September 23, 2015-Chainplate Repair

wingssail images-fredrick roswold
Removing Shrouds

The last time we sailed in solid winds and big seas was when we were in the Papagayos going into Costa Rica’s Gulf of Santa Elena in 2014. The scenery rounding Punta Blanca that day was spectacular with the indigo seas slamming white spray high up the sheer rock walls of the point. The bright sunlight, crystal clear air, and deep blue sky brought a vibrancy and purity to the sailing. Bahia Santa Elena was in sight and we were in a hurry to make it to shelter in the strong conditions and we focused on working Wings upwind. We pushed the boat hard. In those conditions Wings blasted the waves aside and we took quite a lot of water on the deck.

Some of that water found its way down the starboard chainplate into the cabin.

Normally a trickle of water down a chainplate is no big deal but this water came in looking dark brown, like coffee, and it left a dark stain on the chainplate. This gave us some concern. Brown water coming from the vicinity of a stainless steel fitting like a chain plate is a sign of rust and possibly cracks in the stainless. Those problems can happen where the steel is wet and deprived of air (or more precisely, oxygen); it’s called crevice corrosion. In our case, where the chainplate came through the inch thick deck was where the stainless could be deprived of oxygen. The presence of salt in that water made for a witches’ brew.

Our chainplates are fairly new and beefy as hell so we weren’t immediately worried about them however the starboard one needed an inspection and we put it on the list. To inspect the chain plate we have to take it out of the boat and that means disconnecting all the shrouds. This is a big project and we have been putting it off for over a year.

Finally, Sunday night, I told Judy, “Tomorrow I’m going hammer and tongs on that chain plate inspection.” And the next morning I tore into it.

To take out the starboard chainplate you have to remove the starboard shrouds. That means loosening the starboard turnbuckles. You also must loosen the port turnbuckles because tension on only one side would pull the mast over and probably break it. There are four turnbuckles on each side so I had to loosen eight in all which is hard work and requires big wrenches. Also, this must be done gradually so as to keep the loads equal. First you do one side a little, then the other, then back, and so on. All together this took over an hour. Finally, before you remove the shrouds, you have to provide some temporary support for the mast. I ran halyards out to the sides of the boat and tensioned them. Only then could I pull the pins and bingo the chainplate was ready to be removed. Oh, you also have to unbolt it inside the boat, which I did, and then, it turns out, thanks to Sean Langman’s boys at Noakes shipyard who put these in a few years back, you have to grind out the fiberglass which encapsulates it. I did that too. And finally you use a 4 lb sledge to break it loose. All of this I completed by early Monday afternoon. I was sweating.

Now comes the important part; the inspection. The chainplate was covered in flaking, coffee colored, rust in the places where it could not be viewed and this needed to be removed before a thorough inspection could be completed. I put the chainplate down on the dock and hit it with the wire brush wheel on my grinder. Only then could I look for cracks. At first I didn’t see any, but looking closer I spotted one. A long, thin, horizontal crack, partially through the chain plate just inside where the deck covers it, was visible. It was surprising to me how such a small crack could make such an awful lot of rust.

OK, off to the welder at the top of the hill. Not that I like this guy’s work very much but he’s the only game in town and welding a cracked piece of flat stainless wasn’t exactly rocket science, so he got the job. Two hours and $25 later he gave me back my well battered starboard chainplate and it looked good enough to me, so before dinner that night, with Judy’s help, I put it back in. Not permanently, just with one bolt, but enough to hold it. We hooked up one shroud which gave us some comfort that at least the mast wouldn’t fall down if we had a squall during the night.

On Tuesday I replaced all the remaining bolts, filled the gaps with 3M sealant, attached all the shrouds, and re-tuned the rig, and we were back in business.

I’m pretty happy to have this big project off the list and really happy that I found, and fixed, a dangerous crack.

Oh, you might ask, “What about the other side?”

Well, no trickle of water and no brown stain so I’m not worried.

Click here to see more photos of this job.

Fred & Judy, SV Wings, La Cruz Huancaxtle.