A sailboat project....thoughts?

[kwgeorge]

If you use wood check out Lignum Vitae as a choice.

Ken

[paulstenlund]

lcm - Landing Craft Medium?????? I have a Catalina 27 as well. We live on Puget Island in the Columbia River - walk across the back yard to the boat

Paul

[MikeR]

MikeR,

The last few years I have been crewing on a C&C35. I have been crew on all sorts of boats, C&C 39, Pearson Flyer, Tartan 30's, J36, and every June I do an overnight race on a J42.

Have you thought about a hard synthetic block of some sort? The repeating immersion and drying is a very hard environment on any wood. I would still be worried about the leverage on the bolts though. By the way, have you thought about what this added 1" will do to the rigging? Will your headstay even allow for the adjustment without raking the mast way forward? I'm not sure the 35 footer I sail on would have enough slack in the shrouds for an added inch of mast height. If it were me, I think I would stick to trying to fix this with a zinc and keeping the bilge as dry as possible.

~JRN

Yep, looking at a piece of epoxy laminate, waiting for the folks at West System to chime in. Planning on cutting the mast butt by the same amount as the riser. Relative position of stays, shrouds will remain constant.

The C&C 35 is a sweet boat. I sailed for years (did over a dozen Around Long Island Races on it) on a C&C34, my son has a j80 that I sail on when I get down to Annapolis.

Still thinking about the zinc thing. Thanks,

Cheers,

MikeR

[jrnewhall]

MikeR,

The last few years I have been crewing on a C&C35. I have been crew on all sorts of boats, C&C 39, Pearson Flyer, Tartan 30's, J36, and every June I do an overnight race on a J42.

Have you thought about a hard synthetic block of some sort? The repeating immersion and drying is a very hard environment on any wood. I would still be worried about the leverage on the bolts though. By the way, have you thought about what this added 1" will do to the rigging? Will your headstay even allow for the adjustment without raking the mast way forward? I'm not sure the 35 footer I sail on would have enough slack in the shrouds for an added inch of mast height. If it were me, I think I would stick to trying to fix this with a zinc and keeping the bilge as dry as possible.

~JRN

[MikeR]

More info

OK-

Mast is a hollow aluminium extrusion 5" wide by 9" front to back. It sits inside the oval parts on the photo attached.

My original plan was to use end grain white oak pieces glued together and sealed with epoxy and glass. End grain because its very strong in compression.

The photo shows a mockup. The plate is held down with 4 -1/2" bolts which are also keel bolts. Plan was to drill four holes through the end grain oak, then bolt the entire thing together.

Cheers,

MikeR

[jackellis]

I had the same thought as JRN. You might be better off with cathodic protection of some kind to deal with the dissimilar metal corrosion problem. Also, you don't say what the diameter of the mast is and whether it's solid or hollow.

[MikeR]

JRN- Interesting idea, never thought about the zinc thing. Yes there is the beginning of scalloping along the bottom of the spar.

Everything else being equal, I'd like to get the mast butt out of the bilgewater, having second thoughts about the oak and have contacted the Gougeons of West System about building a riser out of EGlass reinforced epoxy.

Will keep you guys posted.

What kind of boat do you race?

Cheers,

MikeR

[jrnewhall]

MikeR.

I've been racing boats for 20+ yrs and sailing all of my life. I've done my share of repairs on older boats over the year. Mast steps can take some very tough beatings in a all directions; tremendous compression especially if this boat has an adjustable backstay and considerable leverage side to side. Think of rounding up with the spinnaker up and the loads distributed throughout the rigging and down to the step as the spinnaker flogs the fills.

I wouldn't worry about redesigning the mast step. Besides, there are all sorts of other metals screwed into the mast and I don't think you can keep the mast dry. I think you should look at the electrolysis from a different angle. By the way, does the mast show signs of electrolysis? You could just attach a zinc at the base. You my want to check in some riggers reference but I think if there is a zinc in the water and everything is electrically connected, you shouldn't have too much of a problem. You just have to remember to replace the zinc every year or two.

~JRN

[big tim]

The reason I mentioned about endgrain is because that way more endgrain is exposed to water. It's my understanding that water enters wood more readily via the endgrain then through the walls of the wood fibres.
In wooden boat construction you go through great pains to avoid exposing end grain to water.
As I mentioned in my previous post you really don't have to worry about the compression strength of the wood. I'm assuming of course that the buttend of the mast has a metal shoe on it, distributing the weight rather than that rim of the mast is sitting directly on the wooden mast step.
Anyway my two cents worth.

Tim

[MikeR]

Hi Tim-

I wonder why you say that about endgrain? My sense is that that orientation is where the wood has the highest compression strength.

Northeastern boat builders (Pearson) did some strange things, like the steel mast step. On the other hand the glass work was tremendous. My boat, for example, has 1" laminate at the turn of the bilge an no core anywhere in sight.

Also, I believe that white oak is extremely rot resistant. At the place where I volunteer, Rocking the Boat (www.rockingtheboat.org), we've built 16 Whitehall rowing boats using steam bent white oak for all the structural components and they sit in salt water most of the time.

With thanks for your insights.

Cheers,

MikeR

[big tim]

mast base

I had to replace the mast sub base on my ketch this winter, not because of eletrolycis, but because of dry rot in the teak sub base.
I wouldn't wory about compression strength, but more about rot. I also wouldn't use endgrain. The teak sub base was in my boat for 22 years and there's absolutely no evidence of any compression in the old base. The boat is 40ft long and the mast is a heavy 55ft aluminum extrusion(11" x 7.5" oval in cross section).
The mast is stepped on the aluminum plate which sits on the teak sub base which sits on a very heavy fibreglass pedestal which in turn sits on the keel, no bilge water to wory about.
The picture shows the old teak sub base on the left and the new one in the middle.
I don't see anything wrong with what you are trying to do, other than that endgrain business. It would be nice if you could get that mastbase up more out of bilgewater. I'm rather surprised that they used a steel maststep. Maybe you can replace it with an aluminum one.
Good luck

Tim

http://i129.photobucket.com/albums/p...ift/Pic992.jpg

[lcm1947]

Yeah Mike I know the feeling about the mind willing but not the body. My wife and I are currently thinking about selling her, the boat not my wife. Sailing is a life style and you have to be willing to devote just about every free minute to it. So we are thinking about it anyway, but just one more summer of sailing sounds good to us though.

[MikeR]

We certainly enjoyed our visit and the racing.

I've got over 50 years on the water, loving every minute of it but have reached the point where the body isn't as willing as the spirit so will have to be content with sailing our own boat and not racing with the kiddies.

They live in Annapolis and trail the j80 all over the country to race it. They're leaving in two weeks for Key West Race Week. I've done it twice and can say that its about the nicest place in the world to sail.

I've also done a lot of work on C27s in addition to the 25s and 30s. They are terrific boats, very comfortable with a good turn of speed.

Will keep you posted and post some photos.

Cheers,

MikeR

[lcm1947]

J80, you said? Nice! Yes, we've sailed Lake Travis for 12 years now and she is a beautiful lake - and yes indeed deep although she's down about 30 feet right now. We, meaning my wife and I have had a 27' Catalina for the past 6 or 7 years and just about sailed Travis to dealth. Sorry if it seemed I was questioning your boating knowledge but I didn't know how experienced you were, but now I see that you're no newbie at it so yeah keep us posted with plenty of pictures please. Good luck.

[MikeR]

Unfortunately the boat has relatively shallow bilges and the small amount of water that gets in through the stuffing box settles in the way of the mast step. Just a function of the profile of the hull.

Cheers,

MikeR