Several months ago, I talked about filling in holes in Daydream. I patched two thru-hull openings, one for the overboard head discharge and one for a redundant transducer thru-hull.
Now that the entire boat, inside and out, has been sanded and the first coats of paint are being applied, it’s time for me to actually start making some holes in the boat, or at least remaking some.
A Columbia 26 has two deck drains and two cockpit drains, one of each on each side. Both drains on one side of the boat meet at a tee at the top of a seacock which in turn is fastened to a thru-hull. The old drains were pitted and dull. We decided to remove them temporarily to make painting the deck and cockpit easier.
Removing the drains was easier than we thought as they disintegrated in our hands. The thru-hull had a plywood donut under the thru-hull, but the plywood had rotted to the point the only thing holding the thru-hull in place was the old sealant, not a good thing.
The good news is that the sealant was still effective and had bonded the thru-hull to the hull itself. The bad news is that we had to remove the thru-hull to replace the donut and clean up the hull around it, both inside and out. A few minutes with the angle grinder and a big hammer soon had them out of the boat.
A search for replacement drains turned up few options. Nothing like the originals is available, probably a good thing seeing how they disintegrated. We were also concerned that the drains were a little undersized for the size of the cockpit and the amount of water it could potentially retain.
So we decided to up size the drains, seacocks and thru-hulls. This meant the existing holes were now too small and had to be opened up. My favorite tool for this kind of job is one I put together myself, in whatever sizes needed.
I stack two different size hole saws together on the small center drill. The smaller, inner hole saw is the size of the existing hole and serves to center the combination. The outer hole saw is the diameter of the new hole size.
With this tool configured to the required sizes, it was simple to open up the existing thru-hull holes in the bottom of the boat.
The deck drains were an entirely different matter. The new deck drains are very much larger than the originals. This wasn’t a problem in the cockpit as there was enough room around the existing hole to accommodate the new, wider drain.
The new deck drain hole would have to be off-center from the existing hole, meaning my stacked hole saw tool wouldn’t work. In a case like this, the hole saw needs something else to keep it running true. It is normally guided by a centering drill or other hole saw but neither would work in this situation.
Luckily I had some StarBoard polymer lumber left over from cutting out the new electrical panel. I took the hole saw sized for the new hole and drilled a hole in a piece of the StarBoard. I left the hole saw hang over one side of the StarBoard. As long as there are more than 50% of the edges of the hole left, the hole saw guide will properly center the hole saw.
I marked the deck with the location of the new hole and held the guide block in place. StarBoard is slippery stuff, so I added some double back tape to the bottom side of the block to help hold it in place.
I used the guide block to keep the hole saw centered in the new opening until it had cut through the deck. The result was a new hole properly offset from the original, smaller hole.
The next job was to make the new donuts for mounting inside the hull, through which the thru-hulls pass. The donut helps stiffen the hull and spread the load, from opening and closing the seacock, over a wider area. Often these are made from plywood, like the originals on Daydream. However, they do have a tendency to deteriorate over time.
I decided to use some more of the StarBoard off cuts from the electrical panel. I had purchased a large diameter hole saw for installing solar vents a while back. The hole saw turned out to be the ideal diameter for the outside of the donut. I was able to cut the donuts out using my 18-volt battery powered drill. I didn’t try to use the stacked hole saw tool on this job as the 4 plus inch diameter hole saw required all the power the drill could muster.
Once I had the donuts cut out, I C-clamped them to my work table and drilled out the center hole. The result was four perfectly formed thru-hull donuts in about an hour and a half.
The last major project on this hot summer day was reconfiguring the holding tank. Daydream didn’t originally have one but we wanted to add one. Careful jiggling spaces allowed me to use a nine gallon tank. It will be mounted on a shelf, just below the deck and behind the head itself.
Space is tight and there wouldn’t be room for the tank to be installed in its normal position. That mounting position is with the openings at the side of the tank. The upper inch and a half opening is the inlet, the lower one the outlet and there is a five-eighth inch diameter vent line opening, on the same side as the other vents.
My installation required that the tank be stood on end, with all the openings on top. This worked fine for the inlet and the vent, but not for the outlet.
Luckily Todd, the manufacturers of the tank, also have available a kit for relocating the inlets and outlets. And, guess what, it required making more holes in the tank,
The new lower drain was a standard acetyl plastic thru-hull fitting. It would have to be inserted from inside the tank and the nut screwed on from the outside. This required an opening large enough to get my arm inside the tank. The Todd kit included a four inch diameter access plate and ring.
I traced around the access plate lid, which was the same diameter as the access plate ring mounting hole. I drilled, with a small hole saw, an access hole to insert the blade on my Bosch saber saw. The saw made quick work cutting out the opening.
I put the access plate ring in the opening and used it as a guide to drill the six mounting holes for the access plate fasteners.
The only thing left to do is to install the drains, thru-hulls and access plates with 3M5200. I’ll wait until painting is further along to do those installs. I want to be able to economically use a full tube of the 3M5200 sealant.
Two hole saws configured to widen an existing hole.
A new deck drain hole, drilled off-center by using a guide block.
A StarBoard thru-hull donut.
The holding tank showing the added access plate and lower drain fitting.
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