Forum Replies Created

Viewing 15 posts - 1 through 15 (of 699 total)
  • Author
    Posts
  • in reply to: Rudder down haul shock cord #27151
    Oliver Shaw
    Moderator

    Drilling a hole is one very good way of doing it.

     

    Oliver

    in reply to: Rudder down haul shock cord #27149
    Oliver Shaw
    Moderator

    Bin the shockcord;   it was never a good system,  and there are better systems available nowadays.

    Replace with two separate control lines,  not elastic but there is no need to go overboard with high tech non-stretch materials such as dyeema;   standard polyester is fine,  around 4 mm.   One control line is an uphaul,  led to a standard clamcleat on the tiller;   the other is a downhaul,  led to a CL257 auto-release clamcleat,  also on the tiller.

    Adjust the tension on the pivot bolt so that the blade moves as freely as possible vertically,  but with no sideways sloppiness;   that is likely to be quite a fine adjustment,  which can be found only by trial and error.

    Hope this helps,

     

     

    Oliver

    in reply to: Removing rot from my transom. #27110
    Oliver Shaw
    Moderator

    Ah!   Found your post,  and photos;    for some obscure reason it was a hidden reply.    It appeared when I clicked on the “+1 hidden” link at the head of the page.

    I suggest that the first step is to investigate further,  by removing the paint.    Once that is done you can asses how extensive is the problem.

    I note first that the transom is painted rather than varnished,  and second that you are considering just putting a fibreglass patch on it.    Fibreglass applied over rotten wood is very unlikely to be satisfactory unless either the rot is treated or the wood replaced first.    However when you can see the extent and severity of the rot you can assess whether it is worth trying treating it with Smith’s CPES,  followed by a fibreglass patch (using a marine epoxy resin,  not an automotive polyester one;   the headline name is WEST System,  but there are others also).

    If when you have the wood exposed you decide that it is too far gone for that approach you could then replace the rotten wood with a graving piece.   Since the transom is painted,  the appearance under the paint is relatively unimportant,  so it won’t matter if the graving piece is a slightly slack fit and you use the epoxy as a gap filler.    That will make the job a little easier.   You might or might not then decide to sheathe the repair with fibreglass;   that decision will depend in part on your assessment of the job when the wood is exposed.

    Do remember that the area around the pintle is structural,  and may on occasion take significant loads.   Inside the transom you may need to reinforce the bond to the hog;  and it is possible that the timber there may also have deteriorated.

     

    Oliver

    in reply to: Removing rot from my transom. #27108
    Oliver Shaw
    Moderator

    We seem to have a technical malfunction.   I have just now received an email from the Forum saying “This area is the most concerning because it seems to go behind the rudder pintle, but there are a few small areas of rot around the edges”,   which suggests that there is an accompanying photo;   but no photo has come through,  and not even the text part of the message is currently showing on the Forum.

    Can you please check later in the day whether anything has appeared by then,  and if necessary try again.

    Please be aware that the maximum file size allowed is 512 KB,  so if your photo is bigger than that it will need resizing.

     

    Oliver

    in reply to: New Member and Highfield lever position #27104
    Oliver Shaw
    Moderator

    It would seem difficult,  but not impossible,  to rig a block (or blocks in the plural) to divert the halliard clear of the strap eye for the kicker.    And I can see that you entirely reasonably wish to avoid unnecessary chafe with the present arrangement.

    I can suggest several possibilities for you to consider,  and perhaps investigate further.    In no particular order:

    • Run the halliard inside the strap eye,  with the D (rather than the pin) of the kicker shackle through the strap eye;   when under load (i.e. with the kicker tensioned) I would expect that the shackle will then be just clear of the halliard.   Then,  with the shackle the correct way round so that the head of the pin is accessible (rather than jammed against the mast),  that may completely solve the problem.   But if you find it necessary (and it may prove not to be necessary) devise a means of holding the shackle in that position;  perhaps Araldite or other epoxy glue (there are many available),  or tape,  or whipping twine,  or whatever.
    • If you prefer to take the halliard outside the strap eye,  use a pair of locking pliers (a.k.a. Mole wrench,  a.k.a vice-grips) to bend the strap eye slightly;   either so that the edges are bent inwards,  so that the halliard slides over only a convex surface,  and/or bend the eye in profile so that it is fully out of the way of the halliard.    Or (with care) use a ball-pein hammer to bend it in profile so that it is clear of the halliard.
    • With the halliard outside the strap eye,  run the halliard through a short length of flexible plastic tubing,   and position that to cushion it against the strap eye before you tension the Highfield.
    • Again with the halliard outside the strap eye,  use a small piece of high density foam as a cushion between halliard and strap eye,  again putting it in place before you tension the Highfield.

    I may well think of other ideas later,  but I have to adjourn now as I need to leave the house imminently to take a Choir Practice.   I may well edit this reply later.

     

    Oliver

     

     

    in reply to: Removing rot from my transom. #27098
    Oliver Shaw
    Moderator

    Removing the transom and then reinstalling after repair is fairly major surgery,  but removal and replacement with new wood has very occasionally been done.   I would expect that removal with the intention of re-using the same transom after repair would be an even bigger task.   It is one thing to take out the old one without damage to the frame on which it sits or to the plywood,  provided the old transom can be sacrificed;   with care you can cut away the transom (whether using router or saw or chisel,  etc) without touching either the frame or the plywood,   but that will inevitably cut into at least the periphery of the transom,  so it will end up smaller than it needs to be.    One can then replace the entire transom with new wood;   but I am not clear about how one could get the original one out undamaged,  so that the same transom could be refitted.

    Just possibly a very fine oscillating saw used all round the edge,   and then used again inside the boat to separate the transom from the frame on which it sits,  and accept that when it is refitted there would be the width of the saw-cut all round the edge which would need to be filled with (preferably) a thin strip of wood.   Or alternatively with epoxy???    But that is no more than a best guess as to an approach,  and I am not wholly convinced that it would work.    And at the end of the day there is still that gap,  at least the width of the saw-cut,  all round the edge,  which at the very least would be a problem.

    Around sixty years ago I replaced the transom on a Firefly,  and I know of a couple of people who have done that or very similar jobs on the transoms of GP14s in more recent years.   But certainly when I did the job the old transom was being scrapped and a brand new one fitted.    Don’t underestimate how big a job it is.

    Whether an in situ repair is viable depends on your assessment of the damage,  but in most cases I would expect it to be the easier option.   And,  depending on the severity and extent of the dry rot,   a possible alternative to a graving piece just might be treatment  with a deeply penetrating epoxy product such as Smith’s CPES,  a wood-based penetrating epoxy which was originally designed for that very purpose.

    Can you post some photos,  please?

     

    Oliver

    in reply to: New Member and Highfield lever position #27096
    Oliver Shaw
    Moderator

    Not sure;    can you supply a photo,  please.

     

     

    Oliver

    in reply to: Fitting rowlocks/ oar length #27091
    Oliver Shaw
    Moderator

    Excellent!

     

    Oliver

    in reply to: Fitting rowlocks/ oar length #27089
    Oliver Shaw
    Moderator

    Steve,

    In an idle moment I looked at your profile,  and spotted the name of the boat.    That name rang a bell;   and coupled with a sail number around 9000,  and the Series 1 to 2 conversion  –  which is quite rare,  and based in the northwest,  I think I know the boat.    Did you buy her from Peter Johnson,  a member of Liverpool Sailing Club?

    That is my home club,  and when Peter was considering buying her I vetted the boat for him!

    Peter had joined the club a short while earlier,  declaring that he wanted to try out a number of different boats until he had decided which class to buy.   I took him out just once in A Capella,  and he was so delighted with her that he immediately declared that his search was ended;   his choice was a GP14.   I didn’t attempt to persuade him to try others,  because I am an enthusiast for the GP14 myself.

    Regards,

     

    Oliver

    in reply to: Fitting rowlocks/ oar length #27083
    Oliver Shaw
    Moderator

    The differences in likely shank diameters,  i.e. 12 or 13 mm,  or 1/2 inch (= 12.7 mm) can be significant.

    Although in deference to age (81) I have reluctantly retired from GP14s,  and have very happily passed A Capella over to my godson as an advance on his future inheritance,  I have recently refitted her for him.    After revarnishing the decks and replacing the fittings the starboard rowlock was fine,  but the port one was very stiff.    The obvious solution,  in default of a reamer,  was to re-drill the hole for the shank.

    I tried a 12 mm (metal) drill,  but it went in far too easily,  and achieved nothing.    I then tried a 13 mm drill,  but that would not pass through the hole in the socket plate.   However I am of an age to still have some pre-metric tools,  so I then tried a 1/2-inch drill,  and it did the job to perfection.    A Capella‘s rowlocks,  bought new in 2006,  very much in the metric era,  clearly have 1/2-inch (i.e. non/metric Imperial size) shanks.    Of course,  I could have saved myself a couple of trials had I bothered to get out the micrometer,  or the verniers,  and actually measure the shank  …   …

     

    Oliver

    in reply to: Fitting rowlocks/ oar length #27082
    Oliver Shaw
    Moderator

    If you ask Tim to fit the plates he will of course do the reinforcing.

    It is not a job that I have ever done myself,  but it is one that I would have been perfectly happy to do.    (Tim fitted the socket plates on A Capella,  since this was part of the build).    Sitting at home in my armchair(!) I would expect to do the following:

    • Measure up and mark the centres of the holes.    Double check these measurements;    the old adage is “Measure twice,  have a cup of tea,  then measure again;  then cut once”.
    • Offer up a piece of mahogany under the deck,   I suggest 3/4 inch to 1 inch thick,  very substantially longer and wider than the socket plate,  but precise dimensions not critical;   bond this in place with epoxy.    If underside of deck is bare,  or if it is coated with epoxy,  the new bond will be strong.    If it is merely varnished,  the bond will be the (uncertain) strength of the varnish,   so err on the large side with your choice of dimensions for the reinforcement.     One way to hold the reinforcement in place while the epoxy cures would be to drive a single screw into it from above,  screwing exactly through the marked centre;    once the epoxy has set you can remove the screw,  and when you then drill out the hole all trace of that screw will have been removed.   Preferably remove the screw before the epoxy has cured fully hard;   but if you misjudge and then find difficulty in getting the screw out a soldering iron applied to the head of the screw should soften the epoxy enough to enable removal.
    • The socket plates may have a very short downward protuberance around the hole;   to call it a tube would be too grand a term,  perhaps between 1/8 and 1/4 inch (3 to 6 mm) deep.    If so,  using a self-centring wood bit,  drill out to that diameter and depth  –  adding the thickness of the plate to the depth,  to enable the socket plate to eventually sit flush,  recessed into the deck.    If no such protuberance,  reverse the order of some of the following steps;   drill for the shank first,  using a self-centring drill,  then match the plate to the drilled hole,  using the drill bit as a mandrel for getting the plate in exactly the correct position.
    • Insert the plate into that hole (it will of course still be sitting proud of the deck at this stage),   line it up accurately fore-and-aft,  then use a Stanley knife (craft knife) to mark around the outside.    This will probably be a rectangular shape;   if you happen to have chosen socket plates of elliptical shape this really is making a lot of extra skilled work for yourself!   Take great care to cut exactly along the line of the plate,  and not to mark the varnish outside the plate.   You can afford to cut into the deck to fractionally more than the thickness of the metal plate.   Note that at this stage you have still not cut the hole for the shank of the rowlock;   that is left for much later.
    • Using a freshly-sharpened wood chisel,   remove  the necessary depth of plywood from inside the marked region,  taking particular care not to damage the deck outside that marked region.    It is vitally important that the chisel is really sharp.   Initially settle for making the hole very slightly too small;   it is easy to open it out further,  but impossible to do an invisible repair if you cut too much!    Aim to achieve a level bottom to your hole,  which will perhaps be about 1 mm deep.
    • Using the chisel and the Stanley knife as required,  open out the hole until the plate sits neatly inside the hole,  and flush with the deck.
    • Once you are satisfied with the fitting of the plate,  insert the securing screws.
    • The shank diameter will typically be either 12 or 13 mm or 1/2-inch (which falls between the two metric sizes).   Provided you have access to the correct size of drill bit (which may be a problem if it is 1/2 inch and you have only metric sizes),  you can drill through the socket plate,  and in that case the bit does not need to be self-centring;   either a wood bit or a metal bit will do equally well,  as the plate will keep it centred.
    • So,  with the plate fitted,  and screwed down,   drill through the hole in the plate for the shank of the rowlock,  provided you have the correct drill bit size.
    • However,  if you find yourself having to drill fractionally larger than the hole in the plate,   e.g. 13 mm for a 1/2 inch plate (just 0.3 mm over-size) you will need to take the plate off again,  and then you must use a self-centring wood bit;   a bit designed for drilling metal will be too prone to wander off the true line.
    • Now check the rowlock in the hole,  to test for a good fit.
    • Finally,  with everything fitted,  and working,  remove the plate again.   Varnish the bare wood.    Then refit the plate,  bedding it down onto your choice of sealant.

    Job done!

    It actually sounds more than it is;    if you are reasonably familiar with quality woodworking the job is not particularly difficult.    But accuracy at all stages is the name of the game,  and if you are nervous of your abilities then it is a job perhaps better left to a professional.

    If you happen to read these posts by email rather than on the website,  please be aware that this one has had several edits,   so do look up the latest version on the website.

     

    Oliver

    • This reply was modified 1 month ago by Oliver Shaw. Reason: Notification of edits
    in reply to: Fitting rowlocks/ oar length #27056
    Oliver Shaw
    Moderator

    Noting that this is a wooden boat (Series 1,  with the series 1 to 2 conversion done),  that you say you are nervous of cutting holes,  and that you want a good dinghy builder in the north-west,  I would recommend Tim Harper,  who is based in Southport.   He has in his time built some beautiful,  and somewhat bespoke,  GP14s,  including my own A Capella.    Last time we met,  at a Past Commodores’ Dinner earlier in the year,  he gave me the impression that he is now semi-retired,  and said that he no longer builds,  but still does repairs.

    It would be worth determining first where you want the sockets to go;    there is a lot of material pertinent to this earlier in this very string.

    Then decide on what rowlocks you want.    Metal is vastly stronger and more rigid than plastic,   so I personally would never have any confidence in plastic ones.   Galvanised are el cheapo,  and very strong,  but a bit “agricultural”;   you may feel (as I myself do) that to fit them to a beautiful wooden GP14 would deface the boat.

    The strength of Chrome-plated rowlocks depends heavily on the quality of the substrate,  which is likely to be either brass or die-cast zinc alloy.    I have heard mixed reports,  with some owners reporting fractures,  and others having had no problem.   Indeed there is one adverse report almost immediately preceding this reply in the same string.   However it is difficult to compare like with like,  as I have no information on particular brands;   and even for the adverse reports that I have heard in most cases I cannot recall what the substrates were.

    For my money the choice is either stainless steel or bronze (gunmetal).   Bronze are probably the easier of the two to obtain,  and are normally available from Classic Marine,  or other specialist classic chandlers (such as Marinestore.co.uk,  or Davey & Co.)   Stainless steel may require quite a lot of online searching,  but if you can find stainless ones (that you like) they will be amply strong and they will also be a good cosmetic match to the rest of your stainless fittings on the boat.

    It would be worth discussing this with Tim before you buy;   he may possibly have sources of supply,  or he may prefer you to source them and he will then simply fit them for you.

    The neatest type of installation is to have the deck plates (sockets) recessed into the deck so that the surface is flush;  and that also gives the most comfortable seating if you happen to sit on top of one of the sockets.   However if you opt for that you may find that you need to put a short collar on the stem of the rowlocks in order to lift them a little,  so that the oar does not scuff your varnished rubbing strake on the pull stroke.   I made my collars by buying a short length of stainless steel tubing of suitable diameter (again an internet search will bring up suppliers),  and then cutting it to length.    The length is not critical;   half an inch,  or 15 mm would seem a good length to try.

    Hope this helps,

     

    Oliver

    in reply to: Centreboard case questions. #27054
    Oliver Shaw
    Moderator

    Your query 4:    certainly not brass screws, under any circumstances.    Over time they will dezincify, and become very weak semi-porous and apparently crystalline copper screws, which are then useless.

    (I think this problem may perhaps not have been known at the time the early boats were built;   it seems to have emerged in the late fifties and early sixties when brass screws,  which had until then been widely used,  started failing for this reason.    I was at university in the early sixties,  racing Fireflies,  and we were forever breaking masts when the chainplates pulled off the hull because the screws failed   …   …   Far more is known today about the behaviour of alloys in the marine environment.)

    The appropriate choices are either stainless steel or bronze.   Bronze screws are more expensive than stainless, but are very appropriate to the age of your boat;   however the screws securing the case to the hog are never going to be seen,  so there you may as well use stainless as being the cheaper alternative.    You may wish to indulge in the luxury of bronze for screws which will be visible,  e.g. those securing the case to the thwart,  etc.    Bronze fastenings (and much else) are available from specialist chandlers such as Classic Marine,  or Marinestore.co.uk,  or Davey & Co.   There may well be others as well,   but I have not found them yet!

     

    Your query 3:    I suspect that someone has previously done some work on the boat,  at some point since she was built.     There is no great need for either the floorboard bearers or the frames to be routed into the case,  but it is not wrong to do so;  historically some professional builders did rout them in,  and other professionals did not.   The floorboard bearers are not structural,  and serve merely to support the floorboards,  but the frames are structural,  and serve to fix the shape of the hull,  and provide lateral strength.

    Only one of the actual frames intersects the case;   frame 3,  which is the frame that also intersects the thwart.   Any lateral weakness arising as a result of splitting that frame (because the case cuts across it) would seem to be amply compensated by the very considerable strength of the two quadrilaterals formed on each side of the boat by the two parts of that frame and the case and the thwart,  together with the fact that the thwart is a single and very stout piece of timber bridging those two quadrilaterals.   I suspect,  but cannot confirm,  that the cut inner ends of that frame are also glued and screwed to the hog,  albeit that this will be either side of the slot,  which will therefore at least help to fix the distance between them,  further contributing to a rigid structure overall.

    By contrast,  joining the two cut ends into the sides of the case,  however it is done,  would seem to be a joint involving end grain at each surface of the joint if traditional woodworking joints are to be used;     so that is never going to be a strong joint.   A modern epoxy fillet joint  –  or alternatively a wooden fillet joint (with horizontal grain at 45 degrees,  to avoid exposure of any end grain)  –  would of course be strong,   but that is not what we are discussing,  and I am not personally aware of any boat which has needed this modification,  although I think it very likely that some owners will have done it.   However my own assessment is that ample strength would seem to be provided elsewhere.

    Frame 2 is immediately ahead of the case,  and frame 4 is some little way abaft it;  so each of those frames has its own integrity,  not compromised by the centreboard case.

    So I would not worry about this apparent alteration to the way the boat was built,  unless it troubles you cosmetically.

    Hope this helps,

     

    Oliver

    in reply to: Centreboard case questions. #27053
    Oliver Shaw
    Moderator

    Thickness first;   the permitted range of thickness of the board is 13 to 20 mm,  so at 19 mm you are close to the maximum allowed,  which is good.

    As regards the interior space inside the case,  you will need at least some slack in order to allow the board to move freely,  and to have a reasonable chance of avoiding it jamming.   A particular concern is the risk of mud or sand or small stones getting drawn up into the case and causing the board to jam.    I happen to have my very early vintage boat in the garage (no. 64,  dating from 1951),  and I have just measured the interior width of the case at the top (the only place where it is accessible),  and found it to be 26 mm,  just very slightly wider than your slot (25 mm).    Given that the class was originally designed and built to Imperial measurements,  rather than metric,  those seems to be to be a very sensible pair of dimensions;   a gap of 1 inch (25.4 mm) and a permitted board thickness in the range 1/2 inch to 13/16 inch.      So my first thought is that this slot width is very probably right.

    If you wished to check further you could check against the plans,  available from the office.    But personally I would leave the slot width unchanged.

    I am mildly surprised at the chamfering of the sides of the slot,  which I don’t think is normal.   But I winder whether a previous owner has had problems with the slot gasket being drawn inwards as the board is retracted;   this could be an ad hoc solution to that problem.   This discussion is very much open to other people to chip in,  but in the absence of any advice to the contrary I would suggest cutting the slot with no chamfer,  and fit new slot gaskets under tension;    cut them longer than the required length,  secure one end (which will become the far end from where you will next be working) by means of a screw (driven through that end of the relevant keelband),  pull the gasket taut,  and while holding that tension drive in a screw at the near end (again through the keelband).    Then fit the remaining screws,  and finally cut off the surplus gasket.

    I suspect that this will be sufficient,  and that you will not have a problem of the gasket being trapped inside the slot;    but if that does happen then at that point you can consider chamfering the sides of the slot.   However I doubt whether you will need to do so;  but others may think differently.

    Hope this helps,

     

    Oliver

    in reply to: New Member and Highfield lever position #27024
    Oliver Shaw
    Moderator

    And if you are going for a new suit of cruising sails,  you might like to consider choosing tan,  rather than white.

    Many reasons,  starting with that it is a traditional cruising colour;   but in bright sunlight they also produce far less glare,  and (perhaps surprisingly) they are sufficiently different to enable your boat to stand out conspicuously from others on the water  –  which can be a safety feature.

    And as an added bonus they look marvellous;   see (four) photos of three different boats,   each with tan sails.

     

    Oliver

    • This reply was modified 1 month, 1 week ago by Oliver Shaw.
    Attachments:
    You must be logged in to view attached files.
Viewing 15 posts - 1 through 15 (of 699 total)