I have a Hunter 33 with a Kenyon spar. At the masthead there are 4 aluminum sheaves. They are very corroded (on surface) but not cracked. The bearings seem ok. Can I clean up the sheaves and paint them (to help preserve) or should I replace them? They cost about $80 each (RigRight, shipped) and I don't want to spend the money if I don't have to. If I can clean them up, any ideas on what to use to clean aluminum? Thanks!
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If it ain't broke...
As long as the sheaves roll freely and there are no snags or sharp edges that would damage your halyards, don't fret over them. Any coating you put on them would wear off anyway. Also, they're not exposed and visible from the deck.
As long as the sheaves roll freely and there are no snags or sharp edges that would damage your halyards, don't fret over them. Any coating you put on them would wear off anyway. Also, they're not exposed and visible from the deck.
Kenyon masthead sheaves
Mike, when I refitted the mast on my 79 H33, the sheaves were pretty much corroded with the typical white aluminum oxide. AFter taking them all off, (with the mast horizontal), I just wirebrushed them up good, cleaned the bearing surface of the impregnated bronze bearing and the mating sheave surface, painted the sheave and put it baack together. The sheaves are solid aluminum stock, the bearings good for the service intended and I'm sure will outlast the boat. The big thing is that the sheave runs free. Good opportunity to rework the masthead and spreader fitting and all the shroud tangs and bolts too.
Mike, when I refitted the mast on my 79 H33, the sheaves were pretty much corroded with the typical white aluminum oxide. AFter taking them all off, (with the mast horizontal), I just wirebrushed them up good, cleaned the bearing surface of the impregnated bronze bearing and the mating sheave surface, painted the sheave and put it baack together. The sheaves are solid aluminum stock, the bearings good for the service intended and I'm sure will outlast the boat. The big thing is that the sheave runs free. Good opportunity to rework the masthead and spreader fitting and all the shroud tangs and bolts too.
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Clean and reuse
I'm with the other guys Terry. Just clean them up. I just rebuilt my masthead and was pretty meticulous to replace any worn parts. I had to have some axles made. One apparently took some lightening and a lower was mashed in removal...sheaves themselves fared well. Almost 25 years old. Would sure be nice to find some teflon coated stock to make new axles out of! Maybe sometime in the next few years before I re-work it again. IslandJack
I'm with the other guys Terry. Just clean them up. I just rebuilt my masthead and was pretty meticulous to replace any worn parts. I had to have some axles made. One apparently took some lightening and a lower was mashed in removal...sheaves themselves fared well. Almost 25 years old. Would sure be nice to find some teflon coated stock to make new axles out of! Maybe sometime in the next few years before I re-work it again. IslandJack
Axles?
For the H33 Kenyon masthead, the bronze bushing acts as axle and bearing. The oil impregnated bronze bushing is slightly wider than the width of the sheave and when the through bolt is tightened, is clamped in place, guaranteeing that the bearing surfaces are the outer surface of the bushing and the hole in the sheave, not the through bolt and the inner surface of the bushing.
For the H33 Kenyon masthead, the bronze bushing acts as axle and bearing. The oil impregnated bronze bushing is slightly wider than the width of the sheave and when the through bolt is tightened, is clamped in place, guaranteeing that the bearing surfaces are the outer surface of the bushing and the hole in the sheave, not the through bolt and the inner surface of the bushing.
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Possible source
I rebuit my Kenyon boom an few years back and was able to get some parts directly from Kenyon, Inc. which is (was)now a subdivision of Sparcraft (Isomat), Inc., 1031 Amble Drive, Charlotte, NC 28206: The number was 704-596-9449 Ext. 308 and it may still be good. Ask for Rusty Privette if he is still there. They have some stock of replacement parts for the mast and boom.
I rebuit my Kenyon boom an few years back and was able to get some parts directly from Kenyon, Inc. which is (was)now a subdivision of Sparcraft (Isomat), Inc., 1031 Amble Drive, Charlotte, NC 28206: The number was 704-596-9449 Ext. 308 and it may still be good. Ask for Rusty Privette if he is still there. They have some stock of replacement parts for the mast and boom.
Most interesting ....
My sheaves are the same aluminum, but the bushings are phenolic (plastic), fixed in the sheave, and turn on (if I recall) 1/2" "axles" at the masthead, and more specialized fittings with the same size shafting in the sheave box at the base. The axle shafts are simply stainless stock. I just clean them up and lubricate, most recently a red synthetic grease that seems to be working, although nothing seems to last too long in that application. If you really have a deep seated need to replace them talk to the folks at Garhauer marine. They told me they will make up ball bearing sheaves for not too much money. Their stuff is always a good value.
My sheaves are the same aluminum, but the bushings are phenolic (plastic), fixed in the sheave, and turn on (if I recall) 1/2" "axles" at the masthead, and more specialized fittings with the same size shafting in the sheave box at the base. The axle shafts are simply stainless stock. I just clean them up and lubricate, most recently a red synthetic grease that seems to be working, although nothing seems to last too long in that application. If you really have a deep seated need to replace them talk to the folks at Garhauer marine. They told me they will make up ball bearing sheaves for not too much money. Their stuff is always a good value.
maybe semantics
Terry, I'd call the bronze bushing in the pic a bushing for the sheave, and the stainless pin or bolt going through it the 'axle'. Does that bronze press into the sheave? I never pushed any out of my sheaves and was wondering what they looked like before installation. Jack
Terry, I'd call the bronze bushing in the pic a bushing for the sheave, and the stainless pin or bolt going through it the 'axle'. Does that bronze press into the sheave? I never pushed any out of my sheaves and was wondering what they looked like before installation. Jack
semantics? maybe year model
Sam's descriptions of the sheave construction for his 83? H33 which is quite different from what I found on my 79 H33 indicates that even in a single boat design, a long production run may show significant differences from first to last. When I first took the masthead sheave assembly apart on my boat, I interpreted it as Island Jack indicates with the bronze as a bushing, and the through bolt as axle. I cleaned the whole thing up and since the bushing was a sliding fit in the sheave, tried to make it rigid with 5200. Wasn't till I tried to reassemble the masthead that I realized that tightening down the sheave assembly bolts clamped the bronze bearing (bushing) tight preventing the sheave from turning and so if finally dawned on me that at least for the 79 H33, the bearing surface was between the outer surface of the bronze bearing and the sheave and so had to clean all of that 5200 off. I used some heat to remove the 5200 stuck bronze bearings and that's when I found that the bronze was impregnated with oil. Below is a photo of the masthead fitting. It may well be different from later production boats also.
Sam's descriptions of the sheave construction for his 83? H33 which is quite different from what I found on my 79 H33 indicates that even in a single boat design, a long production run may show significant differences from first to last. When I first took the masthead sheave assembly apart on my boat, I interpreted it as Island Jack indicates with the bronze as a bushing, and the through bolt as axle. I cleaned the whole thing up and since the bushing was a sliding fit in the sheave, tried to make it rigid with 5200. Wasn't till I tried to reassemble the masthead that I realized that tightening down the sheave assembly bolts clamped the bronze bearing (bushing) tight preventing the sheave from turning and so if finally dawned on me that at least for the 79 H33, the bearing surface was between the outer surface of the bronze bearing and the sheave and so had to clean all of that 5200 off. I used some heat to remove the 5200 stuck bronze bearings and that's when I found that the bronze was impregnated with oil. Below is a photo of the masthead fitting. It may well be different from later production boats also.
My plan..
Thanks to all for your advice. I am going to clean up the sheaves and axles. I found the bolts that hold the masthead in place are slightly bent and one has been eaten halfway through by the wire halyard. Mike
Thanks to all for your advice. I am going to clean up the sheaves and axles. I found the bolts that hold the masthead in place are slightly bent and one has been eaten halfway through by the wire halyard. Mike
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