Mast shifting at the bottom

Mast shifting at the bottom

Postby Wolle » Fri Apr 26, 2019 8:31 am

I bought a Freedom 39 recently and found the masts shifting at the bottom when at sea due to wave action. It is only some millimeters, but makes a terrible noice resonating through the hull. Sounds like someone is bangig a hammer on the hull.

How are the masts fixed to prevent them from movement? I can see only the bolts preventing them from spinning, although these are loose and cannot be fastend.

Any help appreciated.
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Re: Mast shifting at the bottom

Postby ketch22 » Fri Apr 26, 2019 11:54 am

Hello Wolle,

I am the owner of Ketch 22, F39 hull number 22. I bought her in 1997 near Houston. Shortly after, I sailed to Ft Myers Beach FL through short, choppy seas for hours on end. It was nauseating, but I didn't have the problem you described. Unknown to me the PO had put epoxy inside the mizzen mast at the base. It works like a charm - until you want/need/desire to remove the mast. The boatyard nearly had the hull out of the water before the epoxy seal broke loose.

I didn't have any trouble for years sailing in and around San Francisco Bay in all kinds of conditions. In 2004 I sailed to HI, enduring typical Pacific conditions. It was then that I realized why the PO had epoxied the mizzen to the hull. Downwind sailing brought out the noise that you described - but only in the mizzen. When I returned to SF, I built a frame to surround mast in two parts. I left room to pour fiberglass fortified epoxy between the frame and the mast. It worked great for about two years while I sailed through-out Central America for nine years in both Pacific and Atlantic waters. Over time, the epoxy surrounding the mizzen cracked and the fix failed.

After returning to the bay area, I've had time to think about the problem. My conclusion is that I should have used Spartite at the base instead of epoxy. This is as yet, an un-proven conclusion.

I never had the problem in the main mast. I'm not sure why, but it's not epoxy. Both masts were removed in 1997.
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Re: Mast shifting at the bottom

Postby Wolle » Sat Apr 27, 2019 2:14 am

Thank you very much for your quick answer Ketch22.

I'm wondering how this is meant to work by the boat designer.

Is there some kind of plug mounted to the hull which goes into the bottom end of the mast in order to hold it in position?

If someone has any pics, that would be great.

I'm also wondering how I can carry out work at the top of the mast without pulling the masts out.

I have a TopClimber, but don't dare to use it to the thin top?

Any advice in this regard?
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Re: Mast shifting at the bottom

Postby ketch22 » Sat Apr 27, 2019 12:46 pm

Not sure about the designer's intent. I never took pics when the masts were removed.

Regarding the mast work, I am about 190 lbs. I've been up both masts multiple times for different reasons. I use a top climber, usually with a safety line wrapped around the mast. The top climber line is tied to a solid point on deck. I use a separate line (used only for the top climber) tied (with a bowline) to the sail halyards (main or mizzen - not the spare halyards). It's worked fine for a couple decades.
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Re: Mast shifting at the bottom

Postby Grimsby_Alan » Sat Apr 27, 2019 10:49 pm

I’ll be at the boat in the next couple of days. I’ll take some pics of the mast foot pad. Can you forward me your email so I don’t have to fight the photo uploading feature here. I have a Hoyt 32 BTW but I’m sure it will be fairly similar.
1984 F32 Hoyt hull #41
Port Dalhousie, Ontario
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Re: Mast shifting at the bottom

Postby jamesorr » Sun Apr 28, 2019 12:03 pm

I believe the "plug" at the base of the mast is referred to as the "tap hat". On my F32 (Mull, 1988), it is approximately the diameter of the inside of the mast and approximately 3 inches in height, with a slot cut in it to accept the bolt which comes through the mast and would stop the mast from rotating (although given how tight the mast is held at the deck level, not sure how that could happen). When I first had my mast pulled, I wasn't sure whether the top hat had a slot or a hole for the bolt, so I removed it (a pain) before they went to lift the mast -- since it is actually a slot, that step is not necessary -- although one does need to remove it before the bottom of the mast can exit the deck level (so the yard lifts the mast a couple of feet, and removes the bolt before they lift it out of the boat -- reverse when re-masting).

I also have the original urethane wedge for the deck level attachment. It is one piece a bit short of the outer circumference of the mast at deck level -- and when properly fitted -- really stops ANY movement at deck level, and for my boat "HAS" to be removed before de-masting -- else, the boat will start lifting out of the water -- as my initial yard found out. Given I put my boat inside for winter storage (upstate New York on Lake Ontario), I have my mast pulled every year, and it really is a quick affair -- I undo the mast ring and tie it out of the way, they use a pry bar in the gap of the wedge (about an inch) to start the wedge removal, and then pull it out, lift the mast a couple of feet, remove the bolt, finish lifting the mast (guiding the mast wiring) -- their part of the mast removal process takes them 3-5 minutes -- a bit more to re-mast it in the Spring.

As far as the noise due to a gap between the outer circumference of the top hat and the inner circumference of the mast -- I did have the same problem (when sailing downwind) -- so one year, I measured the gap (with a decent set of calipers), which for me was approximately 3/16.'s So before they re-masted the boat, I built up a layer of resin approximately 3/32's in depth for a couple of inches up the inside of the mast -- haven't had a problem with mast noise since then. I also haven't noticed any additional issues with noise since I did the "repair" 4-5 years ago, although I might only get a couple of hundred miles of downwind sailing a year -- so YMMV...
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Re: Mast shifting at the bottom

Postby walterg » Mon Apr 29, 2019 7:36 am

Here's a picture of the mast step or "top hat" taken from my Mull 28 (not sure if the F39 is similar). As jamesorr notes there is a 1/2" dia by 10" length of SS threaded rod with a rubber sleeve over it that goes through the base of the mast and fits into the slot.
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mast step1.jpeg
mast step1.jpeg (81.36 KiB) Viewed 2080 times
Walter Gotham
Massachusetts USA
'87 Freedom 28-Mull #33 "Nova Vita"
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Re: Mast shifting at the bottom

Postby SFBaysailor » Mon Apr 29, 2019 10:59 am

Sorry for a bit of a threadjack here, but where do wires exit the mast(s)?
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Re: Mast shifting at the bottom

Postby Grimsby_Alan » Mon May 06, 2019 5:26 pm

On mine (F32) the wires exit through a hole in the side of the mast a few inches up from the base. The wiring must be tucked into the mast to fit through the deck then fished out the hole before placing the mast on the top hat.
1984 F32 Hoyt hull #41
Port Dalhousie, Ontario
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Re: Mast shifting at the bottom

Postby SFBaysailor » Mon May 06, 2019 7:16 pm

Got it. I haven't gotten up to the base of the main mast yet-I'm thinking I'll want to put a VHF antenna on the main and an AIS antenna on the mizzen. Sounds like I might be drilling a hole.
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