Broken N20 Mast Base Casting

Hi all. Just purchased a 2001 N20. Had a question regarding a partially broken mast base casting. I don't have a picture at the moment but the damage is to one side of the casting. Essentially, one of the holes where the clevis pin goes through has broken off. One hole still remains. Is there any danger during sailing in regards to the mast getting knocked off if (when) I capsize or perhaps in strong gusts or maybe another condition?

I was able to step the mast down with no problem for winterizing this past weekend. It seems (from online research) that the two holes for the clevis pin are purely to aid in stepping the mast. But it would be nice to get some ideas from people more experienced.

Also, how involved is the replacement process for a N20 mast base casting if I decide to undertake that. Is it something that can be done by me or should I hire someone to look into it? I don't really have a lot of experience in boat repair.

If it's just the hole that the pin goes in, I don't think there should be an issue. It is not recommended that you sail with that pin in place, anyway. If the mast falls down while sailing (for some strange reason like a parted shroud or something), you don't want that pin causing more damage.

Under normal (and some not-normal) sailing conditions, the shrouds and forestay keep the mast in place if they are tensioned properly. Even after you flip, there is sufficient tension to keep that mast situated properly on the mast ball. I've never seen it come off unless something catastrophic happened first (shroud pin breaking, damage to main beam, etc)

If you're comfortable raising and lowering the mast without the pin (not recommended, but possible) I see no need to spend a lot of time worrying about it. The pin is supposed to keep the mast from slipping off that ball while you're raising/lowing it.

while you're on the topic, couple of things to check each time you're going to sail:

- all pins checked, secured with ringding and preferably taped in place. This includes shroud, forestay, bridle wire, and spin bridle pins)

- shackle at mast hounds (where shrouds and forestay meet at top of mast) is properly fastned so it won't unscrew and part while sailing (yes, it's happened)

- check the hounds where all the wires meet - sometimes that hole stretches out and develops a crack which might eventually fail

- shroud chainplates need inspection to see if they might let go. I don't know of any that have (for something other than the pin falling out)

Mine is broken

Just take extra care while lowering and raising the mast.

It was broken when someone used a screwdriver as a pin and it got caught in the crossbar slot while lowering the mast.

Don't ask me how I know.

John,

This past Saturday I looked at your mast bast. I think you will be fine sailing with it the way it is.

If you do decide to replace it, I don't think its a big deal. I replaced one on a 6.0 mast and it wasn't a difficult.

Heads-up, our fleet hold a party we call the Annapolis Invasion. Final details are being worked out. It will be a short notice announcment, since with our bunch that seems to works best.

The original mast bases on Nacras did not have the tabs for a stepping pin, they just had shallow sockets. To raise or lower the mast without a stepping pin, push the mast hard over to one side and keep a lot of downward pressure on the mast ball by using the tension from one shroud. No problem sailing without the pin. As another writer mentioned, it is best to remove the pin once the mast is up. Replacing a mast base is pretty easy. The base design has changed somewhat.

Speaking of mast bases, what's the "new" design for the N-20 mast base? I've heard of it, but haven't seen a pic of it.

It has a mount for the rotator arm.

Hobie-20 style rotation limiter? Anybody going to this set up? I'm looking at pulling the mast base off and cleaning some things up, was wondering if it was worth going to the new style at that point.

If you are pulling the mast base off anyway you might as well go with the new style rotation system.

I had one with a broken pin hole like yours. I stepped it that way for a couple of years before I finally sold it. I always tied a safety line to the dolphin striker and I had someone pull the mast base toward the ball as I stepped the mast.

Or just replace it. Anybody know if it's glued in or not? If it's glued in you might have a problem replacing it easily.

Mike Hill
N20 #1005

Actually mine's not broken, just some corrosion around the join, popping it off and cleaning it up seems like a good thing to do. Didn't know if anybody was actually using the new system and whether they liked it for this boat. Tying the limiter to the boom makes it somewhat self-tending, but the mast base system would be simpler and takes some crap off the boom.

Keith,
I switched to the rotator on the base a few years ago and love it. I had a big grommet added just behind the halyard pocket for the rotator limiter line. I did it pretty much Hobie 20 style. It adjusts much easier and will over rotate much easier when setting the spinn.

Lee - did the grommet on the tramp interfere with the snuffer line/grommet at all? Also, are you still using the lines/cleats on the boom/mast to force/lock the rotation? Thinking back to H-20 days and the bungee system to force rotation, with the limiter keeping it in check...

Less force is needed to induce rotation. The angle of the mainsheet blocks is pretty good, so when you sheet in, it pushes the boom forward naturally. It actually over rotates easier without all that line running through the blocks in the cascading system. My retrieval line grommet is just off to the left and right behind the halyard pocket with the rotator grommet centered behind the pocket. I simply drilled through the base and added the rotator arm like the 6.0 was, only with the arm facing rearward. The new base actually puts the arm a little further back. At the time I did it, Nacra didn't have the new (or old for that matter) bases available, so thats why I used an old style base.
You may want to add a small piece of spectra to hold the arm up off the tramp like the H20 did.
I do still use the cleats on the boom to lock it over in distance reaching with the chute.

With the rotator at the base there is a pretty sweet posi rotator system... works much better than the boom idea...
Got this idea from Mike Krantz...
A few inches inboard of the jib cleats put a cheeckblock on the top of your beam... in front but a bit out of line (so it can stay uncleated) put a cleat... repeat on the other side.... tie a line from the end of the rotator arm, by the cleat, through the cheek block, across the front beam, past the mast base through the cheek block on the other side, by the cleat and tied to the rotator bar again.
You pull in on the windward side and cleat it off.
My boat is inaccessable to take a pic but i've really liked this system.

A pic or a diagram would be cool if you can! I've been thinking of ways to force the rotation without the usual boom cleats, this sounds hopeful...

Keith,
The N20's mainsheet blocks hang from the boom to the rear cross beam at such an angle that when you sheet in, it forces rotation by pushing the boom forward. The F18 is more vertical and pulls more down than forward. Anything more complicated isn't really needed.

I think I need that system. The boom mounted rotation inducer is the only bad part of the boat. We often are racing in light airs and the rotation inducer is needed.

I guess everyone keeps missing the point. WITHOUT all the cascading line from the boom mounted rotator preventer, the mast over rotates EASILY and EFFORTLESSLY.

Lee I don't know about yours... but my mast doesn't (or didn't on my 20) rotate 90 degrees in light light air with the chute up and the mainsheet eased

I apologize for the rudimentary drawing.. I am at work and didn't have much to do it in.
The red is the line. I use a 3mm dyneema line, no need for a big line.
Put the cam cleats just slightly outboard of the cheek blocks so they will not cleat by accident.

Todd, you need to get back to us with a better drawing, that one wont do.

Understand/know the geometry thing. It stands to reason it happens easier without the lines all over the boom/mast. Still seems like you need something to lock it in, or in some cases force it, depending on conditions. Although effective I dislike the lines on the boom to force/lock rotation. Was starting to think of something like Todd is suggesting. Sounds like it's time to change the base and experiment!

I guess I should have added your-milage-may-vary to my earlier post. I could use that thing upwind and downwind...

Lets talk about doing this . . . AND other stuff...maybe tonight, not today off to the WH, hopefully will still have my head...

Agree. After seeing Todds diagram, I like the idea better than the boom thing.

Yah mon. We can talk about it, I've got a dealer I'd like to give some business to, we can place the order for the castings together. It'll make the boat easier to rig/derig too...

It's really a good system.. It actually locks the mast over... not like that crappy on the boom system.
Keith... I have a friend that just move down to Naptown his email is stephen_metzler@yahoo.com
He's interested in crewing and etc.... he's a good sailor, he's from my hometown of Madison, CT where we have a 30 boat catamaran fleet. He's working for Atlantic Spars.... He has a Hobie 18 "Mild Thing" that formerly belonged to Joe Manganello.
It'd be great if you could drop him a line and get him involved.

Will do. We're always looking for fresh blood, and he can bring his 18 to play! Atlantic spars might be a good connection as well...

Just a follow up here. I got the new mast base. It has a place for the rotator arm, and the pulleys for the bottom of the downhaul as well as for the main halyard. Adding this can clean up a whole bunch of stuff. My current retrieval grommet is centered behind the tramp pocket - I'll use that for the rotator line and add a grommet a little to the left for the retrieval line. The only thing is that the new casting has two large holes underneath it. One would be for the Infusion internal diamond adjuster, not sure about the other. I'll have to seal those. Anybody actually ever pull the mast base off of one of these things?

Why?

It shouldnt be the same base as the infusion as they have different profiles. Check to see if you got the right one before you bust up your other one taking it off.
Also, there is a plug in your mast just above the rotator arm bolts.

Dealer said the same casting is listed for both Infusion and 20 (which sounded odd but I went for it anyway). It looks right (and same piece comes up with a picture on Murrays), but I'll do more inspection before drilling any rivets. I was wondering if there was a plug. I may still seal the holes.

Chris - if the mast is unsealed at the base it would certainly fill if the boat went turtle. I can also think it would help the mast fill if there were a leak near the top.

Your mast should have a small (pin hole sized) hole in the very bottom of mast (aft end) this is a drain hole for your mast. Plugging this hole is not a good idea. If you do get water in your mast, this is the only escape point.

Got a small hole on the front of the mast for that, it's plugged unless I need to drain. The new mast base casting has two large holes in the bottom for internal diamond wire tensioning (not used on N-20). I'll be squirting some goo in those as well.

Ok - Pulled the old mast base out. Lots of corrosion and goop. If you want to use all the features of the new base, you need to trim away some of the sail track (about 2"). So far I've gotten everything except for the clam cleats off, have trimmed the sail track, made some epoxy repairs, cleaned off a lot of old crap. The new base fits well - this is going to look/work nice. It does sit lower on the mast ball though.

So - there was no plug. I kind of get the feeling that maybe the base has been off once before. It seems to have just been sealed with run of the mill silicon, but there was some evidence of some other sealer from a distant past (was white, kind of looked like maybe 4200). So I'm on the fence as to what use when I put it in. Regular old silicon? I also have some silicon/poly sealer, I have some 4200. Not sure what to use. Any opinions?

I believe you, Mike, are speaking of the boat that I still have -- Poison Girl. I kept on using it with one pin hole broken for years and it was never an issue. I replaced it last year, but when I went to step it the pin slipped, got caught in the crossbeam slot, and popped the hole open again (lesson learned!). So I'm still sailing with one pin hole and it doesn't make a lick o' difference.