new mast base cap won't fit!

[tag]

I just picked up the mast base cap and the mast top cap with the fairlead (my current top of mast has a domed cap, but a small thru-bolt with a small block for the halyard -- see picture below. I currently don't have any base cap at the bottom - about 6 or 8 inches up the inside of the mast I can see some wood blocking - I assume the cork?).

I opened up the packaging for the mast base cap to test fit it - and the base cap outside diameter is too large. Has the mast inside diameter been changed? My boat is pre-71, not sure if the mast is original, but it seems to be. I haven't checked the mast top cap yet, but I would assume I'll run into the same problem there.

Any thoughts other than trying to carefully trim down the plastic or heavily sand down the plastic base cap to get it to fit?

thanks.

 

[Wayne]

Any thoughts other than trying to carefully trim down the plastic or heavily sand down the plastic base cap to get it to fit?

Do the new caps have these ribs? The ribs may be all that needs sanding down for your year mast.

As an aside, the gap created by these stand-offs between cap and spar wall would certainly explain the leak issues people have been experiencing with newer masts and spars.

 

[tag]

Wayne,
I haven't checked the mast top cap yet, only the base cap.
The new base cap does not have any ribs.

tag

 

[Webfoot]

The mast cap I bought had ribs. I used a wooded block to pound it in since it was such a tight fit. Tight enough that I did not need to use any sealer. It is a trick to get it started going in straight, a little crooked and it will jam up going in.

 

[Porpoise2]

"...Any thoughts other than trying to carefully trim down the plastic or heavily sand down the plastic base cap to get it to fit...?"

The mast could be burred or "rolled" (when last cut) to make it appear smaller.

Try coarse sandpaper on the inside to remove any excess.

 

[67stang]

I had the same problem. I bought the Sunfish cap and bottom for my Phantom mast and they had to be ground down to fit. The mast for my 64 sunfish was identicle in all measurements to the Phantom ( the only difference is different colors).
I used a file ( needed a bit of material removed) and when it fit tight, I used marine caulk on both top and bottom, and re-riveted them (Phantoms used rivets).

 

[JSDouglas]

Absolutely have been there. Was told here that the newer masts have a larger inside diameter that your new cap was made to fit on. You'll have to sand it down. Unless you have a lathe, there really isn't any easy or good way to go about this - just start sanding with around an 80 grit. When you get a really snug fit - keep sanding. You're looking for a really easy fit (but not loose) and finish it off with marine caulk. Have fun.

 

[tag]

Okay, I figured as much. I will try to sand it down this weekend.
It does appear as if the very end of the mast at the base is slightly tapered.

 

[derekcjackson]

I know there can be some variance in the tubing based on the molds they came from. Even from the same mold, over time there is a build up of some kind of residue that leads to change. The Laser Forum has a ton of discussion on this and is one contributing factor to the variance in their spar stiffness across the different manufacturing plants.

At one point a few years back, I came upon an older Sunfish mast with a pulley like in the picture. The top had a plastic cap as shown in the picture. However, the bottom of the mast had a bronze or other hard metal slug in it. It definitely did not look like a one off replacement for a plastic cap that a prior owner had put on. The mast was the same basic dimensions and appeared to be a Sunfish mast.

The mast had taken on water, so I decided to remove both end caps and the cork inside to clean it out. This turned out to be a huge mistake. I basically had to destroy the slug to get it out. Unfortunately, when I tried to replace it, as described here, the new plastic cap did not fit inside it. Just like everyone else, I had to shave it down a little and forced the plastic cap on.

 

[mike4947]

As was posted the new Sunfish masts are a larger inside diameter (thinner wall) so that both Lasers and Sunfish use the same tubing.
As an historical note the original sunfish masts were swaged so they were tapered from top to bottom. Those were the earliest aluminum masts. Folks thought that the taper made the mast lighter but it was the same weight just "smooshed down" to a smaller diameter.