surface!.
Reinforcing was applied with some DivinyCell hard foam about 10mm thick. Some extra DivinyCell was used as vertical reinforcement.
Step 4 - Glassing DownWith all the inserts cut to size I next needed to cut the reinforcing fibre-glass to slot between layers of foam to help the epoxy bond. I had to trim a few of the foam pieces again as the fibreglass added a mm of thickness and I didn't want the foam to dome and create an air pocket!
Step 5 - Getting WetFinally the big day came... time to get wet. With all the pieces laid out, I mixed up some filler with about 2 parts glass bead powder to 1 part epoxy resin. Although I didn't, it is probably best to mix the resin first and adding the glass to the mix. I had some slow harder left over for a small batch which I tend to prefer. The new bottle of fast hardener can overheat much more easily if over concentrated, which can melt foam!
With all the obvious gaps filled, I inserted the foam pieces, a bridging piece of glass wetted with pure epoxy resin, more foam, more filler, more glass mat and more pure resin.
With everything wet, I wrapped the repair in a layer of 'Peel-Ply' which is designed to absorb excess resin and let it break off easily.
Step 6 - Clamp ItQuickly so nothing had time to set yet I covered the peel-ply with some cling wrap then a board to the underside so I could clamp it down with some large G-Clamps and load spreading timber. Flipping the board over I squashed the deck down with another trusty 25kg of potting mix. I also used some flexible water filled ice-bags to smooth out the load.
Step 7 - Sand BackMy intention is to let all this dry, then sand back the exposed DivinyCell that remains above deck height.
Step 8 - Carbon WrapThen I will apply the exterior carbon layer without any external pressure, just careful 'stippling' with an epoxy soaked paintbrush to wet the carbon and ensure no bubbles are introduced.
Delamination
fixed
Gapping hole in nose
fixed
weak spot at front of nose
Expensive repair jobs are worth it!
White foam eski's come in very handy
Blue masking tape on carbon or glass fibre tends to pull strands out. Use sparingly or cut off just inside a tape line! 
"Bastard files" and spinning Dremel stones are good at removing glass/epoxy. Use VERY carefully. Avoid spinning wire brushes!
Carbon Mat is very thin. You don't need much of a countersink for a second layer. I went a bit too deep in hindsight. 
