2006 mast plug

LAuman

Member
Ref. “What’s with fattening the mast” thread 2/25 -3/25/06.
We just got a new 2006 ‘fish yesterday and the mast has two 1/16”+ pins, 3/16” and 1 5/32” above the base of the Al tubing. Presumably, the upper one fastens the new reinforcing insert. I’m glad they’re using the pins instead of “pop” rivets, but I’m still concerned with the fact that there’s only one fastener through the bottom plug. We have a 2003 and a 2005, both of the masts for which had single rivets. . . and they both tore out messily.
It also appears to me that the mast plug has no sealant, and thus will probably leak water into the mast. The pins are tiny, and I hesitate to try drilling one out to put sealant around the plug. On the other hand, if I don’t add another pin or two, it might tear out anyway!
Has anyone had experience with this?
 
The caps are held in by a groove pin or roll pin seemingly as an extra measure. On all we’ve pulled those caps have been pretty tight and pins seem unnecessary. We don’t know what would cause the cap to tear out in normal use. You could add extra pins Sunfish sells them 79513 is the number on a package we have.

The pins are hardened steel so drilling on them would most likely just bugger up the mast. The way to remove the pin is to use a tiny pin punch and press the pin to the inside. If you don’t push too far the pin stays in the cap and is easy to pluck out when the cap is pulled.

We’ve never seen a builder sealed cap. Cork or a foam plug shoved inside the mast ends seems to be the norm. On Hobie Cats the mast plugs are polyfoam sealed by silicone. Sealing the caps doesn’t matter. You could do that too if you see the inner plugs aren’t sealed.

To seal the mast if you don’t pull the caps smear a film of sealant around the mast at the cap lip. If you pull the cap and seal the insert part you’ll never get the cap off in the future without cutting it into pieces. Seal all the fitting too. Pull cleats and smear a film of sealant on the cleat base. Put sealant on screws or rivets when reinstalling. Plug rivet centers and hollow roll pins with a squeeze of sealant.

This mast insert thing sounds weird. From reading the comments it looks like Vanguard lightened up on the aluminum. We don’t see a new part number for late model mast caps that might indicate an ID change. Sounds like the shift was metallurgic. Has anyone been keeping statistics on breakage? Is it really happening more frequently in standard use? If the numbers prove a problem sounds like Vanguard’s responsibility and they owe some newer Sunfish owners.
 
Here's where I'll throw in my 2 cents. My Sunfish are old, so I've never dealt with the newer mast type problems. Sailing only in salt water, over the years, the end of the mast becomes quite corroded. I've solved this problem by driving out the pin(s), and removing the end cap. Next I take a large tubing cutter and remove about one eighth of an inch of tubing, eliminating the bad material (aluminum). A new end cap completes the job.
 
Got a vey nice note from Vanguard on this subject:
"I questioned one of the engineers and this was his response...

The current SF masts do differ from older masts.

We removed the cork years ago. It rotted out, tended to come loose, and
didn't really do anything. Flotation wasn't an issue. So, current masts
have no cork.

The masts are sealed at each end with the caps and silicone.

Current SF masts have an inner sleeve. The sleeve is held in place with a
tapered drive pin.

Each end cap is also held in place with a tapered drive pin. The pins
provide a cleaner mast. The require a much smaller hole so there's less
stress concentration created in the mast from drilling larger holes. They
are a press fit, tapered, and are solid so they also seal better than the
rivets.

By design they are not meant to come out. We didn't want people opening up
the masts and shifting the location of the inner sleeve. There's no cork in
the mast to come loose so there should be no reason to open them up. If it
is required, the pins are tapered. They can either be drilled out or
pressed through to the inside using a punch. The existing hole can then be
enlarged to accept a rivet or larger drive pin, or the old hole can be
sealed and a new hole created."
So, . . Thanks, Vanguard. I'm not doing anything to the new mast.
 
LAuman,

Wow, everyone usually just flogs the horse with lashes of homeopathic conjecture .

What a concept, going to the source.

Kudos to you.
 

Back
Top