Tuesday, April 16, 2013

Sinking Boat Averted

Back in October of last year, I finally broke down and decided to replace the thru hulls and old gate valves. After removing a couple of them I realized how badly they really needed to be replaced. See that post here, http://svvita.blogspot.ca/2012/10/the-sea-cock-debacle.html .

Well, we finally got them all back in, and even added one for a raw water intake. The plan is to put pressure water in the boat using the manufacturers installed system, but taking the water from outside. This new thru hull also happens to be the size needed if we ever decide to install a water-maker. I know it sounds like a bad idea to add another hole to the boat, but with the gear we just installed, I don't feel that it is an issue, this stuff is tuff. 

The original water intake for the head. Small plywood backer, simple thru hull with a nut. The 4200 gooped all over it is probably the only thing that kept this from blowing out of the hull.
New water intake for the head. Fibreglass backer supporting the whole seacock, fibreglassed into the hull. Bolted to the hull in three spots, and a proper thru hull screwed into the unit. Incidentally, the two 1/2" seacocks for the head and engine raw water intake are made of Marelon. Without getting into the big marelon vs bronze debate, these were the ones available to me, so these are the ones I used. All my research seemed to find no flaw with the fibre reinforced composite material (marelon). The point though, is that the new one is tough as nails. Especially when compared to what was there.
There are instructions on the internet, http://www.pbase.com/mainecruising/replacing_thruhulls , this guy did a good job on the how too. He uses a flanged adapter with a ball valve, but a full on seacock would be tougher; no exposed threads.

I made new base plates by laying up fibreglass resin and cloth to a depth of 1/2". Then I cut the different sizes needed for each seacock. Somehow screwing up the count. I had to cut a single 6" disc from a piece of fibreglass I removed from the boat, but it worked fine. I ground out the area around each plate, because the paint they put in these boats is some kind of epoxy, and I am pretty sure the fibreglass won't stick to it. Then Serena and I glassed these discs into the hull using "bondo - short hair" filler and  little plexiglass stabilizing discs I made to keep the outer-hull and the plate aligned and parallel to one another. Then I redrilled the holes to accept the thru hull.
 The galley drain thru hull didn't work out so well due to an really uneven area of the hull, and installer error. So I had to cut another plate from a piece of fibreglass cut out of the boat earlier, and install it over the first one. This ended up being about 1 1/4" thick.
On the outside of the boat you can see how the bolts attach the body of the seacock to the boat. Tough..... Each one of these bronze bolts cost $7, but one with a normal hex head instead of the tapper head was $3.50. So I bought the hex head, and took the grinder to them. Ta-da, money saved. The holes are countersunk, and althought I didn't take a picture, I covered them over with epoxy.


Engine raw water intake and starboard cockpit drain looking for a thru hull.
 These discs for the cockpit drains are 6" in diameter. They are big, the picture doesn't really show the size.

The head sink drain got the old fibreglass plate, but it was the easiest one to install, go figure.
New 3\4" seacock and thru hull.

 And below is one of the original cockpit drains from when we bought the boat. With a picture of the new ones above. One of these things is not like the other!!
So glad to have this done. Now to get the rest of the pre-launch jobs done for first lift in 11 days and its currently raining.

Cheers and fair winds.

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