Latest News: Forums Technical Newbie Q’s. Mast Foot and Mast Pin help!

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  • #4461

    Hi everyone I am the proud new ownwer of a Mk1 composite Wayfarer. Look forward to chatting to many of you.
    My boat is on Alton water in suffolk and I have been out several times now. However I have some queries. Particularly because after myfirst outing I found I was not 100% confident in the boat which was compounded by the gusty conditions.

    Ok first of all!

    (See pic)The weight of the mast seems to be sitting on the mast pin. As a result themast pin has bent slightly. As a result the the foot of the mast doesnt seem to sit on the track..there seems to be a couple mil’ gap underneath.

    My fear is that something will break leading to calamity! My friend suggested the perhaps the pin didnt need to be there? Is this right? If so is this the best temporary solution in order to get me back on the water until a proper fix can be made?

    I have have also noticed that the bolt on the bottom track that stops the foot of the mast from pivoting or sliding aft has delflected or bent slightly. I am concerned that this to may give way. How much force is pushing the base of the mast aft? Is this force hugely increased as a reult of the foot not being seated, but being pivoted around the mast pin?

    Also I think at some stage I must remove all of the the foot of the mast…the thing with the pulleys or wheels on. The wheels have seized and as a result dont like it when I ‘highfield lever’ the wire halyard over their surface. It looks like they may split. Not sure what material they are made of. It doesnot look like plastic…rather something like incredible hard MDF?? How big a job is it to replace this? What is the foot of the mast bit called? i.e. the thing with the pulleys or wheels on.

    Finally could anyone help me with the tension on the shrouds? They seem a little loose, infact we slackened them off a bit the first sail we had (on the advice of my friend..by no means a wayfarer expert but a very good dinghy sailor)

    I am only pottering around at the moment trying to gain confidence. I would like a set up that is safe. I would like 100% confidence in the boat and the rig, but this issue with the mast not seated correctly has knocked me.

    Many thanks….may I add that I am now officially living the dream. I have a boat that I love, and a world and way of life that seemed so far off in the past has been opened up for me and more importantly my children!! (I hope that doesnt sound too pukey…but it is true!)

    Tim

    #10921
    bigal
    Member

    1. A new heel plug could well solve all the problems at the foot of the mast plus a new bolt at the back of the track . As long as the plug right at the bottom of the mast sits on the bottom of the track you should be OK . When you take the mast pin out does the mast drop ?

    2. As to rig tension the P&B tuning notes say that the leeward shroud should be just less than tight when going to windward .
    Depending on the strength of the wind this will require a rig tension of between 300 and 400 lbs .

    #10922
    Swiebertje
    Participant

    It is not unusual to have packing pieces between the hull and the mast rail. I prefer Delrin that I cut from one of those cheap kitchens cutting boards. The holes in the mast and in the tabernacle should line up. More details here.

    Before you do that check if the hull did not sink in. Some older boats do not have enough strength to support the mast whit the full rig tension on. If the GRP below the mast is dented or cracked in any way you should consider adding a wooden support inside the forward tank. There are some good essays on the Danish site that will help. Go here: Cracks in mast seat 1. Cracks in mast seat 2. (I use Google-translate to translate those web pages to English)

    Finally, exchange your the Aluminium pin for a 6 mm stainless one. A 6 mm pin (minimum size allowed while racing) allows a bit more play while trimming. Alternatively use a 6 mm galvanised steel bolt and wing nut and replace when it starts to rust. I bet you can replace it six times for the price of one SS mast pin.

    #10925
    Dave Barker
    Keymaster

    It’s a pretty straightforward job to replace the mast foot plug, and this would give you a nice free-moving set of sheaves. Remember that the bolt apparently restraining the foot of the mast isn’t the only thing stopping the mast from toppling forward, so don’t be spooked by the idea that it’s become bent. That can be replaced, then once it’s in what you are sure is the right position, it will last years.

    The key thing to remember is that the mast pin doesn’t do anything while the mast is up – it just sits there. It shouldn’t take any strain at all, either when the rig is tensioned or not, provided the mast is upright. A narrow (6mm) pin gives you a better chance of achieving this, but you may well need to tweak the mast step height with packers as has been suggested.

    Sort out the plug first, then set up the mast and perhaps even remove the pin, check the mast rake with a long tape measure (follow one of the standard tuning guides). Adjust the position of the new little bolt in the back of the mast step track and see if the holes in the tabernacle line up with the mast hole, with and without full rig tension. (You don’t want the pin to snag or stress the mast in either situation). If the height is wrong you can pack the mast upwards (if that’s the direction it needs to be moved!)

    For fore and aft adjustment, with full rig tension the mast is being pushed down really firmly onto the mast step, but a small amount of repositioning is possible. If the holes now line up through both the mast and the tabernacle you have a provisional position for the little bolt in the mast step track. Check that the holes still line up (with mast pin free) without rig tension.

    You may have to go through the whole tuning/tweaking cycle a couple of times, but once you’re satisfied with it you will feel confident in yourself and your boat!

    #10927
    bigal
    Member

    The bolt at the back of the mast step can only be moved in discrete distances so one has to deface the Queen’s currency by filing of the edges of a few 5p pieces to plug any remaining small gap .

    #10929
    Swiebertje
    Participant

    A complete mast foot is an expensive part. You may want to try to salvage the current one first. Give it a good rinse with kerosene or diesel oil and a paint brush. Or better, take it apart before cleaning. If the sheaves are damaged as you wrote, sheaves are available as separate parts through your local chandler. Except for the Spinnaker halyard, the sheaves are only used before we go out, while hoisting the sails. I wouldn’t worry about small damages but I would save the best sheave for the spinnaker halyard.

    The old sheaves were made from Bronze the modern ones are made from carbon fibre and epoxy AFAIK. Both types are still available from Seldén/Proctor through your local chandler.

    #10933
    PeterW3035
    Member

    It would also be a good idea to check the fibreglass end of the centre board casing that the mast sits on.

    On Bramble the end had been deflected down due to rig tension, rot in the softwood core and in adequate fixings into the timber sides of the mast step. I strengthened the whole of the centre board case and glued some solid timber struts beneath the fibreglass end of the centre board casing to give a solid connection between the mast foot and the hull.

    I will try and post some photos if that will help.

    #10936

    Thank you for those excellent replies.

    Ok if I understand correctly

    The mast pin doesnt actually do anything ‘structurally’- it is there for alignment. The fact that mine is effectively supporting the weight of the mast is wrong. Bigal..youre correct, when I remove the pin the mast drops 5mm or so allowing the plug to settle on the track!

    However this may be a result of a drop in the hull structure beneath the mast track. This could be why there are signs of wear as the mast plug has sat snug against the bottom securing trak bolt some time in the past. It could have been however that the previous owner sailed without the mast pin in. What would be most likely?

    To remedy I think I will

    Take down mast. Examine structure for obvious ‘drop’ in the structure beneath the track and around the front of the centerbaord casing. (How easy is this to diagnose?..Will it be obvious? Would it be ruinous to ignore for a little while so I can enjoy some sailing?). Bramble.. I will check to see if I need to do any work strengthening the centry board casing area. If it looks as if it is damaged maybe I will take up on your offer of some pics as I am certain they would be most helpful

    Remove mast plug, take apart clean renew bits and replace.. I will follow Swiebertje advice as I cannot afford to replace as yet!

    With the mast down, having already measured for the required packing, remove the track and refix with delrin packing ( builders window packers any good?)
    Swiebertje I read your other post and that is most informative. I can fix properly with some 5 x 60 stainless wood screws.

    I then can allow for fore and aft adjustment to align the holes in the tabernacle with those in the mast.
    thanks Dave Barker..can you pointme in the right direction for any of those tuning guides? I havent the foggiest about mast rake or tension, but will certainly be looking it up.
    Many thanks Tim

    #10937
    Dave Barker
    Keymaster

    Hi,

    Just to clarify about the mast pin – it’s just to assist with raising and lowering the mast (before & after towing or during bridge shooting), [edit] unless you race, which I almost never do, as reflected in the fact that neither Cockle nor Shearwater would measure as a legitimate Wayfarer.[/edit]

    This link http://www.yachtsandyachting.com/downloads/?s=73&ArticleNumber=17 takes you to one of the online tuning guides. Scroll down the page for a table of measurements, with some explanation too, but if in any doubt ask here.

    Looking at the photos it’s clear that there is too much gap between the pin hole in the tabernacle and the surface of the mast step (unless someone has sawn a bit off the mast, same effect).

    On Shearwater (Mk1 composite) there’s a chunk of timber under the grp moulding just beneath the mast step track. It extends quite a way towards the centreboard case, say 200mm.The timber is in turn supported by a vertical block between the sides of the tabernacle – this block is what takes the load to the hull. (To be strictly accurate there’s also another small block under this one which spreads the load a bit). I’ll try to attach a photo to show the view backwards from the front buoyancy…

    [attachment=0:jjvfd9ut]mast step.jpg[/attachment:jjvfd9ut]

    …you can see the double thickness chunk of timber (only partially varnished, seemingly) and the slight deformation of the grp moulding, which is however in good contact with the timber. To either side you can see the tabernacle, with the support block between.

    On Cockle we had a slightly different arrangement, as there was (is) a piece of hardwood between the grp moulding and the underside of the track, which may be what you need. But make sure everything’s sound below first.

    Must go.

    #10938
    Swiebertje
    Participant

    @Dave Barker wrote:

    Just to clarify about the mast pin – it’s just to assist with raising and lowering the mast (after towing or during bridge shooting).

    True if you are a cruiser.
    For racers the pin limits the fore/aft mast movement to 20 mm max. The rules require us to sail with the (6mm minimum) pin inserted (holes 16 mm maximum). It is one of many measures to ensure we all have the same options.

    @Dave Barker wrote:

    This link http://www.yachtsandyachting.com/downloads/?s=73&ArticleNumber=17 takes you to one of the online tuning guides.

    Actually it’s the mother of all other tuning guides. All others are copies from this article by Michael MacNamara, though many fail to credit the original author.

    #10947
    nickgiles
    Participant

    I have been following this discussion with interest as I suspect our mast has been resting on the mast pin with the result that the holes for the pin have become elongated. The sides of centre plug of the aluminium mast foot have become worn/eroded/butchered and are no longer level. I suspect that the weight of the mast is being taken by the cheeks of the mast foot resting on the sides of the mast foot track. Bigal implies that the weight should be taken by the plug and transferred to the floor of the mast track. That being the case it would be fairly easy to insert a hard plast fillet (chopping board?) into the slot in the mast foot plug allowing weight to be transferred to the floor of the track and lifting the mast enough to free the pin in the hole. Can anyone see any problems with this cheap fix?
    Cheers ,LizzieB 9922

    #10948
    Swiebertje
    Participant

    It is much easier to lift the track by adding a filler piece below the track. That way the packing piece does not need to have exact sizes and will last much longer as it is not exposed to wear caused by the mast foot sliding back and forth. It will be held firmly in place by the pressure the track exerts when it is screwed to the GRP again. However, with this solution you may want to use slightly longer screws or fill the screw holes with epoxy prior to refitting the track again, for the old screws will not go back as deep as before. Also epoxy takes care of waterproofing the screw holes. With some marks the screw holes may cause leakage of the forward buoyancy tank if not treated.

    If you are a racer you may want to repair your mast pin holes in the tabernacle to comply with the rules again. This is best done by two small pieces of 0.8 or 1mm thick stainless steel sheet material. Two square pieces of 25-30 mm should suffice. In the middle goes the 16 mm mast pin hole and in two of the corners small screw holes are drilled. Then the squares are glued (sikaflex) and screwed to the outer sides of the tabernacle with two screws each, above and below the mast pin holes. The SS squares limit the mast movement to the allowed 20 mm again and any scrutineer will pass your boat.

    #10949
    nickgiles
    Participant

    Many thanks for the helpful advice, as you say lifting the mast foot track would provide a permanent solution. As a matter of interest does it matter which bit of the mast foot takes the weight and transfers it to the mast foot track? Cheers, LizzieB 9922.

    #10950
    PeterW3035
    Member

    @nickgiles wrote:

    Can anyone see any problems with this cheap fix? Cheers ,LizzieB 9922

    Just check that the seating for the mast foot has not dropped and that the load is taken directly down to the “keel/hog”, see my earlier post.

    #10951

    Thanks once again for the excellent replies. I have not had time to get to the boat since the post.
    When i do i will take some more pics and try to document the repair.
    Can I ask is car filler an epoxy filler?
    And does anyone else have any other suggestions for packing pieces to go under the track? I am not sure if i will be able to purcahse ‘delron’ chopping board or if I could I am not sure that it will allow me to adjust the height quite as precisely as needed.
    Am I going to need anything other than a set of screwdrivers and a good pair of pump grips to remove my mast foot, to be taken home and cleaned up?

    Nickgiles I thought that I might be able to slot some packing directly into the track as you suggested. My concern is that this will raise the plug section higher than the track retaining bolt, potentially allowing for the foot of the mast to pivot or slide aft, without any restriction.

    Tim

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