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  • #4503

    [attachment=1:1y8oovud]P1010900.JPG[/attachment:1y8oovud]
    [attachment=0:1y8oovud]P1010901.JPG[/attachment:1y8oovud]
    [attachment=2:1y8oovud]P1010899.JPG[/attachment:1y8oovud]

    Guys, pictures of my seized foresail sheave. Note also broken lug for forestay. Any suggestions for repair would be most welcome. Presently I am considering cutting the assembly out and replacing with something I can pop rivet in place. Would aluminium rivets be strong enough I wonder……

    cheers

    Tony

    #11099
    Dave Barker
    Keymaster

    Hi Tony,

    Sorry your Wayfarering hasn’t gone more smoothly!

    [attachment=0:39i6t25y]sheave.jpg[/attachment:39i6t25y]

    I’ve just taken the mast off our Mk2 (W6151), see photo. As you will see through the haze (scratched phone) our forestay is attached to the mast via a fitting which is riveted in place, so that obviously is a possibility. I think monel rivets or even stainless steel would be the way to go though, not aluminium.

    The sheave on ours fits into a slot cut in the mast, rather like the spinnaker sheet blocks people often use through the sidedecks towards the stern. On yours, if you remove the pin that holds the forestay eye (the pin with the ring), will the two steel plates and the sheave pull out as one component? It may be that the broken lug is nominally non-loadbearing.

    I’m a bit surprised to see a braided halyard (normally wire) and there’s quite a lot of wear around the slot as well as the sheave itself. Perhaps the mast has been wobbling around in a dinghy park with a very loose forestay at some time in the past? Could this even be linked to the bend in the mast and the foredeck damage?

    Anyone else got a mast with fittings like Tony’s?

    #11100

    Thanks Dave for taking the time to post that, the picture is exactly what I needed to see.

    If I can source a sheave and forestay fitting like yours I’m sure I could “make” them fit. Any ideas for a supllier?

    cheers

    Tony

    PS Mast bend not an issue as she sails well enough for me, and I’ve strengthened the foredeck with fibreglass, it aint pretty but does the job. The boat has clearly been abused, reflected in the price I paid for it. At least she floats and whizzes along nicely! Almost got to the Isle of Wight the other day…..

    #11101
    Dave Barker
    Keymaster

    I like your style. Maybe worth ringing Selden on (01329) 504000. Sheave box – I’m not sure of the correct part number – I think it may be 505-071-01 (or suffix -02 for ss bearing sheave), but check with them first, as this sheave takes quite a load. (They’re on the website at http://www.seldenmast.co.uk/fittings/listing.asp?Category_ID=3). About £20 plus a couple of self-tappers. File the opening to have nice curved ends (rat-tail file) to avoid stress-tearing of the mast wall. It could be a good time to change the halyard too if you have any concerns about it.

    Forestay fitting – 508-476 or 508-477. (I like the look of 508-477 better – the other one looks flimsy, see http://www.seldenmast.co.uk/fittings/content.asp?Category_ID=4). Ask the supplier about rivets – the fitting may come with them included.

    #11102
    Colin Parkstone
    Participant

    Tony, I have sent you a PM, Colin

    #11109

    In case anyone stumbles upon this thread, here’s an update. The sheave assembly in question has been removed and shown below. I guess I have a snowball’s chance in hell of finding a replacement….

    [attachment=0:337ddtaz]tony boat 002.jpg[/attachment:337ddtaz]
    [attachment=1:337ddtaz]tony boat 001.jpg[/attachment:337ddtaz]

    Big thanks to Colin who put me on to how to remove it. The assembly was punched out (it wasn’t easy but it worked) from the aft of the mast, through the mainsail luff channel. As I’ve been told, the 2nd sheave must have been for a 2:1 reduction pulley system that would have originally been used to tension the jib halyard. The mast has clearly been modified.

    Looks like I’m back on the water, but am defo on the lookout for a 2nd hand mast now.
    cheers all and thanks for the help.

    Tony

    #11125

    A couple of years ago I tried to replace the “plastic” forestay sheave in my 1996 Proctor mast for one of alloy. Nothing in the Selden (ex Proctor) catologue seemed to be the correct dimensions. Phone calls to Selden led eventually to Ian Porter (no surprise) whose advice, as I remember it, was that some current Selden fittings are not exact replacements for those from Proctor masts.

    So creativity may be the only altenative to a new mast.

    #11126
    Swiebertje
    Participant

    That is not a pulley system!
    The old Proctor (not Seldén) masts used to be waterproof. Those masts had welded chambers to hold the sheaves. The halyards in those masts used to run through the luff channel together with the sail’s bolt rope. The big advantage of those masts was that they floated and thus helped to prevent inversion. Obviously you need one big sheave or two small ones, to span the distance from the front of the mast all the way through the mast to the bolt rope channel at the back of the mast. And that is what you see, two sheaves to guide the halyard from the front to the back.

    Those old masts are said to have better bending characteristics as well, and are most definitely worth saving!

    Maybe a welder could fix the protruding part on your mast? Aluminium is perfectly weldable though it needs specialised equipment and an experienced welder.
    The sheaves are riveted to the side plates. Rivets can be removed by drilling them out. Then find some good replacement sheaves of approximately the same size and two new rivets. Any metalworker should be able to get that job done in a jiffy but it is not out of reach of a DIY person either.
    If all else fails have your local smith make two Aluminium sheaves on his lathe. Aluminium sheaves are good enough IMHO. Though stainless steel would last longer, your current (Aluminium) sheaves have lasted for 40 to 50 years. Finally, I don’t see why modern hard wearing plastic sheaves can’t be used. I would probably choose aluminium rivets for they agree galvanically with the mast and (Aluminium) sheaves.

    I don’t think it would have to be an expensive job but it may take some time and effort to find the right materials and craftsmanship if you are not in the boating business.

    #11127
    Swiebertje
    Participant

    I looked at your sheave pictures again. Those sheaves don’t look bad at all.
    What I would do is take the burrs off with a small round file and rolled up sandpaper, grease them and see if they still work before trying to replace them. Its worth a try IMHO.

    If you don’t trust the stay attachment anymore you could add a separate stay mounting plate, just above the halyard sheave, as shown in Dave’s pictures. A dab of Sika would ensure your mast stays waterproof and floating, while a couple of Monel pop-rivets are surely strong enough to keep the stay attached to the mast for many years to come. Since halyard tension mainly presses the sheaves down in to the mast the damaged attachment point is not critical provided the stay is moved to an alternative attachment point.

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