Well Dennis wasnt bad here in South FL, except for some strong wind gust. Some trees down, specially that branch that fell ON MY CAR! although that would entitle another post not related to catsailing.

Here is my issuse at hand. Aparantely the wind was strong enough to drag my boat, several feet crashing it into a trailer parked next to my boat. The end consequence is a 6" gash that goes all the way through the hull. How would you attack this problem?
Photo 1
Photo 2
Photo 3 In this photos seems like only gelcoat payed the price.
My plan is to get some west marine epoxy and some density filler and patch her up. One thing is I do not know how to start or even deal with these type of problems.

Would you expoxy? Or Fiberglass? I do have experience working with fiberglass and epoxy. Enough to where I am confident I can repair this problem, with proper instructions or recommendations.

I am hesitant to drive it up to Vector Works Marine, because that would involve 16 total hours of driving.
Plus doing repairs on your own boat is half the fun.

What would you folks do?

Get a good glass man there are many mobile craftsman driving around.They come to our beach all the time. Thats to bad Robi.Was your boat on the ground or on its trailer and crashed into another trailer? That cut has to be cleaned up and strengthened from the inside out.If there are no inspection ports in the deck you may have to add one

With regard to the epoxy / polyester question - use epoxy. Epoxy adheres well to cured polyester (even better than polyester does). HOWEVER, polyester will not adhere well to epoxy - and gel coat is polyester. If you intend to gel coat, repair the boat with polyester resin.

That said, you should find a good glass guy - that's going to be a pretty tricky repair. I'm no expert but I've done a good bit with fiberglass in the past (vacuum bagging, mold making, etc.) but I would probably take it to someone. Sorry to see that.

So you guys definitely recommend getting it professionally repaired. If that is the case, I will take her to VMI.

Does not look like a particulary big job to fix that hole. Make sure you get the boat off the beach or cover it over to keep the sand out, then :

Here are some general instructions for fixing holes and the like (written for fixing H16's and Dart 18 keels to ask questions if you have any):

1, clean out all cracked gelcoat; remove all the fibers that look like they have dirt/grime in them; remove any soggy glass matt (it probably won't really dry properly). Basically remove all the old/damaged areas and make sure you have a clean area to repair. This could mean removing some of the Keel line and having a "Slot" down the middle of the boat. (NOT IN THIS CASE)


2, Make sure everything is clean and dry - VERY VERY important - you can use an Acetone to really clean it and a hair dryer to make sure it is dry


3, If you have an empty slot (if not go to 8) you need to build a backing plate (Thin Balsa can be good for this and then put some string thru it so you can pull it snug to the INSIDE of the hulls by putting your mold thru the slot you have made by cleaning out the old/damaged area and then pulling back snug (this is where the second pair of hands becomes useful !


4, While someone holds the string (and so mold) snug to the inside of the hull, apply glass mat and gellcoat to the hole/slot you have made; Ideally you want to get at least one layer of mat on the inside of the hull - Tip:
Stick the Matt (and gelcoat) to the balsa/cardboard; then put the sting thru and then put this inside the hull and pull it back so the matt sticks to the hull inside. Now while "String pulling mate" holds the string you need to gaffa tape the sides of the hull into the right position so that then the matt sticks it will hold the hull in the correct shape. - This for fixing Keel line cracks on boats like Hobie 16's and Dart's

Basically here you are getting something into the holl and behind the hole so that you can build up layers against it.


5 Let this cure; you now should have a trench that you can fill up and return the hull to the right shape


6, At this point depending on the size of the void left :

7 Big void - long or wide; I would fill this with gelcoat mixed with chopped strand mat (very hard when it goes off) or use gel mixed with Micro ballons (less strong) and then move onto


8. 8 small - Just use filler

9 Top tip 2; when you are getting close to the correct level/shape of the hull; use "grease proof" cooking paper as a outside skin as this will allow you to get a good finish before you need to start standing

10 once you have filled the hole(s) up you need to sand back to the right level; use 400;600 and 1000 wet and dry and then polish if required


So you will need

Acetone (check which one) - some melt gelcoat
Gelcoat of the appropriate colour
Glass mat (depending on the scale of the repair)
Mixing pots for gelcoat - paper are best; just throw away after Mixing sticks - I use wooden sticks you get for coffee at Starbucks and the like - might need a spatula for gelcoat when mixed with chopped strand glass.

Robi,

Fix it and sell it... Number one must be bad luck for you.

Scooby Simon, excellent write up. Doesnt seem to hard according to your post. I am going to get in touch with Matt McDonald to see what he recommends. If I repair it, and it voids my warranty I just may NOT go that route.

You are correct and it has run through my mind.

That's a very sad sight Robi, but dont despair! I have seen much worse stuff repaired.

Ref: http://www.nt-tornado.de/fotosspektakul%E4r.htm
(pictures taken by the Mittelmeyers, german T team)

Scooby's description is the way to go for fixing the long rift. I would not have used gelcoat (gel?) as a filler, but regular epoxy thickened with chopped glass strands or collodial silica.
The key is the use of a backing plate to re-build the inside skin. Without an inside glass skin, you will not get a good repair.
When cleaning up the area, cut a bevel all around the rift and sand down the edges to make room for some new layers of glass without ruining the fairness of your hull. After the rift is filled, cover it with some staggered layers of glass (ask Matt about what cloth to use and how many layers)

If you need it, you can make a mould from your other hull, but on a small job like this I would not have bothered with that. Feel, some careful sighting and a smear stick should be good enough to restore the fairness.

The other damage looks like you only need to sand, fill, fair and paint. Should be easy.

If you decide to do this on your own, take care to protect yourself from the diverse chemicals used!
It's a good idea to contact Matt anyway, check what he would reccomend for repairs.


Bad luck having number one?? No, but there might be some issues that need to be sorted out, as always on a new product. But this doesn't happen due to the boat being number one. Repair it, paint it and get on the water again, it will be just as good as before..

Sorry to hear it too Robi,

A 65 kg platform will fly away in a storm, you don't need much wind for that. (I trust you had removed the mast from the boat prior to the storm) It is not like it sits tight on the beach like a 130 kg F18 platform and even these need tying down in a blow.

Really sorry to hear this,

Good luck,

Wouter

Sorry to hear about your damage, and with those nice new graphics, too! jimbo posted a three part article on foam core construction repair over at the beachcats Yahoo group.

Part 1
Part 2
Part 3

And an ad for repair work in central FL.

You have to be careful when doing a repair to advanced composite structure that you use materials and methods that duplicate as best as possible the function of each layer.

The cloth used to build a high performance catamaran is definitely not the same cheap $hit cloth that they sell at the local boatyard or auto parts store. Those junk open weave cloths are prefectly fine for repairing stuff built with a chopper gun, but they will result in a repair that is very resin-rich and brittle. Try to find out what cloth style the boat was built with and use that or something close. Failing that, use a good quality aerospace/industrial grade like 7781 or 1581 cloth. Do pay attention to fiber orientation and alternate it between layers(0-90, 45-45).

Likewise for the core material; don't install a substitute core that is like 10X harder and stronger that the original foam core. You will just make a stress concentration point that will probably crack later. A very dry mixture of resin and plastic microballoons should do nicely. Avoid chopped strand in the core substitute as it will make it too strong.

Many sailors avoid boats with repairs since most repairs have a bad track record on longevity and they typically cause the boat to be overweight. This is because the above guidelines are often not followed. In aviation, we return busted advanced composite parts to original form strength and weight all the time, so it can be done and actually does not take any more work, just a little knowledge.

Also use a piece of thin(.024") 2024-t3 aluminum for the back up plate for the repair. Since it is so thin, you will not have to widen the hole to get it inside the boat like you might for a balsa back up plate. It's important to use a structural grade like 2024-t3 for the backup plate, too. The non-hardenable architectural (junk) grade they sell at the local home centers are too soft and weak to be useful as a backup plate. The difference here is dramatic, not subtle. You can then pull pretty hard on the wires attached to the plate and force it into good contact with the curved inside of the hull without the backup plate breaking or the wires pulling through like it might with balsa.

Other than these little details, Scooby's tutorial is spot
on, so just follow that while observing the above and your boat can be the equal of new in strength, form and weight.

Jimbo

Jimbo,

Without going to great lengths with etching primers and such, resins (epoxy or esters) don't adhere well to aluminum which could possibly leave the aluminum plate swashing around inside the hull. Secondly, even if they DID manage to adhere well, the aluminum would have much different flex characteristics than the surrounding fiberglass. I would personally stick with the balsa.

These are good points, but already taken into account. I did not mention surface prep for the backup plate since I expect it will fall off shortly after its usefulness has expired, thereby obviating the worry about a stress concentration. In a saltwater environment, the aluminum will not exist for long as a piece of sheet metal anyway; it will turn to mush. This is especially true for the structural alloys like 2024. This is one reason they like architectural 5052 or 5056 aluminum for 'tuna towers' on fishing boats; it is itself FAR more corrosion resistant than 2024, and we haven't even touched on anodizing. 2024 is NOT anodized. Weight does not matter that much to power boat builders; if it did, they would not build those boats with a chopper gun.

I don't think any one will notice if a little piece of aluminum weighing perhaps a few grams is down in the bottom of the boat for a short while, assuming it is complelely unretrievable. There's no engine to make it rattle, after all

Jimbo

If you have never done a repair like this take it to someone who knows or get someone who knows to come over and help you.

If your boat was older you could experiment.

Robi we do repairs like that one ever second week during the racing season. From what it looks like in your photo's its no where near as bad as rips we see from start line "bingles". Any decent fibreglasser should have absolutely no problem at all in making that repair back to as good as original with no visible signs that it was ever there. Just one small recommendation, don't use epoxy resin, the hulls are, I believe laid up with vynalester resin for the blade, so do the repair with vynalester resin and finish with polyester gelcoat, that way there is complete compatibility between materials.

I feel for you Robi,

Even though F18s are quite a bit heavier than your rocket ship they are certainly not immune from ground loops on the beach when it really howls. Here is mine after we righted it - bust spreader, spin pole and bent mast courtesy of a steel picnic shelter + a wild north front.

HUH!! Duh!! where are the photos flumpmaster?? (or was my mother right ? I did go blind)

Thanks guys for the replies. Too many folks have recommended me to go to a repair shop. Not only here, but the composite guys at my job as well.

So I will look for a local fiberglass guru and have this chat with him.

Hi Robi,

just found your post sorry to see it. Don't worry mate, it's just a flesh wound, compared to what happened to Altered, it's no problem. I would get it fixed proffesionaly though, mainly because the finishing off is a absolute bastard. Pro's will make it look just like it did before, you have seen Altered and it had the bottoms cut off never mind the break right around the hull. Gee I have sailed boats with that sort of damage with a bit of tape over it.

But I know how you feel when it is new it just breaks your heart, so get a Pro on to it and you will never be able to tell it happened, Insurance should cover the cost anyway.

Regards Gary.

Whoops - I put in a local address to the server by mistake.