Banging inside the mast

Hello Freedom owners. After a few hundred miles of upwind wave bashing in the caribbean i woke up at a rolly anchorage to to a loud banging noise from inside the mast of my 45. Its not wires, or cables, its something solid and metallic. It sounds like a door slamming. Its cant be good for the mast: any idea whats in there, what it can be?

Are you sure it is inside the mast? If so, how high up? I bring this up as it is not unusual if there is any gap where the inside of the mast mates with the top hat at the base of the mast, as it moves slightly based on wave action, it can make very unnerving noises. A number of solutions are available to make this problem go away by reducing/eliminating the gap.

Unnerving is an understatement. Mine sounds like someone is banging the mast with a ball peen hammer. It is a horrible and very loud noise!! If the anchorage is at all rolly polly that might be the answer. However, mine only acted up off the wind in a good seaway.

The upwind bashing may have loosened the base up a bit. It is just a tiny movement BTW. Very hard to detect even with your hand on the mast base.

That is par for the course with this issue/sound. It is really amazing how such a little gap can result in such a load noise – but as you can imagine, the loads involved are non-trivial. My solution which banished the sound for years (never came back) was to get a decent set of large calipers to measure the gap very accurately, and then added a couple of layers of epoxy (3 as I recall) to 4 inches of the inside bottom of the mast to eliminate the gap – but I know others have tried other solutions to this problem.

The others are correct, the sound comes from the base of the mast shifting ever so slightly at its base. This happened on our boat, Corroboree, (my custom design, not a Freedom) plus on another non-Freedom boat I know of. While the noise is happening, look closely at the base of the mast–you’ll probably see it move at its base in concert with the noise. Although the movement of the mast is slight, its mass is so high that the energy invoved in its shifting is considerable, and that adds to the volume of the noise. Also, the inside of the mast acts as an echo chamber which makes you think the noise is coming from far above deck when in fact its source is near your feet!

The solution as stated by Jamesorr works. Good luck.

Eric

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Thanks guys! You just never know, i thought a sheave box or sth ripped itself out and is hangin on a line that comes out at the base. When i ha ve someone else steering (flying solo currently) ill go look at the base of a mast to see if there is movement. Ballpeen hammer sounded about right! Serious noise. How can anyone sleep in the v berth ill never know. First i thought the noise is below deck, and i felt the bangs when i out my hands on the mast, the i thought its about 5 feet abive deck…and its probably lower than that.
Thanks for the answers! Now i go watch the transmission get ripped out to be rebuilt.
Caribbean fun.
Cheers y’all.

Tighten down the bolts on the mast plate as much as possible. If that doesn’t stop the problem, then the mast most likely doesn’t fit snugly on the mast plate. To solve this, I pulled the mast and had the inside coated with a release agent. We then placed a layer or 2 of fiberglass cloth on the mast plate, and slide that into the mast to get a tight fit. :grinning:

I’ve replaced or repaired all the main components of the mast system on my M28 - repaired the base (“top hat”), added a layer of glass/epoxy to the interior of the mast, replaced the deck ring with the studs with a new SS fabrication (the original aluminum one had crumbled to pieces), and replaced the polyurethane ring or “wedge”. All of it’s posted here on the site, and it did fix all the problems I had with the banging.
In order to get a good fit between the mast and the base when I added glass to the mast interior, I made molds of each. I still have them and would be happy to loan them to any other Freedom owners if they would be of help (again they are for a M28).

Is the mast alloy or carbon?