Latest News: Forums Technical Mast Step renewal

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  • #4353

    I purchased a refurbished Moores Mark 2 GRP Wayfarer 7593 earlier in the year. I have used the boat extensively through out the summer. When I took the mast down on Sunday I noticed that the piece of wood into which the mast step is screwed had completely disintegrated through rot. The metal mast step simply fell off when I removed the mast. The 2 screws which have held the metal mast step on to the wooden plate simply fell out. I subsequently removed the 3 stainless steel screws that went through what was left of the wooden plate into the floor of the tabernacle.

    With what was left of the wooden plate it is almost impossible to get exact dimensions particular in terms of thickness. Is there a standard thickness for the wooden plate so I can replace it again in wood or better still does anybody have any experience of replacing it with some kind of nylon/plastic to ensure the problem does not occur again. Ideally I am looking at buying a replacement plate and simply screwing it on rather than having to make one as I am not brilliant at DIY which is why I bought a refurbished boat in the first place!

    Any advice would be greatly appreciated.

    #10319
    Swiebertje
    Participant

    The bolt holes in the mast and tabernacle are the reference from which a mast is measured, they should line up. Unfortunately the length of mast below the bolt hole varies. Also the holes in the tabernacle are not always in the intended location. The class rules allow some variation. Line the bolt holes up using thin filling pieces. Once the holes line up perfectly measure the thickness of the fillers used and make a new filler plate of that thickness. I made mine from some Delrin, cut from a Delrin cutting board. (Most people would call it nylon but it isn’t). The advantage of Delrin is it does not rot like a wood filler plate. These cutting boards are available in household shops or your local supermarket. (Or use the one from the kitchen and tell the misses……..).

    Don’t screw the mast step to the filler plate and the filler plate to the boat, that construction is no good. Screw the mast step directly to the boat, that ensures all forces from the mast are directly transferred to the hull rather then via the filler plate. You don’t need to fix the filler plate at all. With some decent screws it will get stuck for ever between the mast step and the hull when you tighten the screws. There should be a solid piece of wood below the GRP that allows the use of long screws (5 x 60 or longer).

    Before you fasten the mast step and your new filler plate you may want to fill the old holes with some thin epoxy. After it has thoroughly set you can be assured the new screws will hold like in a brand new boat. Make the holes in the filler plate slightly larger then the screw diameter, this is to avoid the screws biting in to the filler plate and preventing a tight fit between the mast step, plate and hull. While the screws are not yet tightened the plate should be able to move around ever so slightly. In the hull, drill the screw holes to the core diameter of the screws. 5mm screw – 2.5mm drill. Try 3mm if you have to use too much force tightening the screws. To avoid cracks in the gel coat you may want to drill the top of the screw holes with a 6 mm drill, but no more then 2 mm deep! And to prevent water from leaking in to the buoyancy tank, use some Sikaflex in the screw holes. Don’t be afraid to use liberal amounts of Sika as it will also glue the the filler plate to the boat and mast step, providing some extra strength.

    #10322

    Thank you very much. That’s perefct.

    #10576
    Anonymous
    Inactive

    I have a similar issue with the wood block at the base of my mast now well rotted. However mine is a Mk1 grp with the early gold anodised mast – this has no interlocking mast foot and step, instead the mast foot is a flat base that simply rests on this piece of wood.I feel this design is fundamentally flawed as any epoxy/varnish on the block simply wears away and quickly exposes the wood to the elements. Since the wood is now rotten the mast rests only on the pivot pin and is making some awful clonking noises when tacking ( or at least I hope thats all it is !) so even replacing with a Delrin block would probably soon see that worn.

    I therefore plan on taking out the old mast foot and shortening the mast from the bottom by an approporiate amount in order to fit one of the new Selden composite mast feet and matching step. This will remove the need for a wooden block and get a really positive connection between the mast and the center of the boat.

    The problem I can forsee is that it will be difficult if not impossible to get to the two bolts in the step that are designed to prevent forward/aft movement of the foot of the mast. My instinct says that these are not necessary on the Wayfarer as no such system was there originally and to include them would make lowering and raising the mast considerably more difficult and impossible while underway ( for shooting bridges etc .)

    Has anyone else done this and are there any issues or thoughts on the following points or anything else I havent considered :

    Are the fore/aft foot bolts required?
    Should the step be mounted directly to the hull or is a spacer preferred for any reason ?
    WIll the prevention of abeam movement at the foot create excess stresses anywhere else?

    #10578
    Robin
    Member

    @winsbury wrote:

    I therefore plan on taking out the old mast foot and shortening the mast from the bottom by an approporiate amount in order to fit one of the new Selden composite mast feet and matching step. This will remove the need for a wooden block and get a really positive connection between the mast and the center of the boat.

    I’m a little unsure what you mean by “This will remove the need for a wooden block” …

    On the Mk1 GRP, there is a wooden block under the fibreglass top that is formed by the extension of the centreboard case. This is screwed or bolted into the brothers (the verticle parts fo the tabernacle) to transfert the weight of the mast through the brothers to the keel. Im not sure which bit of wood it is that you are hoping to get rid of .. the one under the fibreglass? I hope not, thats really needed to fix the brothers firmly etc.

    On mine, as in the case of many others, that bit of wood rotted away, leaving the step just sitting there.

    I replaced the (now rotted) bit of Pine with a nice lump of hardwood, carefully sized and packed with well wetted fibreglass mat. You ,ust make certian the weight of the mast sits on the foot, and the foot is sitting on a block of wood (under the fibreglass) that is formly bolted or screwed to the brothers to take the weight directly to the floor of the boat.

    #10579
    Dave Barker
    Keymaster

    You need the bolt immediately behind the mast foot, but not one in front, which would just make it hard to lower the mast, which we all need to do from time to time.

    The “plug” in the bottom of most masts has a central portion (like a tenon in a mortise and tenon joint) which locates in the metal channel that is usually fixed to the top of a wooden block that in turn transfers the mast load to the boat, via the lower extension of the tabernacle. (This wooden block is on top of the fibreglass moulding, to clarify).

    You can calculate the thickness of the wood required to replace this block by measuring the distance from the very lowest part of the mast foot to the centre of the hole through the mast which takes the pivot pin. Allowing for the thickness of the mast step channel (a few mm), this should be the same distance as from the top of the new wooden block to the centre of the holes in the tabernacle which also take the mast pivot pin. If you’re not too confident of your calculations just play about with some scraps of wood or the like.

    To determine the shape of the block “on plan” just make a template from cardboard. Once you’re happy with it you could even use the template to obtain the block itself, by taking (or sending) it to a friend/colleague/joiner/boatbuilder etc., but I can’t think that it’s a complex shape, from memory. Get a hardwood block – mahogany or similar.

    #10580
    Anonymous
    Inactive

    The wood I was referring to is a packing piece immediately under the foot of the mast which sits on top of the fiberglass and not the main block that the screws go into which is underneath. As far as I can tell at this stage the piece between the brothers is still solid but I will check it and replace if it proves necessary.

    Thanks for the suggestion of putting the aft most bolt in, thats a good idea as it will prevent any possibility of the mast over balancing forward when erecting and I think may still be accessible ( just ). I guess that it should be just touching the mast so that when underway the mast will be pressed against the bolt to transfer even more of the load to the keel.

    The new style mortice and tenon style composite foot that I have to replace the existing flat foot and wood packing piece is too large to fit without reducing the length of the mast a little. I suppost the only remaining question is should I shorten it by ‘just enough’ which requires a very accurate measurement but would result in the new step being fixed directly onto the fiberglass or to cut or by a ‘bit more’ which would require a new packing piece between the new step and the fiberglass which requires the extra process of making a perfect sized packing piece (I’m not sure there’s any advantage to doing it that way though with my hacksaw skills being less than perfect may well be what I end up doing.)

    #10581
    Dave Barker
    Keymaster

    OK, so we’re talking about the same piece of wood. I would definitely not try to fix the channel (the “mortise”) directly onto the fibreglass. Use a hardwood packer, either made in advance, or, if you prefer, made after you have fitted the mast plug (with the “tenon”), which gives you a second chance to adjust the precise height relative to the pivot hole. The packer should end up at least 15mm thick so as to have enough intrinsic strength that it doesn’t split.

    If you’re not too confident with a hacksaw, just cut off a bit less than you calculate that you need to, then file off the rest. But this will quickly become tedious! With a new blade, adequately tensioned in the saw’s frame and with small enough teeth – look for a high tpi (teeth per inch) figure; at least 24 – you should be able to make a good job of it. I would use some tape – electrical, masking etc. – around the mast as a visual guide for the cut, to ensure a nice level result, but there’s always the file to tidy up any burrs. A half-moon file will tidy up the inner edge nicely if you have (or can borrow) one.

    I’m sure I don’t really need to ask, but the new plug does fit the mast profile?

    #10582
    Anonymous
    Inactive

    Great advice – the tape idea is excellent – my usual problem is wandering slightly off course when hacksawing so that will help me enormously.

    A packing piece it is then; I have some suitable marine ply so will make up a block and epoxy & varnish it against UV as the base for the new step so it should last a long time or I might just take a hunt round the kitchen for some Delrin when the missus isnt looking.

    Yes I have the correct foot – offering up against the old one it looks perfect: its one of the metal cast ones that Selden still supply for these older Proctor masts and fits the newer composite channel beautifully. Getting the old foot out looks like its going to be fun though as it looks well seized. I may be able to organise it so the cut is slightly above the inner part of the old plug, failing that it will be lots of wd40 and patience.

    More anon

    #10583
    Colin Parkstone
    Participant

    When cutting a mast tube or any round item the tape method is good but i would try and use a card or stiff paper that is wider than tape. If it is about 4in wide or more and long enough to rap around the tube, one and a half times or more the better.
    This way you can put the edge your going to use to mark the cut line, over itself and beyond, making sure the top marking edge is on top of itself all the way round. That then will make sure the line is not wavy around the tube !
    Did I put that right??
    CP

    #10586
    Dave Barker
    Keymaster

    Card trumps tape!

    #10682
    Anonymous
    Inactive

    Job done :

    I installed the new mast step on top of a Delrin spacer as suggested previously and it certainly seems more than tough enough. Heating the newly cut edges slightly in a flame and then pressing against the metal of my stainles steel sink left a really clean polished finish ( no saw marks ) that wont let dirt build up. I guess you could use glass or any other flat cold surface.

    Removing the old foot was incredibly difficult, it was very firmly in place due to build up of corrosion internally. After removing the rivets and heating it gently with a blowtorch and a LOT of hammer and chisel work it eventually came out albeit mangled well beyond re-use.

    As for cutting the bottom of the mast, I decided on using a precision mitre saw with the high toothcount and very deep blade. Propping the mast level and positioning the guide along the front of the mast correctly got me a perfect 90 degree cut that was completely straight, as a result it wasnt necessary to mark all around the mast , only to mark the starting point for the cut. The result was so clean it hardly needed any tidying up to debur. The amount of mast removed got rid of the portion with the worst of the corrosion and the old rivet holes. I fully recomend this method as even if you have to pop to Wickes and buy one of these baby’s they’re much cheaper than a new mast and will be handy for plenty of other jobs.

    The mast now sits beautifuly firmly on the new mast step and the pivot pin is free to move, I’m very happy with the result.

    I could have used a thicker Delrin spacer which would have meant the mast cut could have been raised to just above the old mast foot so it would not have had to have been removed. I dont think I would do it this way by choice but when the old foot was refusing to budge it was an option I thought about.

    #10683
    Dave Barker
    Keymaster

    Well done – sounds like a very good result!

    #10688
    Swiebertje
    Participant

    @winsbury wrote:

    it would not have had to have been removed.

    The beauty of the English language. 6 verbs in a row, I love it!

    #10689
    Anonymous
    Inactive

    I can do better: imagine a sign for a pub call the Pig And Whistle. Now imagine describing to the sign writer you want the space between the words to be made larger – you might say “the spaces between Pig and And, and And and Whistle are too small.” Five identical conjunctions in a row; English is indeed magic ! My apologies though; there’s every possibiliy I didn’t punctuate that correctly; it was in a punctuation test from school that I remember failing so please forgive me.

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