Thursday, March 4, 2010

Boat Work Goes On Forever

The past few days I have spent a good bit of time doing what I seem to do most on board Arden, and that is work. Mostly it is work that is making forward progress, things that have been on the to-do list, and sometimes new things that just crop up from an idea or a whim. Then of course there is basic maintenance, and that is constantly on going. And cleaning, seems like I never catch up or get ahead, but I do what I can to stay on top of it.

Yesterday and today I have spent most of the day working on getting my chain plates to seal up. For those not familiar, a chain plate is a flat piece of metal, normally stainless steel, that is bolted to the boat and connects the standing rigging (the stays and shrouds to the mast) to the hull. On Arden there are 6 chain plates, 3 per side, and of the 6, 2 have been consistently leaking since I launched the boat. Talk about an on going project. Last year I tried to rebed them (caulk them and make them water tight) but my efforts only worked for so long before the seep returned and I had a mess inside my cupboards. I even went as far as taking the Dremel Tool and routing out a new area around them and then using 5200 caulk, but that lasted only so long as well. Then a few months ago, well heck close to a year ago, I saw an article in Good Old Boat magazine that had one guy's fix to this.

On a lot of boats the chain plates are mounted outside the hull and bolt through to timbers on the inside, and I had considered doing this to Arden. It is a lengthy and involved job, and I decided to try the method described in Good Old Boat first before I commited to making that undertaking. Arden is set up like most boats, the chain plates go down through the deck in a slot, and the slot is cut a bit larger than the metal of the chain plate itself. This extra room allows for caulking compound to be squeezed in, and theoreticly that will keep any water out and the boat dry. However, all of this is subject to a lot of factors, expansion and contraction of the various materials, the bond between the caulk and the hull, and the caulk and the metal. It doesn't help when the chain plate goes through a low spot on the deck that seems to always trap water, and this is of course where these 2 leaking chain plates are located.

So here is the fix. You build a raised area on deck, around the chain plate, that will keep pooled up water away from the deck penetration, and shed off rain water at the same time. How do you accomplish this? By building forms and pouring epoxy into the mold you have created.

To prepare the hull for this process I first removed the shrouds from the 2 chain plates in question. Then I removed the escutcheons and got down to the deck. I dug out all the old caulk, and then began the surface preparation. The bond between the new epoxy and the deck is key, and so to make sure I had a good bonding surface I sanded the deck and the bulkwark with 50 grit sand paper. I removed the paint and made sure to take the sanding well into the gel coat, there needs to be a very clean and rough surface for the epoxy to adhere to. Once the sanding was done, I drilled out the old screw holes for the escutcheon plates, and then vacuumed away all the dust and debris. Once that was done I wiped the entire area down and cleaned it up with acetone.

After clean up was complete, I laid out how I wanted the new bases to be formed, and marked it all out with a permanent marker. I then got out some modelling clay I had gotten a year ago for this expressed purpose, and sliced it into 1/2 inch thick slabs. I also cut off a slab that was about 1/8 of an inch thick, this I would use to create the caulking groove around the chain plate. In the article in Good Old Boat, this entire job was completed on a boat where the rigging was removed and the chain plates were being replaced. On Arden I could not take the time to remove the chain plates, so I made a slight adjustment to how the job was done. I wrapped the chain plate with a thin layer of modeling clay, this would provide the area where caulk would be applied once the epoxied areas had cured. Next I made a form, or mold, out of the modeling clay, the idea here is that the clay is strong enough to hold the epoxy, easy to form and work with, and once the epoxy had cured, it could be removed easy enough.

I made the forms so that the poured epoxy would make a raised area around the chain plate about 3/4 of an inch thick. This would now move the joint where the chain plate penetrated the deck up out of any standing water. I also tapered the form so that there would be a slight angle on the top of the raised area that would help drain water away from the joint. Once the forms were complete, I mixed up the epoxy. I used West Systems epoxy for this job, I have several different brands of epoxy on board, but I wanted the cure time to be fairly quick, and the West stuff was the only epoxy that I had fast curing hardener for. I do not particularly like using West System, it is supposedly the best, but, it has a mixing ratio of 5 to1, that is a real pain in the posterior when you are using measuring cups and doing it all by hand. For work such as this I much prefer MAS or Systems Three, both of which use a 2 to 1 ratio, that is easier to mix and a bit more forgiving if the ratio is a drop or two off. Once the epoxy was mixed up I added in a bit of chopped fiberglass to the mix to give the epoxy some strength, and I also added some Cabosil to it to thicken it up. Until it hardens epoxy is like wet concrete, it needs a thickening agent added to it to keep it from running or slumping. The Cabosil is a silica based powder that thickens epoxy much like flour thickens gravy.

I poured my epoxy concoction into the molds, and made sure to press it down into the holes where the screws used to go into the deck. I used a small screw driver to do this, pushing the epoxy in and making sure any trapped air got out. I then smoothed the epoxy, and waited for it to dry. And waited. And waited a bit more. I am not sure if it was the outside temperature, or if it was because my resin was old, but it took forever for the epoxy to set up and dry. Once it did harden though, the end result looked pretty good. It took a bit of work to get the clay off the chainplate and out of the slot for the caulk, but in the end it was not bad and could have been worse. I mixed up another batch of epoxy and filler to make fillets around the new pieces, this will help move water away from the blocks and blend them into the deck and the bulwarks.

Now it is time for paint and caulk, and the job will be complete, and hopefully, I will have a boat that is a bit drier now than it was before.

I spoke to David Schaake this morning, he and Peg are still here in Ft Lauderdale aboard Journey, looks like if I can get my sails done in time we may head to Bimini together, they are waiting on a few things and the right weather window, and I am doing the same. Our plan is to keep in touch over the next 4 or 5 days and see if we can't both be ready to go at the same time. I sure would like to hit the islands before I sail north, would kind of really cap off this trip.

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