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Open heart surgery


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So the Winter repairs begin.

This years task is... open heart surgery to the under side of the starboard deck between the chainplate and the rear beam.

There is some delamination in there that needs some attention.


2m of Carbon Fibre - 12k Weave, 200g/m (this is 12k http://heroman.us/uploads/allimg/100925/1-1009251350358.jpg)

1kg Vinylester Resin and hardener

.5m of chop strand fibreglass

500ml Polyester Resin and hardener

2 paddle pop sticks


Cut an oval hole out of the inside of the hull above the deck join through an oval hole, sand out the de-laminated section, clean it up with some 80grit.

2 maybe 3 layers of the Carbon on a 45degree bias, laminated with the vinylester and cured. There is a possibility i will put some stringers in to stiffen the deck further.

Then to close up the hole, glue 2 paddle pop sticks into place on the inside of the hole with polyester resin. Once cured put 2layers of chop strand around the inside of the hole and tape the plug (cut out originally to gain access) back into place. Once that is set, use a fibreglass filler to fill the gap left by the saw cut and glass over the top of the filler to get a strong join. Coat with white flow coat and sand with 2000 grit then polish.

Sounds easy enough but we'll see.

I'll take photos along the way.

Work commences on the 13th Aug, should be 2 weekends work to let everything cure properly.

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From what I read you might encounter two issues, one that carbon has different characteristics to glass so you'd be putting different stresses on the repair (plus you may need a little flexibility at that point). Second everything you read talks about epoxy being superior to poly, you're glueing onto poly which is a mechanical connection not a bonded one. Apparently epoxy has better grip (providing you prepare the surface properly).

Jimmy Buckland supplied me with some mat which had about three axes and was quite thick. Seems to have worked well on the repair I did to the keel line of my Careel. On that I used a flappy wheel on a grinder to strip off the gelcoat (about two metres took ten minutes!), then the mat in wide strips (3) using baking trays to hold the epoxy.

On the fixit section of Sailing Anarchy there are a couple of guys who regularly monitor and contribute who work at West, very interesting comments.

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I love vinyl ester and find it very predictable for going off. I only find Wesystem reliable in summer and if it doesn't go off when it should, I have waited many days for it to go off. Theres something about UV rays When I use vinylester I put the repair in the sun and can wet and dry 1 hour later.

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I read as much about Poly, Epoxy & vinylester as I could.

I ended up ringing FGI and talking to their tech guy, because some say epoxy repairs on poly is good but others say it won't adhere. He said epoxy won't bond to the polyester well and I should use vinylester. They have all 3 instock and epoxy is more expensive so based that he sold me the cheaper vinylester I come to the conclusion that it is unbaised expertise.

I don't forsee any issues with using the carbon, i've done it before and seen it done by professionals without problem.

I don't understand why I would want any give in the deck. Its a structural part of the boat so I'd like it as stiff as possible.

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You've done well in talking to the experts on this. Vinylester is the best for this application. Poylyester is crap - brittle, low adherence and best used to make things which can be heavy with no strength. Not a good idea on boats unless you want to live in the 70's. As mentioned above, epoxy is good but more expensive and a bit more sensitive to humidity and temperature. Different mixes are used in various parts of the world to take account of climate - also summer and winter. carbon is probably a bit of overkill in this application but of course has the bling factor - any issue with class rules? It is not too good with impact and not strong in compression. The inside skin is where you need all the strength so it may be OK. Normal e glass would probably be just as good though on this boat.

Sounds like a nice easy fun repair. Good luck.


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I know carbon is overkill, but i'd prefer to not have to do this repair again and the 12k 200g/m mat was only $30/m not $70+/m.

The inside skin of the deck should really only see tension not much compression so carbon works a treat. The other option I had was kevlar but i choose to do it in carbon.

No class rules issues as they dont make mention to hull materials except production form. This is a repair not an entire hull. Also this repair will add weight to the boat not reduce it so no issues in using carbon. We also have factory carbon cross bars these days so the material is used elsewhere.

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Michael is talking about his Windrush.

I was talking about my Careel because I had some serious cracking happening. Yes they're not the same, however the competition is just as hard.

If we were talking about top fuel dragsters then Michael should be using vacuum bagging in a temp and humidity contolled environment.

By the way if the windy rules are the same as the maricat (which of course they're not) I think hull material is indicated - probably by reference to manufacturers choice.

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Surgery went well.

3 layers of carbon fibre now laid. The section i laid goes from the side-stay chain-plate to about 80mm in front of the rear bulkhead.

I was surprised to learn that the deck is not a full foam sandwich. There is a piece of foam that covers most of the inside of the deck and then a small strip down the outside of the deck. But there is alot of area that is just fibreglass.

All that is left is to close up the hole next weekend.

Will post a photo of the hull insides soon.

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Hi Michael,

did you take any more before, during and after pics , would be interested to see the repair in progress . Have a friend who has the same problem with his WW & I know it was one his list to do over winter (bet it hasn't been done yet! ). Will pass on your info to him.


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I didn't take any before shots... i forgot...

Its an easy repair though and I was surprised that the fibreglass looked in quite good condition inside, no obvious signs of delamination. Its as stiff as a brick now though and I probably only added 1kg to the hull.

I cut an oval hole in the deck underneath the tramp track about half way between the sidestays and the rear beam.

Sanded out the majority of the glass that covered the upper deck foam. I had to make 2 foam sections to fill the profile between where the foam stops on the upper deck and the dip is for the tramp track (I did this so the carbon would have a better chance of adhering as it wasn't about to follow the tight contour)

Then I laid in the 3 layers of carbon with the middle layer being on a 45 degree bias. Resin of choice was vinylester.

We've stuck some paddlepop sticks to the inside in prep to close up the hole.

All up it was about a days work to get this far. O and a hairdryer comes in quite handy when its 16degrees...

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  • 2 weeks later...

Well it's all done and dusted now!

The hole is faired and painted and i did the tramp tracks as well this weekend so watch out my boat is going to be in tip top shape come the first day of the season.

Hull weights are 26.5kg ea (they were 25.5kg ea in 94), only 1kg of weight added since new so im quite happy given they are 17yrs old!

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