Mast pumping

[George Warren]

Last year I bought A 1975 30ft hunter.after replacement of core in cabin to and replacement of interior, I launched the boat. I only use the boat in the fall and winter. Still using now. My concern is when it get rough and windy the mast pumps thru the cabin. I noticed this when i was under sail between Boothbay and Portland. I went down to warm up and noticed the mast moving up and down with each wave. I masured this at about 1/2 to 3/4 of an inch. This is the first thru deck mast i have owned. My thoughts to correcting this is to put a collar arount the mast that ties it to the cabin top. Has anyone ever noiced this and if this is something i should be concerned of. The step is in good shape and rigging is not overly tight.

 

[John Drost Jr.]

IS IT THE MAST

IS THE MAST MOVING OR IS IT THE TOP OF THE CABIN MOVING UP AND DOWN AS THE HULL FLEXES, JUST A THOUGHT, JOHN.

 

[Tom M.]

Taming of the mast

You say that this is a keel mounted mast??, if this is true, Your mast should NOT pump, I most cases, a deck steped mast will normally pump, the questions You must ask yourself is: is my standing rigging have the proper tension ?, is my cabin top flexing, because my support post is not doing it's job, because of my revamping the interior, if all of the above are correct, then my deck steped mast is acting normally, to eliminate this pumping, You must add a inner forestay or intermediate shrouds, or both, the shrouds are easier to add on, than the inner forestay, which, requires a strong well secured fwd deck plate with the addition of a wire w/ a turnbuckle secured to the v berth base.