Mastbase Maintenance
Related links: New
Mastbases, Used Mast
bases, Mast base Hardware
The Mast
base is the heart of a sailboard. Failure of a
mastbase is one of the worst things that can happen to a sailor on
the water, especially if your board gets away from you! Here
are some basics help you maintain your mast base. On this
page, we will cover what to look for in a base to see if it needs
attention. Also, we will cover how to fix a mast base.
On any mast base repair where the bolt in the joint is loosened, it
is critical that RED permanent lock-tite is used.
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| Signs of trouble on a mast base:
If any of these signs show, it is a good indication that
repairs should be done. |
| Worn Boge
Joint: Any signs of cracking on a boge joint is a sign
that it needs replacing. |
Waiting for pictures |
| Worn cup:
If there is excessive lateral movement in the swivel joint
on either side of the boge joint, the cup is probably warn,
and needs to be replaced. |
Waiting for pictures |
| Too much play in bolt fittings: The fittings on
either end of a boge joint should turn, but shouldn't
wobble. If it wobbles, the bolt needs to be removed, re-locktited
(RED locktite), and re-tightened. |
Waiting for pictures |
| Worn or missing safety
webbing: Every universal joint on a sailboard
should have a safety webbing. If the joint fails, the
safety webbing should keep it together long enough for the
sailor to return to shore. |
Waiting for pictures |
| |
Waiting for pictures |
| There are basically three common
types of universal joints used in mast bases: The rubber
U-joint, also called a "boge" or a power joint; a
tendon joint (also called a Streamlined joint), and a
mechanical joint. |
| Boge
joint : This popular joint has female 8mm threads on each
end. Windance sells joints made by Chinook
and W-Hawaii. |
Tendon
joint : This stiff joint has bolts coming out of the
joint, so it is a bit different to replace the joint. Popular
in California, the tendon is durable. The tendon
part can be easily replaced without replacing the whole joint.
At Windance, we sell the Complete
joint or just
the tendon. |
Mechanical
joint: This joint has 8mm female threads in each end. |
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The most common type of repair that we do here at Windance is
replacing the boge joint. Disassembly of the mast base is the
most difficult part. Permanent Locktite is used to lock the
bolt into the threads at the correct tension. Because of this,
removal of the bolt can be difficult. Clamp a piece of webbing
into a fixed vise. Roll the boge joint up in the webbing so
that the webbing clamps down on the boge joint (without damaging
it). If the boge is shot, you can just squeeze it in the vise.
Using a 13mm socket wrench, remove the bolt from inside the
cup. Repeat the procedure for the other end. This end
can prove more challenging, as the fittings can be
smaller. Once you get the joint dis-assembled, you
should clean out the inside of the threads on the joint with a 8mm
tap. After examining all the parts, replace worn ones, and
re-assemble. Keep these important comments in mind when
re-assembling a mast base.
- Always use permanent locktite (or equivalent) when assembling
a mast base.
- Always use a metal washer under the head of the hex bolt or
nut that goes inside the cup.
- Especially on hot days (as the locktite can cure too fast), do
a test dry run before applying locktite. This makes it
easier to make sure it will assemble properly.
- When using locktite, be sure to get it all the way around the
rim of the threads, not at the bottom of the hole.
- Let locktite cure fully before taking mast base out on the
water. Heat helps it cure, so you can put it on your
dashboard in the sun to help it cure.
- Cup end of the boge should be tight enough to be able to hand
turn, but not wobble.
- If you are using a Chinook two
bolt mast base plate, the bottom bolt needs to be tightened
as tightly as you can. The rotation below the boge joint
occurs between the two parts of the two bolt plate and the pin,
not between the pin and the boge.
- If you are using the one bolt Chinook, or Windsurfing Hawaii
plate, it is important to have the bolt below the boge as tight
as the one above the boge: able to twist, but not wobble.
Click here to see a diagram of how many mast bases go together.
Mast base trivia:
The first "universal joint" used on a sailboard was
made of rope. Newman Darby, when inventing the sailboard used
a piece of rope to allow the rig to be a freely movable in all
directions.
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