BUTTERFLY REPAIR - SHEAVE REPLACEMENT

by Pam

Lowes part #349199

At the top of the Butterfly mast is a sheave.  This is the roller thingy that you use to pull up the main halyard.  When it works, life is good but when it starts to get brittle and crack, the halyard gets stuck at all the exact wrong times and it's a real pain.  Perhaps being in Texas this is more of a problem because we sail year round and we also have the Texas sun.  Over the years, spare masts laying around the club have been stripped of their sheaves because finding the precise replacement part is a challenge.  The Butterfly parts diagram at Torresen Marine indicates the replacement part is a "mast head with sheave" and there is no price listed.  Sounds expensive to have to replace the mast head just to get a little sheave.

Well, thankfully, I have a house that inspires me to spend countless hours at Home Depot and Lowes walking the isles looking for all sorts of repair parts.  And what do you know, I found a Butterfly sheave.  While on the docks with Bruce this weekend for race duty ... yes, that would be without signing a liability waiver and without permission from WRBC's esteemed board who have decided that Doug and I should be banned from the club for life because ... oh, sorry, got carried away.

So, anyway Bruce was repairing an old mast that was missing a sheave and all the spare sheaves had been pilfered so I shared my find with him and he researched the details: 

Lowes carries a clothesline pulley that is 2 1/2 inches in diameter and a 1/2 inch wide.  This is identical to the Butterfly sheave and only costs $2.38 (Lowes' stock number 349199).  In order to put it in Bruce had to drill out the rivets on one side of the mast head fixture (but not both).  One side will slide out and then the sheave can be put in.  The 2 halves of the mast head are not attached together.  Presto, a smooth running halyard and a super affordable repair.  Thanks Bruce!!