Replacing sheaves on Schaefer blocks

[Ben Green]

I have about six Shaefer blocks on my '71 Typhoon that need new Delrin sheaves, and I wonder if anyone has done this job themselves? The replacement sheaves are cheap (less than $3)and available from JSI/Sailnet and other stores, and the rigging guy at JSI, who is replacing my standing rigging, said if you have a drill press you can drill out the old rivet and replace it with a clevis pin. Has anyone ever done this? Any suggestions on how to get the old rivet out without tearing up the block? Thanks,
Ben Green




bcgreen@mailer.fsu.edu

[Bristol Bronze]

I have about six Shaefer blocks on my '71 Typhoon that need new Delrin sheaves, and I wonder if anyone has done this job themselves? The replacement sheaves are cheap (less than $3)and available from JSI/Sailnet and other stores, and the rigging guy at JSI, who is replacing my standing rigging, said if you have a drill press you can drill out the old rivet and replace it with a clevis pin. Has anyone ever done this? Any suggestions on how to get the old rivet out without tearing up the block? Thanks,
Ben Green

Dear Ben,

Drilling out the rivet and replacing the sheaves in your blocks is no problem. Mark the center of the rivet with a felt tip pen, hit the spot with a center punch and then use a drill press to drill out the rivet. Since the rivet is probably stainless steel you will need to use a sharp drill, probably a new drill bit will work best as they come nice and sharp from the factory.

I strongly suggest that you use some other material than Delrin for your new sheaves. Delrin is polimarized formalhyde. Its chief advantage is that it is inexpensive. Delrin will distort under load and it is subject to deterioration by sun light. I recommend that you pay a little more and buy either metal sheaves or sheaves from a better plastic such as Torlon.

I frequently replace the sheaves in modern blocks for my friends. I have used my standard Bronze sheaves with very good results. I worked on some blocks last Spring that were made in 1892. The Bronze sheaves were still fine.

Roger W.
Bristol Bronze
401-625-5224



rogerw@bristolbronze.com

[Jeffrey Clark]

My '79 needed the same last spring. Drilling out the rivets is easy enough but the shaft for the sheave is shouldered and I came to believe the end result of my drilling, grinding and peening was not going to be pretty. I checked with Shaefer and found they would do the job for about $20 per block which is about half the cost of new blocks. In the end I had them do the job and was satisfied with the results. Now is a good time to do it, they get pretty busy by early spring.

Good Luck

Jeffrey Clark



jclark@weemva.com