Repair (bottom of boat centerboard trunk cracks and separation)

I recently repaired the bottom centerboard trunk with a fiberglass patch which separated after 3 days of racing. The patch separated causing a leak into the hull I removed the patches to allow it to dry and am planning on using west systems 404 mixxed with epoxy to fill the cracks, sand and place a new fiderglass patch over it. Any suggestions?

Re: Repair (bottom of boat centerboard trunck cracks and separation)

If you can post some pics, it would help us help you

Sounds like either the surface had some containaments, or there wasn't enough surface area for the repair to bond to.

I just got some pics. I have an ispection port next to the centerboard trunk it is still damp inside its been out of the water since friday, waiting for it to dry

It looks like the cracks at the front of the trunk are all the way thru the hull ? Are there any other cracks around other parts of the trunk (looks like something at the aft end of the trunk, but hard to tell ?

If those cracks at the front are all the way thru, it's going to take more then some bog in the cracks and a layer of glass on top - I would be putting in an inspection port and plan on getting a few layers of mat on the inside, and a few layers on the outside

i have 1 inspection port on one side of the trunk should i add another on the other side to access it easily? Also there is a piece of wood for support for the cockpit that is in the bow end of the trunk has another structural obstruction in the way which was glassed over but is now bubbily/flexy.

I'm guessing from your screen name you have a '75. I don't think the build specs have changed as far as around the trunk, here is a recent pic of the current process. That is a plywood stringer running directly down the centerline - It sounds like yours may be rotted and/or delam'd from the bottom. In order to really check, your need to feel around, feeling for movement, and pick at it with a sharp pointed object (knife tip) to see if it's solid or spongy/rotted. If it's either of those, then you'll should take care of this in addition to laying a couple layers of mat on the bottom and up the sides of the trunk. More then likely you'll need to add another port on the opposite side. If you can get a camera on the inside of the hull after it dries out, we can probably get a better idea and give you definitive advice.

While you are looking at the inside of the hull, it would be a good idea to check the conditon of the mast step - the plywood base and the donut

Here are some pics i took the wood is def delaminated gonna let it dry out then I will chk it out. The mast step was repaired and seems to be solid and the donut in in good condition compared to the stringer.

Thanks for all your help I am going to let it dry out durring the long weekend then get to work on it

Here's what I would be doing on the inside... (What's up with that shirt under the deck ?)

For sure thanks for the advice, the bow end is in better shape then the stern end of the trunk. There is a wood beem the supports the cockpit that is hard to access see photo but i will probably just hack the end off and do the same thing that you suggested me to do for the bow end. Thanks Again! oh and that Tshirt was just propping up my flash light and the boat is deckside down to get the moister off of the areas that need repair

lol about the t-shirt - I've found some strange items sitting in the hulls over the years, I was thinking someone forgot it many moons ago..

2 ideas:

I put a light bulb (old incandescent) inside to dry hulls. Be sure it doesn't touch anything or it may burn it. Sunlight on the hull is good also, as it might get to 100+ inside.

Also, that external patch may not have stuck well because epoxy doesn't bond to gelcoat. I can't quite tell from the pics, but you need to grind thru the gel, and epoxy to the glass/resin. If clean etc, that should stick.

Patching the inside may help, but since it's so hard to do well I'd focus on the outside patch.

Al

Thanks for the advice! light bulb sonds like a good trick to dry how long shoulde I keep it on in there?

laser75 said:

I recently repaired the bottom centerboard trunk with a fiberglass patch which separated after 3 days of racing. The patch separated causing a leak into the hull I removed the patches to allow it to dry and am planning on using west systems 404 mixxed with epoxy to fill the cracks, sand and place a new fiderglass patch over it. Any suggestions?

Click to expand...

hope you're doing well with your project. I'd like to ask you something. How did you manage to separate the centerboard and the mast trunk ?

I have similar damage close to the centerboard. There is a crack all the way through the fiberglass. I reinforced on the inside, applied gelcoat on the outside, but the crack reappeared after some hard sailing.

Is it necessary to remove the area with the crack e.g. by cutting it out? This seems to be the method described in most online resources. I prefer a less drastic method, but can someone explain to me how I can get the hull strong yet smooth if I apply an outside patch...?