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  • Oliver Shaw
    Moderator

    Agreed the 150 mm fairleads are rather large,  and the 85 mm are a better size.    Where did you manage to source them?   Well done.   That could be useful to other owners.

    In passing your photo of the 150 mm ones shows them set up on the wrong sides (alright,  I know that is just to illustrate the size,  but it is a good illustration of the correct and incorrect handing);   the photos of the 85 mm ones have them correctly handed.

    For what it is worth,  my cleat on A Capella is 120 mm overall length,  65 mm between pillars,  and that seems a very nice size.

     

    Oliver

    Oliver Shaw
    Moderator

    Good question!

    Agreed absolutely that for loads in tension the limiting factor if using woodscrews is likely to be the strength of the wood fibres around the thread of the screw;   this limits the grip which the screw can have.   In these circumstances though-bolting (with appropriately sized bolts and nuts and washers) should undoubtedly be stronger.

    However that is not the primary type of load here;   in this case the load is primarily in sheer,  not in tension  –  i.e. pulling across the screws rather than tending to pull them out,  i.e. horizontally rather than vertically.   And if the diameters of bolts and screws are equal there is no difference in strength for loads in sheer.

    There are however two matters glossed over in that last paragraph.    First,  the diameter of bolts used will be determined by the size of the holes in the cleat.   However for wood screws there are two different diameters;   that of the shank (if present),  which will be limited by the holes in the cleat,  and that of the core (i.e. inside the thread),  which will necessarily be smaller.    On A Capella I deliberately chose screws which were threaded for their full length (and thus no shank diameter),  because with only a limited vertical depth of the structure I felt it important to have as much thread gripping as possible  –  albeit that that decision may have been an excess of caution.

    Thus the effective diameter of the metal in the woodscrews is less than that of the bolts which might otherwise be used;   but conditions would have to be seriously extreme before the strength of the metal becomes an issue.

    The other matter glossed over is the statement that the load is predominantly in sheer;   I draw attention to the word “predominantly”.   There will of course be a slight “tripping-up” moment when the cleat is under load,  tending to lift the after end of the cleat off the deck,  thus putting the screws under some degree of tension as well as the load in sheer.   But that will be very small,  and in my case even less than for some cleats because (for other reasons) I happened to choose a low-profile cleat.

    Then there is the question of practicality and access for installing the cleat.    I could of course have brought in an assistant,  but I was essentially working on my own,  and was in my sixties at the time;   so I found it easier to use woodscrews,  rather than have to reach under the foredeck to manage a nut and washer while at the same time turning a screwdriver above deck.   And that is despite two generously sized access hatches.

    The final factor in my decision was that this was brand new construction,   using new wood;   so I had no anxieties over (suitably long) wood screws holding.   To date (17 years later) there have been no issues,  and this is despite the cleat being regularly removed in most winters so that the spliced painter can be taken off and put through the laundry.

    But I fully agree that through-bolting would be the gold standard,  if you can conveniently do it.

     

    Oliver

    Oliver Shaw
    Moderator

    That did at one stage concern me when I fitted out A Capella,   but I had rarely (if indeed ever) had a problem in any previous boats,  so I was cautiously reassured.

    However for cosmetic reasons my choice of cleat was a rather nice Herreschoff-pattern low profile one (in stainless steel,  my choice of material for all fittings for that boat),  and I did think at one stage that I might fabricate a nicely rounded and smoothed wooden capping piece to fit over it and mask it when not in use.    But with never even a single instance of the sheets fouling the cleat the capping piece just got pushed further and further into the background,  and in the end it never got made.

    I sailed that boat extensively for about 10 years before I passed her on to my godson,  and I have sailed her again on various occasions since then (including having her back on loan for the latter half of last year),  and never had a problem of sheets fouling in all that time.

     

    Oliver

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    Oliver Shaw
    Moderator

    Mmm  …   …

    110 mm.    Before you go firm on these,  place them on deck and see what you think.     Personally I think they are a little large for the size of boat;   the difficulty is that nowadays it is incredibly difficult to source this type of fitting in dinghy sizes.   My preferred length is 75 mm,  but given the near impossibility of now finding any at that size (I bought the last two from Reliance Marine back in 2006,   and even then I could obtain only conventional ones in the size I wanted  –  the type you have were unobtainable in that size) these may be an acceptable compromise.

    That apart,  they are a variant of what used to be called Swedish fairleads,  and which I gather are known in USA as skene cleats.     They are indeed a “crossed fingers” type,  designed to prevent the rope pulling out.

    You are absolutely correct in identifying which one goes on which side.    The base of the “hole” for the rope (which is inclined to the base of the fitting) should be as near fore-and-aft as possible,  so the one at the bottom in the photo is indeed the starboard one.    Then when you insert the rope you need to temporarily pull it sideways to get it to go in,  and it won’t come out accidentally.

     

    Oliver

    Oliver Shaw
    Moderator

    Also,  just in case you hadn’t already picked this up,  place your anchor fairleads absolutely as close to the stemhead as is reasonably possible.

    You want the anchor rode to “hold her by the nose”.

    And they may well be a handed pair,  so ensure that you put each of them on the correct side,  so that the warp leads in a fair line through them!

     

    Oliver

    Oliver Shaw
    Moderator

    I’m thinking of drilling a pilot hole, with a small counter-sink, pouring some CPES into the hole (to protect the now bare wood)

    I have never felt the need to do that,  but I can see your thinking.   However the purpose of the CPES would possibly be compromised by then inserting the screw.   A better approach might be to screw down the fitting (dry),  and then take it off again;   now you can pour the CPES into the already tapped hole.

    Some sort of sealant between fitting and deck is important,  but I do not have a view on the use of butyl tape for this.

    I used to use silicone sealant,  dispensed out of a cartridge,  but some years ago there was a vigorous discussion on the old Openboat site in which the general consensus was that silicone sealant eventually sets hard,  and is inflexible,  and also that it is almost impossible to remove later;   and polysulphide sealants were considered a better choice.   On my bigger boat I have therefore moved on to use a polymer sealant/adhesive called CT1,  at about the same cost as silicone sealant,  with good results thus far.

    However I am currently part-way through a refit on my erstwhile GP14 A Capella,   and when I last did the job (in,  I think,  2010,  immediately before she was exhibited at the Dinghy Show) I was still using silicone sealant.    When I came to take the fittings off this time I found that it was still flexible,  still adhering well (to both deck and fittings),  and still doing its job;   no sign whatsoever of water ingress.   So that is after about 12 years’ service.

    Removing it was not the impossibility predicted by others in that discussion;   a seriously sharp wood chisel initially used perfectly flat to the deck to slice through the cured sealant as close to the deck as possible,  with a slicing action,  followed by using the same super-sharp chisel used vertically as a scraper,  and keeping it entirely within the area covered by the fitting.    What little sealant was left was then removed in the course of sanding (orbital power sander,  with 180 grit).   Given sufficient care in using the chisel (and having it really sharp,  so that it could do its job properly) scraping of the varnish was almost non-existent,  and undetectable once the deck had been sanded;   and in any case that area is to be covered by the fitting again when I put it back.

    If you use a cartridge-dispensed sealant,  whether silicone or polysulphide or CT1 or whatever,  apply it generously to both the underside of the fitting and to the threads of the screws.    Then screw down the fitting,  and while the sealant is still in a liquid state remove the worst of the excess with dry kitchen roll.   Then remove the remaining excess with kitchen roll dampened with methylated spirit.   But removing the excess must be done before the sealant cures.

    Hope this helps,

     

     

    Oliver

     

    in reply to: Suggestions for securing boat to trailer for towing #25131
    Oliver Shaw
    Moderator

    Looks a good system,  at least while still new.     Time will tell how well the fittings on the cover wear.

    One modification that I had made on my towing top cover was a set of triangular “pick up” points,  with cringles,  along the length of it down the middle.   These are hooked up to the mast when towing,  to reduce the problem of rainwater pooling in the flat cover,  and eventually percolating down below.    See photo (apologies for pixelling,  just a very small detail from a much larger photo).

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    in reply to: Suggestions for securing boat to trailer for towing #25109
    Oliver Shaw
    Moderator

    A number of solutions have been developed for both your issues.

    Personally I think you have perhaps been a trifle unlucky with the rubbing strake being forced off;   it is not a problem that I have ever experienced,  whether on a brand new boat or a seriously old vintage one,  or indeed anything in between,  and I normally use fairly high tensions on my ratchet straps.   It could be that on your boat this was structurally weak at the time that it happened,  in which case if you have now done a good strong repair that might be the end of the problem;   but I can well understand you not wishing to take the risk.

    Some owners have made up substantial “strongbacks”,  as you describe;   but you have already identified the unsuitability of MDF for this.   Ordinary deal or other softwood will suffice,  but hardwood is probably more durable.   It would of course need to be slightly longer that the beam of the boat,  and would need to be adequately padded.

    You mention the boat moving on the trailer,  but it is not clear in which direction.   My boats have always had a very slight tendency to move aft,  albeit only a very few inches;   that seems to happen almost immediately I start towing,  but then no further movement occurs over even a prolonged journey.   However it probably does help that all my boats have been set up for cruising,  so I have a cleat on the foredeck,  and also anchor fairleads either side of the stemhead;  and I can take the painter forward from the cleat,  through one of the fairleads adjacent to the stemhead,  round the front of the trailer,  and then (as tightly as possible) back to the cleat by the corresponding route on the other side of the boat.   I suspect that the few inches movement is because of the unfavourable alignment of the painter,  and that small movement aft corresponds to loading up the painter to a working load for the journey.

    If that is not viable on your boat  –  as may well be the case for a boat set up specifically for racing  –  you could try a strap or rope running aft from the axle to any convenient strongpoint well aft in the boat;   looped through the transom scuppers,  for example.   That strap or rope would of course need to be padded where it crosses the decks,  and anyway else where it could cause scuffing.

    Supporting the aft end of the mast;    on older boats if you happen to have a rigid sheet horse you can place the heel of the mast on top of that,  with suitable padding,  and lash it well down.   However with the completely clear stern deck which has been the most popular configuration for many years now,  possibly the most convenient solution is a vertical support mounted on the rudder hangings;   that can also hold your lighting board and number plate,   or indeed you can make your own unit which combines lighting board and number plate and mast crutch (and the all-important padding) in a single unit.   (See photo)  But if you do go hanging things on the pintle and gudgeon,  do make sure that they are properly through-bolted,  and mot merely secured by wood screws.

    Hope this helps,

     

    Oliver

     

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    in reply to: Two-pot polyurethane paints #25104
    Oliver Shaw
    Moderator

    Ah;   found some data,  and it is much as I would have guessed.

    A 2005 report from the Health & Safety Laboratory,  on experiments to determine airborne isocyanate levels and biological effects from mixing and from brush and roller application.

    https://www.hse.gov.uk/research/hsl_pdf/2005/hsl0560.pdf

    Summarising the results,  in most instances no contamination was detectable,   but they do provide estimates for “LOD” values  –  not clear what the abbreviation means,  but the units correspond to those of the maximum exposure limits set by HSE (effectively the density of the dispersed isocyanate contamination in the air)  –  and these are single figures (migrogram per cubic metre,  4 for brushing,  5 for mixing,  8 for rollering),  which are very substantially less than the maximum permitted exposure levels (70 microggram per cubic metre for the short term (15 minute) and 20 for the long term (8 hour) exposure durations.

    For the biological monitoring,  in all cases there was nothing detected.

    Their overall conclusion was that there was no detectable airborne contamination of isocyanates,  but there was potential for dermal contamination  –  particularly with mixing and rollering,  less so with brushing  –  as the paint dripped onto the protective gloves.    The nil detections in the biological monitoring indicated that the PPE used was adequate to prevent exposure.

    An air-fed visor was used for all operations.

    I am somewhat relieved,  and this tends to confirm my suspicions that the ban is the result of “an excess of caution”.    I shall continue to use 2-pot paints and varnishes for as long as I can obtain them,  including by modest stockpiling;   but I shall wear gloves (which I tend to do anyway for painting operations),  and I shall consider eye protection and consider some kind of face mask.

    Oliver

    in reply to: Two-pot polyurethane paints #25103
    Oliver Shaw
    Moderator

    From a strictly lay perspective,  my understanding (and expectation) is that the big danger with such paints arises when spraying them;   and that danger is presumably much exacerbated for professionals who are exposed on a daily basis.       In such situations appropriate safety precautions have to be adopted,  and appropriate safety equipment used,   but I understand that the equipment and the protocols for this are now very well developed and understood.

    However for the amateur who is not spraying the material,  but applying it with either brush or roller,  and doing the job only infrequently,  I really do wonder whether a total ban is “an excess of caution”.    Does anyone on here have the expert knowledge to comment?

    Even given that these paints are now in the process of being withdrawn from the market the question is not academic:   on the one hand do we now immediately and urgently cease using our 2-pot paints altogether,  or on the other hand do we stockpile for future use while we can still obtain them?

    And,  if we are to continue using them (subject to availability),   do we need to wear protective gloves and breathing masks and eye protection?    Or is the risk,  for relatively occasional brush or roller application,  so small as to not be a problem?

    I do note Bruce Idleman’s comment that these paints are still readily available in North America,  with both DIY and Professional versions being listed on the company’s website (although spraying is specifically not advised for amateurs),  but that the ban this side of the Atlantic appears to be imposed by the EU,   and that the manufacturer may perhaps be applying the change to the UK as well in order to simplify their marketing.

    Almost all the information I have been able to unearth in an internet search this morning has referred specifically to spraying.    The one solitary mention of brushing or roller application slipped this in without comment in a list,   in the same context as spraying.

     

     

    Oliver

    in reply to: Two-pot polyurethane paints #25102
    Oliver Shaw
    Moderator

    Reply received today from International Paints’ UK Technical Sales Advisor, UK Yacht:

    We have had to cease selling Perfection to the public because of isosyanates being banned for public use.

     “We do not have a 2 pot for your use coming out in the near future.

     “Sorry”

     

    Oliver

    in reply to: Two-pot polyurethane paints #25101
    Oliver Shaw
    Moderator

    To update my original post,  I see from International’s website that both Perfection and Perfection Plus are now shown as “Retired” products,   although it seems that the “Pro” versions are still live.

    Bruce Idleman tells me that both products are still readily obtainable in North America,  and suggests that the problem here may be compliance with EU environmental legislation,   coupled with perhaps a commercial decision to not not have a separate product range just for the UK.

    I have today emailed the company to enquire whether they intend to introduce replacement products,  and I have told them that I am fairly visible on a number of sailing forums and that if they have any news which they wish to share this is a bit of free publicity for them!    (The carrot rather than the stick approach!   I will update the forums anyway!)

     

    Oliver

     

    Oliver Shaw
    Moderator

    An encouraging number of views.

    It would be even better if some of those, or even just one of them, resulted in an offer to take her on!

     

    Oliver

    in reply to: Building up 0ne pack Varnish. #25022
    Oliver Shaw
    Moderator

    The most authoritative answer probably comes from the manufacturers,  and I suspect that it may perhaps depend on exactly which one-pot product you have in mind.

    International Paints’ email address for technical queries is iyp.uk@akzonobel.com

    For my favourite one-pot varnish,  Schooner,  the instructions in the Data Sheet are to sand between coats.    The technical data sheet is here: https://www.international-yachtpaint.com/s3/documents/TDS/Schooner_eng_A4_20191017.pdf?_ga=2.174862626.1877383473.1667120155-451229013.1667120155

    Their website is here:  https://www.international-yachtpaint.com/en/gb/boat-paint-products

    Hope this helps,

     

    Oliver

     

    in reply to: Timber for mast step #24975
    Oliver Shaw
    Moderator

    Iroko is also a very highly respected boatbuilding timber.

    Laminating from thinner pieces can be excellent practice,  and especially if you cut the pieces out of a single strip and then turn them end for end before laminating.   This reduces any tendency to warp.   But I would not expect this to be necessary in this application.

    Interesting the conflicting views on CPES.    I presume that the low viscosity solvent is to enable it to penetrate effectively.    Possibly choose CPES when penetration is needed,  inclujding for priming before varnishing,  but WEST (or equivalent) for strength when bonding is required.

    An added point of information is that I get the impression that it is a wood-based rather than petroleum-based epoxy.

    Oliver

Viewing 15 posts - 91 through 105 (of 708 total)