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  • in reply to: GP14 Centreboard Mk1 to MK2 #23781
    Oliver Shaw
    Moderator

    Tom,

    Thank you for posting that image;   and I agree that it does appear that there was once a (stainless steel?) vertical carrier comprising two straps,  one each side,  with a pivot between them at the bottom of the straps.

    I have the very vague impression that I have very occasionally seen that arrangement on some early GRP boats,  but only as a fully assembled system,  and I confess that I had forgotten it.   Could this be the Thames Marine version??

    What follows is my strictly theoretical suggestions for how that could replicated now,  starting from scratch,  but I stress that I am not familiar with the detail of how this was fabricated originally.

    It should be possible to make up a replacement,  out of stainless steel strip.   One supplier of strip is Just Stainless,   https://juststainless.co.uk/product-category/strips/   Alternatively,  if you are going to ask your friendly local stainless steel fabricator to do the metalwork,  they would probably have suitable strip in stock,  and all they would need would be a sketch,  with dimensions,  and a description.

    I do not know how the pin was originally placed and secured;   but if starting from scratch now there would seem to be (at least) three options to consider,   all three for a semi-permanent pivot pin,   which would effectively be installed before the centreboard is fitted,  and then left in place.    The centreboard could then have a slot between the pivot hole and the leading edge,  as with the series 2 centreboard,   so the board could then be slotted into place,  and the slot then closed with a fillet,  again as per the series 2 board.    That may well not be original,  but I would confidently expect it to work.

    The pin itself could in theory be fitted by machining a spigot at each end,  so that the holes drilled in the two strips are smaller diameter than the main body of the pin.    That would then give a guaranteed spacing between the two strips.   Then either the ends could be peened over,  or tack-welded (your local stainless steel fabricating firm would be happy to do this for you,  and also to machine the spigots),  or  –  somewhat questionably  –  bonded with Araldite.

    A fourth option would seem to be to cut screw threads in both spigot and holes,  but because of the very small thickness of the strips this would need to be a very fine thread,  and I would think that each of the other alternatives is probably easier.    However the screw thread approach would enable the assembly to be disassembled later;   but I doubt whether that facility would ever be needed.

    Whatever method is used for securing the pin,  it would seem to be a requirement of the construction that there should be no surplus weld or adhesive rounding off the inside corners,  i.e. the pin should have a constant diameter right up to the side carriers.  And there is probably little tolerance for excess material on the outside face of the carriers either.    Your fabricator may need to be briefed about those two constraints.

    Hope this helps,

     

    Oliver

     

    in reply to: GP14 Centreboard Mk1 to MK2 #23659
    Oliver Shaw
    Moderator

    Steve also makes some very good points;   but the first thing is to identify whether your boat is or is not actually a Mk 2.

    Can you upload some photos,  please,  showing the interior layout (including the buoyancy arrangements),   and the aft deck and the transom.

     

    UPDATE,  0610 21 April:   I apologise that,  10 hours after asking for photos,  I will not now be able to respond for some time if they do now appear.   I go into hospital for planned surgery on my right hand in an hour’s time,  and I will then be unable to do any typing for perhaps the next three weeks.    Didn’t think of that when I requested the photos!

     

    Oliver

    • This reply was modified 3 weeks, 6 days ago by Oliver Shaw. Reason: Update
    in reply to: GP14 Centreboard Mk1 to MK2 #23658
    Oliver Shaw
    Moderator

    Tom,

    There is some confusion,  because I believe you may be using the term Mk 2 incorrectly;    the Mk 2 boat is an early GRP boat,  built from 1969,  and I am not clear whether any were built after the Mk 3 appeared in 1977.    To the best of my knowledge it uses the same centreboard as the Series 1 wooden boat,  and no modification is needed.

    If however you mean that your replacement boat is a Holt Speed,  or later,  model,  with underfloor buoyancy,  the pivot is permanently bonded into the case,  and the board has a slot extending from the pivot hole to the leading edge;   and once the board has been fitted the open end of the slot is blocked off by an infill piece which (I think) is screwed in place.

    Although the underwater profile of both centreboards is the same,  my understanding (from Tim Harper,  when he built A Capella for me,  and advised me that the Series 1 centreboard which I had acquired would not fit) is that the upper parts of the centreboards are not identical,  and that the earlier type of board will not fit the later boat.

    Sorry to be the bearer of bad news!

     

    Oliver

    in reply to: Genoa Reefing on a Series 2 #23543
    Oliver Shaw
    Moderator

    If your new genoa is cut with a higher clew I would hope that you shouldn’t need those extra control lines;   I developed those when I was using a standard genoa on a modern boat with through-deck sheeting,  but once I bought my new genoa with a higher clew I never used them again.

    Incidentally I had never needed them with that same standard sail on my previous boat which had on-deck sheeting;   I just moved the genoa cleat forward a little as necessary.

    But if you do find that you need them,  I had a single line right across the boat,  via turning blocks below the deck,  and I had cam-type jamcleats on the underside of the cockpit coaming.

    Hope this helps,

     

    Oliver

    in reply to: Genoa Reefing on a Series 2 #23424
    Oliver Shaw
    Moderator

    There is no single standard for any GP14,  whatever the model.

    What most owners use is a single control line system  –  and I have known precisely one GP14 owner (and also one Cornish Shrimper owner) use a twin-line (endless loop) system,  and I strongly suggest that you lead the control line to a camcleat on the foredeck close alongside the mast.   Necessarily that will be not quite the centre of the boat,  but it will be near enough not to matter.

    In passing,  the endless loop system worked well on the Shrimper when I borrowed her,  but I have no first-hand experience of using it on a GP14.

    If you have washboards fitted you will need to either drill (and preferably bush) a hole in one of the washboards to allow the line to pass through,  or alternatively pass the line across the top of the washboard.   Personally I would not recommend the latter,  for reasons of chafe,  and of inevitable wear on your wood and on your varnish.    A hole drilled in the right place,  and bushed (with epoxy,  or otherwise) seems a far better approach.

    However I have known occasional owners with GRP boats get round the problem of drilling the (hollow or foam-cored GRP moulding) washboard by instead leading the control line to one end of the washboard.   They claim that it works well;   but inevitably that means that it is led to one side of the boat  –  and if that happens to be the lee side when you are unexpectedly caught out and urgently need to reduce sail in a hurry that could compromise your safety.

    I note that you reference Wayfarers in which the control line is led down the side of the centreboard case,  and cleated abaft the thwart.    That strikes me as an unnecessary complication in a GP14,   but the Wayfarer is a larger boat,  and it may be of benefit there when single-handing.   In my extensive single-handing in a GP14 I have never found any problems with having the control line cleated on the foredeck alongside the mast,  as far aft as possible.

    I can reach it easily when single-handing;   indeed if one cannot reach it one is sitting too far aft,  which is a very common fault when sailing GP14s.   When single-handing and sailing to windward one should be sitting either astride or abeam of the thwart or forward of it,  in order to keep the transom out of the water.

    When sailing two-up my crew can reach a cleat on the aft part of the foredeck easily.

    Hope this helps,

     

    Oliver

    in reply to: First time at the RYA Dinghy Show #23406
    Oliver Shaw
    Moderator

    Yes,  and yes.

    Two more hatches forward;   but I have no photos that show them clearly,  and I no longer have that boat.

    Self-bailers in the two pockets beside the centreboard case.    My understanding that that this is normal in Series 2 boats except for certain ones pioneered by Alistair Duffin (sometimes referred to  –  unofficially  –  as Series 2A) which instead of self-bailers have permanent drain slots direct into the centreboard case.   The latter modification is reputedly fine for racing,  but can be a problem if sailing with three adults aboard,  or with two adults plus cruising kit such as camping gear,  when the boat sits a bit lower in the water;   it has been reported that the permanent drain slots can sometimes then flood the cockpit floor.

    If you don’t have self-bailers fitted I would recommend that you consider fitting them.   They do a different job from the transom scuppers,  and in ten years of extensively cruising A Capella (and very occasionally racing her) I found that I used both.   The self-bailers were routinely used,  almost every time I sailed,  provided there was enough wind,  for getting rid of small quantities of water (spray,  waves breaking aboard,  water brought aboard on the feet,  etc);   the transom scuppers were used just three times in ten years,  to get rid of serious quantities of water following capsize  (two of the capsizes were my own,  and one was by a friend who had borrowed the boat).

     

    Oliver

    in reply to: First time at the RYA Dinghy Show #23363
    Oliver Shaw
    Moderator

    Yes,  it is normal.   It always used to be regarded as good practice to periodically ventilate the buoyancy tanks,  although I am not totally sure that it is so necessary when all interior surfaces are coated with epoxy,  and when there are absolutely no leaks from any cause.    I confess to having become lazy about doing it;   I must remind my godson,  the present custodian of the boat,  to do it  …   …

    The jury may perhaps be out on whether they are indeed strictly necessary,  but if there is any doubt at all about the integrity and continuity of the internal epoxy coating they are certainly then necessary.     And if you get any water into the tanks via the drain bungs,  or via damage,  ventilation then becomes important.

    I suppose also that it is difficult to be certain that your buoyancy remains totally dry if you are unable to inspect it.

    Certainly hatches are normal.

    I did find with mine that in the early days the hatches tended to leak,  but I solved this problem by sealing the threads before screwing them tight.   On some occasions I used heavy outboard grease to seal them,  and one other occasions I used PTFE tape;   both methods appeared to work,  and to produce a watertight seal.

     

    Oliver

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    in reply to: Building mark 1 – in New Zealand timber type #23347
    Oliver Shaw
    Moderator

    And to add to Windy’s query about Series 1 as against Series 2,   dare I suggest that the choice is not entirely one-sided,  and particularly so for cruising.

    Both are great boats,  of course;   that almost goes without saying,  and especially on this forum!

    One of the design intentions of the Series 2 was that it should be quicker and easier and cheaper to build than the Series 1;   having never built either of them I cannot make that comparison from first-hand experience,  but my understanding is that this is indeed the case.

    In terms of the finished boats,  the Series 2 has a number of benefits,  particularly for cruising.    It has massive buoyancy,  and in the unfortunate event of a capsize it is remarkable how rapidly it will then clear the hull of water once you right the boat and get her sailing;   if there is enough wind to have capsized you in the first place then you can expect to be able to sail her dry within about two minutes (and possibly less) of getting her righted again.   By contrast,  if you capsize a Series 1 boat you may well need to resort to a bucket to bring the water level down to a point where you can start to sail her dry;   my own experience of deliberately flooding a Series 1 with newly installed transom scuppers (in order to try them out) was fairly disastrous,  and my very rare subsequent capsizes were not much better;   and I have heard mixed view from others as to whether the transom scuppers actually work on a Series 1 boat.

    An unrelated added bonus for cruising is the commodious storage pockets along the sides of the boat.

    All that sounds a very strong hand in favour of the Series 2.   But  …   …

    First,  in the event of a capsize the Series 2 is very prone to inversion,  precisely because of the underfloor buoyancy.    Various developments have attempted to address this problem,  but whatever version is sailed I would strongly recommend carrying masthead buoyancy as standard;  the popular 9-litre masthead float will not provide enough buoyancy to prevent inversion   –  indeed it is not designed to do so  –  but it will buy time during which the competent skipper/helmsman can take the necessary steps to right the boat.   Inexperienced skippers may wish to opt for the 40-litre masthead float intended for training establishments.

    Second,  the underfloor buoyancy reduces the space between the thwart and the cockpit sole.   Personally I never found that a problem except for one situation;   if you wish to camp aboard  –  which I appreciate is firmly a minority situation  –  that reduced space makes it impossible to sleep aboard the boat underneath the thwart,  and it is necessary to rig some sort of sleeping platform above the seating instead.    By the same token,   in a Series 1 boat,  any small amount of water that comes in overnight,  via the transom flaps or otherwise,  remains below the floorboards,  so you can keep your kit dry;   in a Series 2 any such water flows along the cockpit sole to the self-bailer pockets,  and once those are filled any further ingress of water produces a wet floor,  so it can become more difficult to keep your kit dry.

    The above may possibly influence your decision whether to build Series 1 or Series 2.

    Finally,  a correction to the terminology;   the terms Mk1,  Mk2,  etc (up to Mk IVa) all refer to fibreglass boats;   the terminology for the different types of wooden boats is Series 1,  Series 2 (and,  I think unoficially,  Series 2a).

     

    Oliver

     

    in reply to: Building mark 1 – in New Zealand timber type #23345
    Oliver Shaw
    Moderator

    There is a very long history of successful boat building (including yacht building) making the best use of whatever timbers are available locally;   and it is entirely reasonable to try to identify which of the timbers available local to yourself are most suitable for the job,  irrespective of what the plans say.

    Although I would not normally recommend sending retail quantities of timber half way across the world,  it might be worth your while to have a look at the Robbins Timber website,  if only for an analysis of the characteristics of a wide range of different timbers;   Robbins Timber  https://www.robbins.co.uk/products-prices/marine/

    Another useful website if you are considering Douglas Fir might be Collars,  again for information on the characteristics of the timber,  rather than expecting to buy from them at that geographical distance.   They are leading mast and oar manufacturers,  and they use either Douglas Fir or Sitka Spruce,  the choice depending on the particular type of mast,  because the two woods have different characteristics;   http://www.collars.co.uk/uk_galaxy/info/1/masts/15/timber

    Also some information here on obeche;  https://www.woodshopdirect.co.uk/planed-all-round/obeche-timber/ .

    Also worth having a look at The Wood Database;  https://www.wood-database.com/wood-filter/.

    In regard to rot resistance  –  always obviously relevant for boat building  –  I note from the last of these that Douglas fir is rated as moderately durable,  whereas obeche is rated as poor;   so it is a little surprising that the plans specify obeche!

    My recollection of the early GP14s which I have owned in the past is that longitudinal framing (stringers,  chine pieces,  carlins,  etc.,  were all in a light-coloured wood which I tacitly assumed to be pine.   I cannot be sure about the kingplank and the carlins.    However I am absolutely sure that the knees were mahogany.

    Hope this is of some help,

     

    Oliver

     

     

    in reply to: Boom Tent #23281
    Oliver Shaw
    Moderator

    Welcome back!

    Sorry to hear about your parents’ medical issues.

    I don’t actually have any tent plans as such,  but on A Capella I have occasionally used a boom tent made by the previous owner of a Series 1 boat which I bought in 2004.   It is basically a simple A-shape,  with a modest extension forward of the mast,  and access/egress at the  stern;  see the photos.

    Securing the bottom of the tent is a compromise,  because I used it only occasionally,  and I did not want to deface my then brand new boat by fitting lacing hooks or other clips around the hull.    So instead of using lacing hooks or other fittings I used to rig a 6 mm rope around the hull immediately below the gunwales,  tensioned with shockcord,  and tie the bottom of the tent on to that,  doing the job that with a land-based tent would be done by guy ropes and pegs.   That works tolerably in light winds,  but typically some part of the bottom pulls away and lifts the girdle rope above the gunwale at some point during the night;  but in light winds that is tolerable.   I have never put it to the test in strong winds.

    Condensation is an issue,  and I think at least one pair of proper tent ventilators are essential;   this tent doesn’t have any.

    Headroom is very limited.   If I were still into camping aboard,  and were thinking in terms of a new tent,  I would be strongly inclined to go for a design which gave adequate sitting headroom across the boat.     That could be achieved by the use of athwartship hoops made from light fibreglass rods,  perhaps adapted from a commercial tent using that system.   I have also occasionally seen Wayfarers using tents supported by a pair of longitudinal ridge poles,  one either side of the boat,  mounted to the shrouds forward,  and on an athwartships bracket secured to the boom at the after end.    One obvious issue for either design is where and how to store the tent frame while sailing,  but other dinghy cruising sailors do manage that.

    It might be worth an enquiry to the Wayfarer Association,  and/or to the Dinghy Cruising Association.

    Hope this is of some help.

     

    Oliver

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    in reply to: Mast replacement (Speed GP14 14022 Selden mast) #23241
    Oliver Shaw
    Moderator

    Paul,

    Not to worry about the delay;  explanation accepted,  and I was perhaps a tad hasty.    But perhaps you can understand where I was coming from!

    Regards,

     

    Oliver

    in reply to: Mast replacement (Speed GP14 14022 Selden mast) #23228
    Oliver Shaw
    Moderator

    Paul,

    Was my prompt (and researched) answer to your apparently urgent enquiry of any help to you?

    By now,  my links to masts advertised second-hand must be considered out of date  …    …

     

    Oliver

    • This reply was modified 3 months, 2 weeks ago by Oliver Shaw. Reason: Update
    in reply to: Mast replacement (Speed GP14 14022 Selden mast) #23211
    Oliver Shaw
    Moderator

    Paul,

    Unfortunately your photos have not uploaded;  you need to reduce the file size and try again.

    However some general principles may be helpful:

    First,  contact your insurer;   without the photos I know nothing about what the damage is,  or the circumstances,  and likewise I do not know what valuation you have insured for,  but it is worth checking whether you have a valid claim.   If it is accidental damage,  and the replacement cost is within your insured limit,  you probably have.

    Second,  any major dinghy chandler should be able to source a replacement mast for you.

    • Sailboats.co.uk appear to have taken over from the now defunct Speed Sails  –  they describe themselves as a main dealer for Speed Sails,  and a page on National Historic Ships gives an address for Speed Sails which is the same as the address Sailboats.co.uk quote on their website,  although it is not even the same town as the address which they had in their heyday.   They list a number of Selden accessories for the GP14 but not the mast itself;   however don’t assume that the absence of something on their website implies that they cannot source it for you,  and since they are listed on the Selden “find a dealer” map I would expect that they probably can.   It is at least worth asking them..

    Third, the Selden website has a “find a dealer” service here.

    Fourth,   if for whatever reason a brand new mast is not an option,   have a look at the Classifieds on this site.   At the time of writing there is currently one listed.   Remember that a series 1 mast can be converted to series 2 if necessary (but not the other way round,  although for a boat as young as yours the latter will not be an issue);   the series 2 mast is 12 cm shorter,  because of the higher location of the mast step.

    Fifth,  it is worth doing a search on eBay.   There are 6 masts plus a complete boat currently listed here,  although I have not checked any of them out;   some may be a lot older than your mast,  and perhaps less suited to a modern race-spec rig.

    Sixth,  depending on what the damage is,  a repair might perhaps be possible.

    Hope this helps,

     

    Oliver

     

    • This reply was modified 3 months, 3 weeks ago by Oliver Shaw.
    in reply to: Kicker and Rig Tension #22946
    Oliver Shaw
    Moderator

    I do wonder whether on your older boat,  with that much rig tension,  and no mast steep conversion,  you are straining the hull by unduly depressing the mast step.   If so,  you could be heading for structural problems;   metaphorically pushing the mast out through the bottom of the boat.

    That much rig tension  –  on its own  –  will be generating somewhere around half a ton force downwards on the mast step,  before the wind loading even starts!      The boat was designed in 1949,  long before such high rig tensions became usual,  so it was never designed for these loads.

    It might be wise to settle for slightly less rig tension!

    As for liking your older boat;   if she is a bit special for you,  and especially if she is a wooden one,  go for it!

     

    Oliver

     

    in reply to: Kicker and Rig Tension #22944
    Oliver Shaw
    Moderator

    Thinking about this from a physicist’s perspective,  is the front face of the mast still in free air in the slot,  and thus free to move further forward,  or is it butting up against either the front of the slot or a chock?

    If the front face is still free to move forward then the kicker should have no effect on rig tension;   the forces are all internal to the mast/boom/sail/kicker system,  and the position of the hounds does not alter,  and so the tension on the shrouds should not alter.

    However it the front of the mast is prevented from moving any further forward the effect of high kicker loads must be to pull the hounds aft;  which will increase the tension in the genoa luff and reduce the tension in the shrouds.

    But I concur that if your shrouds are visibly loose,  other than the leeward one being a little slack when driving hard to windward,  then either there is something very odd going on or you are perhaps using excessive kicker.

     

    Oliver

Viewing 15 posts - 1 through 15 (of 580 total)