Saturday, August 31, 2013

Daggerboard Trunk Repair and Leak Test

Our Sunfish Madison had damage to the daggerboard trunk on the hull, gelcoat was chipped and a previous owner had repaired the area with epoxy. The epoxy had flaked away and we could see exposed fiberglass, still encased in epoxy but the last layer of defense against leaks. We didn't notice any leaks but wanted to check for leaks and repair the area.

From Small Boat Restoration 2013

We did a leak test with a mix of dish soap and water, recommendations say 50/50 but that seemed like a lot of soap to me. We put about 1/4 cup of soap with a gallon of water and it was plenty soapy. For the leak test you blow air into the hull vent hole, which is located on the forward wall of the cockpit. The key to putting air into the hull is to use very low pressure and very low volume. You can blow air into the hull, use a bike tire pump or a compressor set to low pressure. CAUTION: if you put too much air into the hull you can split the deck/hull seam or inflate the boat enough to break the foam blocks loose. Then you'll have more repairs! Blow a little air into the hull, stop and put your hand by the hole to see if you can feel the air coming back out.

From Small Boat Restoration 2013

From Small Boat Restoration 2013

For this leak test we put the boat on its side and drew a soap bubble across the top and bottom slots of the daggerboard trunk. We also soaped up the inside of the trunk. We were looking for bubbles around the openings and also to see if the bubble over the trunk openings grew. There are a lot of static bubbles from the soap mixture but it will be obvious if air is escaping, a large bubble will grow or so will a bunch of small bubbles. For our test we found no leaks in or around the daggerboard trunk.

From Small Boat Restoration 2013

From Small Boat Restoration 2013

We did find leaks around the halyard cleat and the inspection port!

From Small Boat Restoration 2013

Once we were done playing in the bubbles we washed off the rest of the boat and mixed up a batch of epoxy putty to repair the area. Some people use plain epoxy, we like Marine Tex or West Marine RX epoxy putty because it comes in a small size and it is colored white, which matches the Sunfish white gelcoat pretty well. You can find epoxy and gelcoat kits in your local marine supply store, also online and at my local Ace Hardware store. Amazon has a good price if you are thinking ahead :)

From Small Boat Restoration 2013

We use a low tech paint stir stick broken in half lengthwise to apply the epoxy, that we we can reach up inside the trunk if needed. The inside of the trunk often has epoxy chips that expose the fiberglass and also gets damaged during groundings.

From Small Boat Restoration 2013

From Small Boat Restoration 2013

We want to remove excess putty so we dont have to sand it off later. You can use a plastic putty scraper to smooth out the surface a bit, or a good ole finger. Another trick is to put wax paper over the putty, smooth it down then remove the paper.

From Small Boat Restoration 2013

We mixed up the entire 2 oz of putty, so we looked for other gelcoat chips to repair. This area has impact cracks in the gelcoat from being struck by a very solid object. The cracks are in the gelcoat and not through to the fiberglass, so they can be left alone for now, we will keep an eye on them. Madison went through several hurricanes stored outdoors, notably Ivan and Dennis, so there is no telling what all she stood up against. After the putty dries we will sand off the excess.

From Small Boat Restoration 2013

Once the putty dries we use a 4 in 1 file to knock off the excess and get the repair moderately smooth. I like this file because it can be used for rough and moderate filing, and it has both a flat and half round side, perfect for the sides and ends of the daggerboard trunk. A friend uses a power drill with an extension bit and sanding drums, we may graduate to that next. I do the final sanding with a power sander in the areas I can reach.

From Small Boat Restoration 2013

From Small Boat Restoration 2013

From Small Boat Restoration 2013

After sanding I applied some Interlux Brightside Bluglo White. It will darken up after a little time.

From Small Boat Restoration 2013

Repair is finished and Madison is ready to sail!

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