New Bobstay Chainplate Design

Hey Guys,

My good friend Rosie (matt rosen) finished up the technical drawing for my new bobstay chainplates last night. I dropped the drawing off at the fabrication shop this AM. I posted some pics in the gallery and a short write up on the blog. Thought you guys might find it interesting to see what I finally decided to go with.

Now, time to fill in the gap in the bow left from the old design.

Looks great! Will even look better finished in bronze!

After looking at your photo gallery I’ve decided that my bobstay fitting in incredibly under built. It is nothing more than a beefed up wisker stay held on with 2 1/2" bronze bolts.

So I have to ask the question, why go with something other than the standard SLM fitting in bronze? Are traditional looks making the decision for you? Or are there other reasons?

Great photo gallery by the way. We’ve been keeping up watching and getting ideas from your photos.

Wow, great pics of your refit! Intense stuff - when did that all take place?

I decided the glassed in bobstay fitting was a good solid design, but preferred something i could see all the time, and wanted to go bronze. Was really 6 of one half dozen of the other IMO… so in th end it came down to wanting something traditional, and wanting to “put my mark” on her. I wasted alot of time on this 'lil project, overthinking it and worrying about wut to do.

Wow, I finished all of your pics jsut now… intense! Excited to see more…

What did Todd say bout the bobstay design?
You mocked up the tank dimensions?
CPES - im diggin that stuff, I guess you do too :slight_smile:

It’s a process that’s for sure. We hauled in January and I intend or relaunching in Spring of 2010. Gives us plenty of time and lots of time for the boat to dry out. Getting ready to re tab all existing structural bulkheads this weekend. My goal is to have the Settees installed by our wedding on Sept 6th for viewing. We’ll see!!!

I took a trip to Port Townsend with all of my parts, questions, and money in hand. I was going up to buy the engine mount and an 8’x8’ piece of that cool gelcoat grooved paneling on SLM boats. The bobstay was immediately questioned by everyone that looked at it, Todd showed us how they were installed on their various Cutters in the yard. I got home about the same time you were posting your pics so it was nice to see that better. I phoned shortly there after but Todd left to the East coast for a bit and will be back in the middle of August. So I’m expecting to have the bobstay by October. I would use Pete at PT Foundry but I’ve found working through Todd is faster with more assistance.

The tanks were made by me again after visiting Todd and looking at the construction book on the stock water tanks. I have lead shot and pine tar mixture for ballast. The ballast sits taller but is about 1.5 feet shorter, forward/aft, than the cast SLM ballast. My ballast ends at the forward face of the rear settee/chart table bulkhead instead of going back to the oven area. The problem was the large belly tank that fits over the ballast is too tall and the 24 gallon bilge tank leaves too much room in the bilge for…??? So I designed my own tanks out of cardboard to fit in the bilge from the back of the ballast to the front face of the engine mount I bought from CGC. Together they are roughly 55 gallons. Tripple M Plastics is on it and as a matter of fact should be shipping them out to me tomorrow. Man I hope I didn’t mess up measurements (I measured 4 times…).

I also just ordered the B125 Ronco tank for the waste forward since I removed my samson posts anyway and can redesign from the bottom up.

CPES is amazing stuff. I took a lot of time researching the stuff and finding lots of + and even more - to it but my general overall opinion is nothing but positive. Goes on easy, absorbs VERY well and is hard and ready to prep in about 3 days at 75 degrees. I let it sit for a minimum for a week before touching it. I’m currently drilling messenger holes around all of my existing holes on deck to make sure the core is dry and will soak in acetone then CPES before final filling.

Over thinking, I think, is just a part of boat-building. I did the same with my water channels for my lazzarette hatch. Spent about 20 hours just on that little thing and a lot of epoxy.

Be interesting to see your bobstay when finished! I like the traditional look to it. And your wire rigging makes me jealous. I REALLY want to learn how to do that but would want someone knowing looking over my shoulder just in case.


Bryon & Maria
CBCC Cosmic Dancer

Yeh CPES is cool, but just takes a long time to dry and you can’t rush it… sometimes i dont have the patience!

Spliced rig will look nice, im a little nervous about it, but im sure it’ll be fine… however ill keep an close eye on it for any signs of uneven tension on the wires around the outside of the thimble… that’s the issue. I was supposed to serve the wire around the thimble…oh well…live, mess up and learn. Wish i was able to pull test them to destruction… would like to know the numbers on that.

Regarding the bobstay chainplate design i went with… here’s a little story about castings, that reinforced all the words of caution i’ve heard about their reduced strength compared to machined bronze pieces…

We were raising my friend Teresa’s mast on her Nor’sea 27 yesterday, and I was loosening the headstay to allow more slack in the backstay so we could attach it to the chainpates aft… I kept loosening it, until I heard a frightening “BANG!”. The rig shook. I stopped. I looked at the turnbuckle on the headstay and realized i was tightening the headstay! Oops. Afterwards, we discovered what the bang was… it was the cast bronze pad eye on the aft rail used to attach the main sheet (you use the main sheet to raise the mast). The eye had snapped on one side and was opened up. I had no idea how tight I made the headstay, but i was REALLY surprised that bronze fitting broke. I’m not sure what direction the pull on it was when it broke - perhaps it was getting torqued in a weird way… but in any event, no one got hurt and the mast didn’t fall… so we’re lucky.

But I guess it’s just a heads up about bronze castings, and their strength. I’m curious to see what the foundry says about it when we bring it in for a replacement, if there is anything they can tell about the casting by the way it broke. And I’ll be sure to keep a better eye on which way I’m turning the turnbuckles from now on!

Never heard of that but I will defiantly bring that up when I talk with them about the part.

We’ll let you know how it turns out!



benjiwoodboat Wrote:


But I guess it’s just a heads up about bronze
castings, and their strength. I’m curious to see
what the foundry says about it when we bring it in
for a replacement, if there is anything they can
tell about the casting by the way it broke. And
I’ll be sure to keep a better eye on which way I’m
turning the turnbuckles from now on!

Ben Eriksen

Yes indeed. Here in Belfast we just recently had a launch of three 1902 Herreshoff Buzzards Bay 30’s beautifully restored by a fine local yard. They used a subcontractor for cast bronze fittings and have had some very unexpected failures. I saw one jib clew hook casting with a partially separated stress crack, a very granular look where it was starting to come apart. I don’t think there would have been be any way to visually predict the potential problem, they were beautiful castings with perfect surface finish. It all comes down to knowledge, care and experience and one must depend on the qualifications of the foundry doing the work. I’ve never heard a bad word about Port Townsend and expect that they or any foundry experience in marine work (very different from fine art casting!) wold be willing to discuss strength requirements in some detail. Even a “forged fitting” begins with a casting, so the specific alloy and it’s subsequent processing are what counts.
Good luck!

Yeah Scott, seems like you really are at the mercy of the foundry and their quality control methods. G&B uses a foundry in Boston for all their castings, and so far so good. That place is called Mystic Foundry in Somerville. Upon further inquiry with Nor’sea Yachts, we discovered the parts were ABI made, and can be bought from Jamestown Distributors for $12.00, which to me seems curiously cheap.

I got the new chainplate mounted, well almost… haven’t bedded and tightened it yet, but drilled holes and got it in position. It fits really well, suprisingly! Take a look at the post here:


The bobstay tang looks great - “built stout.” Instead of ordering new bolts, cut the bolts to size and file the end, such that nut threads on easily. I do this all the time.

Rosie did a nice job of fabricating the tang.



Looks great! I almost wish I had one.

Just got mine from CGC/PT Foundry. It’s not what I had envisioned but none the less I intend on using it.

I do have a question that you or someone else on here might have. Do you know the angle from the bob stay to the bowsprit? All of the pictures I have on this type of bob stay have it positioned higher on the water line than my original bobstay. Looks like the

Attach and go right to post!

anyway… looks like the bob stay in the above attachment is quite a bit higher, by some 3" or so than what I “normally” see on BCC’s

Thanks for the help!



Subject - Padeye, Nor’sea 27

If it is an ABI casting, it is probably leaded red brass cast in China. I trust Chinese castings about as much as I trust their dairy products. This is the reason, we purchased Crosby red pin anchor shackles made in the U.S.A.

The brass shade on our ABI cabin reading lights split open in several places after 4 years. I do not purchase ABI products anymore.


I don’t have the angle measurements for the bobstay, we just did it with the bowsprit in place and got it close to where it was before. Mine is higher then it used to be now by an inch or so, for no reason in particular. I haven’t put my spliced bobstay in place yet… hope it fits!! Douglas has that same cast fitting on his BCC, check with him for more info if needed. I know he backed it up pretty well to spread the load.