Hobie cat 18- Leak in swivel draggerboard trunk

Hi everybody !

I live in Mayotte a small island in the Mozambique canal between Madagascar and Mozambique.

I bought one of the only Hobie 18 formula (1991), with swivel draggerboard, part of the rare hobie cats on the island.

It was in a bad shape so I spent the last 5 months to renew it entirely and got my first boating yesterday.

I had great fun... The trade wind starts blowing on the lagoon !

Unfortunately... when I tried to bring the H18 back on the beach... I felt it quite heavy...

I opened the drains plugs and a lot of water came out of the port hull... A bucket at least !

As I pickled entirely both hulls to recover them with 2 thickness of fiber glass with resin and gelcoat, I assume there is a leak from the inside of the draggerboard hull.

It can't come from the rudder holes as I put off the old gudgeon to put the fiberglass and dig new holes, filled with sica mastic glue before fixing new gudgeon. It can't come from the drain plug hole. Even if there was water in the bucket of the trapdoor, it doesn't explain how the water came into the hull.

Thus... I am looking for your advices !

- Did it already happened to you ? Is this a recurent leak trouble on H18 ?

- What should I do ?
... open the trapdoor ?
... disassemble the hull from the crossbars to check it ?

- How can I dectect the leak location ?
... Fill up the hull with water ?
... Fill up the swivel draggerboard tronk with water ?

- How can I repair the tronk ?
... from the inside of the tronk with fiberglass and resine ? How to prevent from draggerboard fiting after repairing from the inside of the tronk ?
... from inside the hull by the trapdoor with fiberglass and resine plus gelcoat ?
... from both the inside of the tronk and the hull ?

I wish I don't have to disassemble the boat and create a new trapdoor...

Looking forward to read from you,

Sincerely,

Dam

First thing to do is confirm the location of the leak.

Fill a spray bottle with water mixed with dish soap.

Then lightly pressurize the inside of the hull. The easiest ways to do this are to either place the exhaust of a shop vac “near” the drain plug hole, or shove a length of rubber hose into the drain plug hole and blow air into the hull with your lungs. It does not need to be a lot of pressure.

Then have someone go around the hull and spray all the suspect locations. Wherever bubbles come out, that’s where you have a leak. After you know the leak location, then you can figure out the best way to repair.

sm

As usual, SRM is dead on. I have used "Dawn" brand dish soap to check for air leaks on many things. air lines, tires on rims, anything that may be leaking, OH and yes,,, these Hobie Hulls.... (the mast gets this treatment too)... whatever really soapy, bubbly, mix you can make up will work, as long as it is easily water soluble. don't use bubbly stuff like armorall, or any kind of silicon based chemical.
Finding the leak is only way to fixing it...
i have purchased and use a cheap wi-fi camera to my smarty fone.. it is self lit and stiff enough to reach kind of far into my '18 hulls. maybe an option for you as far as seeing the leak in real time?
sorry if not applicable for you, but, it is sunday nite here, and i wanted to be on the internet.

Hi guys !

Thank you for your answers !

Monday was public holidays... So, I couldn't wait and decided to fill up the hull with water... salty water...

If water can come in thus it can get out !

Good news ! I found a very small leak from the draggerboard trunk and 3 others from the crossbar fixation.

As I put 2 more thikness of fiberglass, I had to sand the hull in order to fix the brace in the gutter.

Thus as the leaks couldn't explain why I had so much water in the hull, I believe it could come from:
- drain plug not enought tighten
- trapdoor joint to old

Effectively, the trapdoor join is little beat to old.

So I am waiting for the hull to dry in order to fix everything.

The call of the sea will have to wait for a few days !

Sincerly,

Dam.