1980 Hunter 36 mast step

[NY1T]

I decided to teach myself to tune my rigging. I get to the first turnbuckle and it is adjusted fully in. I had it looked at by a rigger and he said the mast step needs to be replaced.

When I looked at it, the piece below the floor, it is badly rusted. Odd the surveyor didn't mention it. Before I remove the wood around the post,

1) what does the step consist of?
2) where might I find/fabricate one?
3) What should it cost?
4) what is a reasonable price to get it replaced?

They quoted $1800 plus parts.

 

[rardiH36]

Dear NY1T:

Repairing the mast "sinking down" issue isn't a job I've done yet on my 1980 H36. It's still OK for me but I'm aware of the potential.

However, I'll make some observations which may help your quest for the eventual solution. Hope I'm not venturing topics you already know about.

First off, you've mentioned both "mast step" and "piece below the floor".

1) To my understanding, the mast step is the fitting into which the mast fits. As long as the standing rigging is applying enough downward pressure, this fitting, which on our boats is fastened onto the cabin top deck, secures the mast base so that the mast base doesn't slip around fore/aft/port/starboard or jump up and hence out of the fitting. Our Cherubini Hunter 36's have what's known as a "deck stepped" mast. Other boats, such as the Cherubini Hunter 37, have keel stepped masts. Even though the Cherubini 37 mast height from the waterline is about the same as our 36's, their masts are actually about 7-8 feet longer than ours because the mast extends continuously through the deck and "steps" onto the boat's very bottom above the keel -- rather than on the deck.

On our model, it is possible that years of water entering into the cabin top wooden deck core around the mast base will cause rot which would allow the deck step fitting to compress an inch or two on the deck. You would be able to see this as a distinct depression right around the mast base.

2) For deck stepped boats, below the deck directly under the mast is a "compression post" which extends from the underside of the deck to the bilge. The post transfers the downward pressure of the mast/standing rigging to the bilge above the keel. On the Cherubini Hunter 36's (or at least on mine), the compression post material is what looks like a standard piece of 3" galvanized iron plumbing pipe; much like I've got under my 1962 built house as the primary drain pipe. If the bilge is not kept dry, the bottom of this compression post pipe over time rusts and then can collapse a few inches. This is likely what is happening on your boat. On my boat when I bought it, by the water mark line in the bilge well, the previous owners allowed two-three inches of water to remain in the bilge at all times. The bottom of the compression post I expect was often wet.  I put in a small bilge pump at the very aft end of the bilge well that can bring the water level down to about 1/2" at the aft end. At the forward end of the well, I now have 0" at all times and the area is always bone dry. In the five years of my ownership, the bottom of the compression post hasn't really changed. Surface rust is visible, but by poking the bottom with a sharp awl, I've still got solid metal down there. So should be ok for a while yet. 

As to repair:

- Mast stepped boats are very common. If your deck area looks good, then the subsidence of the mast is likely due to the compression post base collapsing due to rusting away in the bilge. A search of this site or the internet should reveal compression post repair techniques. I have read that this usually means that the mast must be removed first. If my compression post ultimately goes, before going the professional route, I will be tempted to first to loosen the standing rigging, then use a couple of car jacks and a couple of 4/4's to see if I can "jack up" the deck enough to remove and replace the compression post. Rather than replace the post with galvanized steel, I probably would opt for a 4x4 piece of IPE lumber. IPE is used for high-end home decks. This stuff is rock hard (think 1920-30's airplane propellers) and is very resistant to water rot. Maybe I also would first soak the bottom end in Copper Green wood preservative for a few days to add even more protection.

- If your deck right around the mast base looks radically depressed, then its likely you've got some core rot in the area. The mast and the mast step fitting will need to be removed. The top skin gets cut away, the rotted wood core scraped out and then replaced with new material ... or even flood the area with thickened epoxy wood make the area even more solid and impervious to future rot? Then the top skin is replaced.

- Since the mast step fitting on our boat stays on the deck and is made of aluminum, I would think the actual "step fitting" condition should be good. However, a mast step that's in a bilge is a different story. The salt water can corrode them. A way's back one forum member posted in great detail about a neew mast step fabrication. I think in this case, the corrosion from bilge water also ruined the bottom few inches of the mast. The solution was very creative and done well. You should be able to search for the thread if interested.

Let us know how you get on!

 

[rardiH36]

After my reply, I remembered that I had a pic or two on my computer of my mast base area. Attached here in case you are not at your boat. The pics might help you "visualize" something.

 

[sarnold1119]

I rebuild the mast step on my 1977 H30C about 12 years ago, also replaced the left main blukhead. On the H30 the metal part in the bilge appears to be a piece steel I-beam attached to the keel bolts. Mine was low so I used high strength epoxy (40000 psi) to build it up. Also had a custom aluminum load spreading plate made for the deck. This operation required pulling the mast, compression post and the rotten bulkhead.

 

[NY1T]

Thanks for the replies and the nice description. So there is nothing special about the post. In Maine I would grab a piece of hornbeam. That stuff is tougher than a bag of hammers. I could likely do it myself with a 4X4. I have some railroad jacks that would easily raise the roof (so to speak). I am concerned as the turnbuckles were adjusted before I got the boat, so he may have resealed the deck.

I will look at it tomorrow and get some pictures for reference.

From your description, it would be similar to my 22 foot south coast. The deck hold the mast in place, but the post supports it.

Galen.

 

[NY1T]

I took some pics under the floor. Looks like there is a pipe with a metal plate on top. It appears to be compressed away from the floor.



The bottom of the pipe is rusted through and appears to be epoxied to the hull.




I don't see any reason yet to pull the woodwork around the post. There is sign of the mast collapsing the deck.




Not sure how the piece in the first pics gets replaced.

 

[RTB]

I have the same issue, and am working on a solution-http://forums.hunter.sailboatowners.com/showthread.php?t=125817

I am fortunate that there are no signs of a problem on deck, but with the rusted out post in the bilge, it's just a matter of time.

That flange which is kind of glassed(?) to the bottom of the floor seems ok. Just the tubing is rusted away. My thought is if I can glass in another piece of tubing, that will fit the OD of the existing tube, it might be an adequate repair....

Here is a rough idea of what I plan -

The area is hard to get to, and getting accurate measurements will be a challenge. Assuming the existing piece is some sort of steel (by the rust), I'm not sure what to use? I was thinking stainless, but that might not be a good idea?

I am thinking of mixing up some thickened epoxy to glue the new piece around the old one. Then use glass cloth and a bunch of epoxy to hold it in place. Providing I can find the right diameter tubing, and can get it fit properly, does this seem like a doable fix? Any better ideas out there?

 

[rardiH36]

RTB

For what its worth: If you haven't found it already, underneath the wood grate flooring in the head there is a square/rectangular piece into which the shower drain hose to it's pump is fitting. When this piece is removed (some screws and caulk hold it in), it provides a forward view access to the mast step area. Not sure if it will help your mast step beefing up idea, but I was surprised at the extra view/access when I removed my piece when I wanted to inspect the forward bilge area better.

 

[RTB]

Thanks, rardi. I will take a look under the grate next trip. If mine is as you say, that is going to be very helpful.

Ralph

 

[rardiH36]

At my boat after a week of heavier than normal California storms, I noticed water on the interior sole right at the base of the mast support post decorative teak cover. (i.e. at the bottom of the vertical casing in the attached picture.)

Likely water is leaking through the mast electrical wire opening. From the deck, at the base of the deck stepped mast, I could not find any spot to access the wire entry point to seal with caulk. So I need (I think) to get a better view from down below.

Has anyone actually removed the teak cover that conceals the mast support post? What's inside exactly?

 

[NY1T]

I took a 4x4 pressure treated post, 8 inches high with two wedge. I cut the 4x4 corners to make an octogon shape so it would fit in the hole where the pipe was. I gained a little height on the mast.

I will remove the mast, and open the post between the roof and floor to see what is there. I will get some pics.

 

[jphud]

I have removed the decorative molding on my 1980 H30. Be carefully and carefully score any finish treatment (varnish etc.) at the
joint gap which extends over multiple pieces of trim. This will help keep the wood from splintering. Once removed you should find a wood compression post.

 

[jphud]

The previous is with trim on.
This one is with one side removed.

 

[rardiH36]

JpHud:

Thanks for posting this. By your picture, aside from the compression post system, it looks like you've got a lot of other interior project work. Much different from my 1980 Hunter 36 where the original interior is still in wonderful condition.

Last week, after rapping with my knuckle the decorative teak that hides the compression post and also wondering what the screws under the bungs were biting into, I had a hunch that the post might be wood. Your pictures confirm that. So it seems that on our 1980 36's we have a wood compression post from the underside of the cabin top deck down to the interior cabin floor? Then a short galvanized pipe from the underside of the floor down to the keel/bilge?

The primed pipe in you picture will be the replacement for the wood post? What is the condition of your wood post? Sponge rot?

Again thanks for this info !

rardi

 

[jphud]

Wood post was fine. The metal post is the jack I used to raise up the post to replace the plywood under the compression post with marine plastic.

 

[NY1T]

I have replaced the metal piece under the floor with a 4x4 cut octagon shape with wedges to adjust the height. I didn't gain any height but now have support. I am going sailing in a few hours if the rain stops, then I will have the mast removed this week.

I thought while the mast is down I can add deck lights the the spreaders, and other work.

I think I need to raise the mast 1/2 inch to get the adjustment I need on the upper's turnbuckles. I am not sure where I would get that much height, as the floor looks flat and the jack (floor the roof) didn't seem to gain much (I loosened the turn buckles port starboard and aft).

The deck is sunk about a 1/4inch, but I am not clear on how the mast sets in the deck.

 

[NY1T]

I opened the post in the cabin. First I used a 1/8th drill bit to drill the plugs. Most of them came loose with that. The remainders I used a 1/4 bit and the plugs came out revealing the screws holding the teak to the composite post. Then I took the screws out of the aft 3/8 inch teak piece. It is exactly 75 1/2 inches tall. Therefore the height floor to ceiling.

The post inside the teak is exactly 5 inches square, the fist piece moving forward is 1 3/4 x 5 x 75 1/2. That piece is screwed to the next piece forward.

The next piece forward is one or two pieces ( not sure yet) with the starboard side cut for the 3/4 inch bulk head between the head any cabin. There should also be a channel cut for the wiring. It could simply be a 3 1/4 x 5 inch post with a 3/4 x 2 inch corner removed for the wire and bulkhead.

This setup leads me the wonder the bottom of the mast is grounded. If not, it may be possible to load as an antenna. The stays are grounded. The mast might too need to be grounded for lightning protection. Lights could ground through the stays.

I am wondering why a house jack post wouldn't work just fine though more may be required to support the door to the head.

 

[rardiH36]

Dear NY1T:

Sorry to be such a pain with questions about the mast step and compression post. But some maintenance/repair is in my future at some point. Your info has been great.

If you do unstep your mast, I will be interested to know what you see on the deck step fitting. In particular, how the mast electrical wires are routed through. After heavy rains, I have observed some wetness at the bottom of my decorative compression post teak where it rests on the the cabin floor. Most likely water is wicking along the wires and not making it to the bilge. It doesn't look possible to seal/caulk with the mast up. Over the long term, dry/wet rot to the wood compression post is a concern.

Also, how are the wires detached when the mast is removed because I can't see any opening on my mast to gain access to any uncoupling plug?

Many thanks.

rardi

 

[Ed Schenck]

A lot of deck-stepped boats require the crane operator to give you about six inches to reach in and unplug. When you lift it off the step I'll bet you won't believe how poorly that wiring was done. You will be able to make a major improvement pretty easily I bet and end up with a dry mast step.

 

[rardiH36]

Following this thread, I have been more concerned than in the past about the condition of my mast compression post system. Today I stuck a LED flashlight and then my generally unremarkable Blackberry smartphone camera into the forward bilge area where the compression assembly does its final resting place above the keel (at the bilge bottom). Pictures attaced. Compare this to NY1T's pics in post #6 of this thread. Wow! A big difference. Maybe its just a West Coast lower humidity thing. Or that previous owners NY1T's boat just let the pipe base wallow in bilge water for many years? -- or several neglected years of bilge flooding after a gulf coast hurricane?

Anyway, it looks like I'm ok for a while down there. I am tempted however to hammer-wedge a couple of pressure treated 2x4's (as has been suggested as a possible remedy to a rusting compression tube) between the the bilge base and the bottom of the cabin floor ... just to ensure that rust decomposition of the steel post won't cause settling some time in the future.