Goosneck corrosion - how bad is this?

[giogi93]

Ayo sailors, I am somewhat of a beginner, tormented by the galvanic corrosion at the goosneck.
I need a bit of your wisdom:

- Is it still sufficiently safe?
- How urgent is it to repair?
- What would you do?


For context, the boat is a small 22ft, used mostly in inland waters and sporadically along the coast.

 

[PaulK]

The problem looks like it is mostly with the boom's end fitting, which has cracked. The other corrosion doesn't look like it has impacted the structural integrity much. Finding a new piece will be a problem for something as obviously old as this is. Taking it apart to fix it might be possible, but you would need the new part to replace it, so... poor ROI. Since it is relatively small and transportable the best bet might be to take it to a shop that welds aluminum and see if they think adding a bead to the crack and joint would firm things up. If so, let them clean it up a bit and have at it. The loads on a boat of this size are not huge and you could also simply sail the boat and monitor the crack to see if it gets worse. The sail, sheet, and vang should keep things manageable until you get back to port if it does suddenly let go. But then you'd have a broken boom.

 

[rgranger]

Are there any indications of who the manufacturer was? It might be a stamp or a sticker on the boom or mast?

If so, it’s very likely you can order a new end cap. look at the out haul on your foot of your main sail… if you have a few inches to spare there, then go back to the gooseneck take a hacksaw and saw off a half inch or so put the new endcap in and you’ll have fresh clean metal that’ll last you another 30 or 40 years.

 

[dLj]

- Is it still sufficiently safe?

Hard to say, but given where and how you are using it, I'd say yes.

- How urgent is it to repair?

Looks like a great winter project.

- What would you do?

I'd take lots of measurements of the sail and boom. How much extra room, if any, at the end of the boom do you have? If you cut the end of the boom back, can you cut it far enough to get back to good metal and still have enough room to get the sail in the sail track and have enough boom left to fully stretch out the main sail? If yes - cut it back. If no, see how far you can cut to get the majority of the corrosion removed. Can you find a used boom in decent shape? Might be easier if you can do that and of course if it doesn't cost a lot.

If rebuilding - Take the whole mess apart. Might be fairly frustrating to do so.

See exactly how that broken part was manufactured. Try to find a replacement - if not possible, have one built. When reassembling - isolate all the stainless contact points with tuf-gel and reassemble...

dj

 

[rgranger]

You could build a wooden boom.... that would look very salty.....

Here are some plans I found online ... I'd go with laminate cedar and spruce strips for extra strength and then make the center hollow to keep weight down.

How to Build a Wooden Mast - Mastering Skills with the WoodenBoat School

ISLA, New York 32 No.10 (of a total of 20), was thoroughly rebuilt by Buzzards Bay Yacht Services of Mattapoisett, Massachusetts. The job included a new mast, whose construction is detailed on the following pages.

skills.woodenboat.com

Spar Building

The mast support came out very well so it is on to the mizzen mast. The top section of Skorpa'a masts are hollow wooden spars sheathed with ...

sundogboatbuilding.blogspot.com

 

[giogi93]

Thank you for all these different angles, much appretiated!
I will try to sort it during the winter break.

The boat is from the 70's and the manifacturer is out of business, so sourcing parts is not simple... Taking the whole mess apart is indeed a frustrating scaring prospect...

1) Cut boom and replace the fitting --> Will an average workshop do a custom made new fitting if I bring the sliced out piece of boom for measuring?

2) Patching crack and pitts by welding --> brilliant, will inquire

3) New boom --> The sail has slugs along the entire foot, sliding on a track in the boom. From a fast search, I could not find new boom profiles compatible with that, with most new stuff having only a skinny grove for a bolt rope foot . Am I maybe missing the right keywords here?

 

[dLj]

Thank you for all these different angles, much appretiated!
I will try to sort it during the winter break.

The boat is from the 70's and the manifacturer is out of business, so sourcing parts is not simple... Taking the whole mess apart is indeed a frustrating scaring prospect...

1) Cut boom and replace the fitting --> Will an average workshop do a custom made new fitting if I bring the sliced out piece of boom for measuring?

2) Patching crack and pitts by welding --> brilliant, will inquire

3) New boom --> The sail has slugs along the entire foot, sliding on a track in the boom. From a fast search, I could not find new boom profiles compatible with that, with most new stuff having only a skinny grove for a bolt rope foot . Am I maybe missing the right keywords here?

Yes - not an easy project... It will be hard to find a new part to go in - if imposible. It will be hard to find a used boom...

I would not cut the part out of the boom first, I would try to remove it by drilling out all the rivets holding it in. If You can't get the part out and you have the room to cut the boom back, then you might make that cut and peel off the part of the boom over the end piece. But I wouldn't cut first, I'd try to remove that part first.

dj

 

[rgranger]

Most likely your mast was built by Kenyon Isomat. Rig Rite might still have parts from them. They would need to see the profile of your boom's "hole".

Go to this page and look at the boom profiles and see if any match your's.

Rig-Rite Booms Page

If so, you can just call Rig Rite and talk to someone about a new end cap (assumeing you have enough room to cut) or if needed order an entire new boom and gooseneck.

If Rig Rite does not have what you need, you might also check Dwyer Mast & Rigging - Quality Sailboat Parts and Rigging

 

[PaulK]

If you are able to dismantle the boom end pieces you might be able to make a replacement boom end fitting out of a block of wood. The piece is really only a plug at the end of the boom that you could shape out of a piece of oak, maple, or even Douglas fir. You could hold it in place with screws instead of rivets. The stainless plate would then screw into it on the end too. Not overly difficult.

 

[heritage]

If you do decide to replace the boom, I would not use the old slides, but do a "loose footed" attachment of the foot of the mainsail to the boom. Just cut the slides off the sail.

.

 

[thinwater]

I didn't read whether there is extra boom length or not. If yes, this is pretty simple for a machinist, even an amateur. A few hours.

The fitting is stainless, bolted to an aluminum plug in the boom. I would cut off about 1.5 inches of the boom, then cut just behind the SS fitting to free the bolts (probably seized). I would then cut a new plug on a band saw from ~ 1.5" aluminum plate (or two thinner sheets more likely) to fit in the boom. Then relocate the fittings, perhaps with a few added machine screws to secure the plug.

The curves of the cast fitting need not be replicated.

A portable band saw with a stand and table make it pretty simple.