J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment mast foot

Hi,

I'm a new J30 owner in Québec City, Canada. (sorry, I speak english very bad ! )

My question is about mast foot.

When we put the mast on, we notice that the hole for the mast on the deck is bigger than the mast circumference. What do you put to fill this gap and how do you weatherproof the mast foot ?

We put some little blocs, then wrap with tape, but it seems not very good to me. I would like to know how other J30 do it...

If you have some picture of your mast foot, it will be very helpful for us ! Thanks !

Marie

Marie,

There are typically wooden shims or a urethane compound such as "Spartite" poured to keep the mast in position. It is important to have the mast in the proper position. The position is best set with the shrouds and stays loose. The mast step should be located 1" back from the molded lip on the step in the vberth. The mast should be centered in column over the keel. A good trick is to use a sight line hanging from a step ladder about 60 feet behind the boat while on the hard so you can use it as a reference to see from the bottom of the keel to the top of the mast. I used lines tied around the mast and turning blocks to the winches to properly center the mast. The front of the mast should be positioned 11.5 feet from the stem of the bow, also using lines and a turning block to winches so the mast can be pulled forward. Note that the mast may not be centered in the hole when it is properly aligned to the keel.

Once the mast is centered and positioned fore/aft correctly, use wooden wedges to fix the mast position at the deck. An alternative is to create a mast collar using a urethane such as "Spartite". See my Rhapsody post that also contains a link to my blog where the Spartite process is described.

After the mast is positioned properly, you can put on a mast boot. There are some sold that are one piece and slide on the mast before the mast is inserted in the hole. Rigrite sells a mast boot on this page. Others have taped on rubber seals and used canvass or Sunbrella covers.

On Rhapsody I use Spartite and the Rigrite mast boot that was split in the aft seem and taped to allow easy removal. The Spartite helps keep the mast centered, and helps keep rain from dripping down the mast.

On early J/30s, the hole for the mast in the deck is very large... much bigger than later models. They used wooden partners to position the mast, and reduce the leaking.

Later models have a plastic(?) mast boot around the mast that fits pretty snugly over the hole. If that is no longer on your mast, SparTite would be a reasonable substitute.

What is your hull number?

Marie has "NEMO" hull 283

Hull number is 283.

I think it is one of the earlier models because the hole is very large.

The former owner give us some little blocs to put around the mast, in order to fill the gap. But it seems strange to me, because theses little hard blocs are making hard pressure at the contacts points. Moreover, the deck mast foot seems already stressed, there is little cracks. I think that the pressure from the blocks will worsen the cracks.
A picture is better than words :


Then we wrap it in a special mast foot tape in order to waterproof the mast foot, but it is not perfect, there is water leak while raining.

So, I am looking for a better system.
I will look at spartite and other mast boot. We want something that can be remove easily because we will probably dismast next fall to change pulleys in mast head (there are old pulley for cable halyard but the current halyard are ropes, not cable, so there is a lot of rubbing).

(Please correct me if I use bad words, because I am not familiar with english marine vocabulary !!)

Also see thread beginning at
Mast Step Position

That's the standard size hole not the big one. Mast boot tape will do the job. But jib sheets tend to break it down. So I taped it, than covered it with something like this: A practical mast boot. Instead of truck tire inner tube I used a piece of sunbrella fabric.

A 7 MB PDF version with a better view of the above on page 56 here.

Hello,

Thanks for answers !

About Spartite :
Do you pour the Spartite when the rigging is tighten or loose ?
I understand that you pour it when the rigging is loose. But isn't it better to pour it when it is loose ? Because the Spartite will solidify and then, when you will tighten the rigging, there will be compression on the Spartite collar ?

Can you easily dismast and restep the mast with this Spartite ?
Do the Spartite collar stay on the deck hole or stay on the mast when you dismast ?

Thanks !!

Here is the Spartite website link that contains a FAQ section. Spartite is poured with the rigging loose, but the rig positioned by lines tied around the mast and winched to make sure it is centered and proper fore-aft location. The backstay should be on tight when Spartite is poured.

You line the hole with Vaseline on the mast and deck so the Spartite "donut" will slide when you pull the mast. It usually stays with the mast.