S2 6.7 Junk Rig Conversion

  • 24 Feb 2020 12:05
    Reply # 8766239 on 6872873

    When I built Tystie, some of the tube work was too big for the anodising bath, so it got powder coated. Over several years, the coating started bubbling where the water had got behind it (the anodised tubes stayed good).

    Weaverbird has an untreated mast, and it is staying good above deck. A natural oxide film forms in the presence of dry air and the absence of any electrolysis; anodising is simply a speeded-up, controlled version of this oxidation process. Below decks in the forepeak, there is some salting on the surface due to a damper, stiller atmosphere, but I don't think it's doing any harm. For a better cosmetic appearance in an inhabited forecabin, it could be painted with etch primer then enamel.

    Sailing on a fresh water lake, there's little or nor reason to paint or anodise an aluminium mast.

    Last modified: 24 Feb 2020 12:08 | Anonymous member
  • 24 Feb 2020 01:32
    Reply # 8765569 on 8765208
    Anonymous wrote:

    I been procrastinating. Some more important things needed attention but honestly I think I have been lazy, too.

    Anyway it seems I need to order an alloy lamp post right now so that the 12 week lead time does not use up ALL of the summer.

    Does anyone have an opinion on white powder coat vs unfinished aluminum alloy?

    I think the powder coat would be good initially. I would expect less friction and fewer stains from oxidation. But in the long run I have no idea how I would refinish a powder coated mast once the original finish is warn through. 


    I prefer an unpainted mast.  It does not need to be anodised either.  Arion's mast was not anodised and looked fine after almost a decade when we parted company last year.  My new boat has a raw alloy tube that is 35 years old and looks just fine.  You will eventually have to repaint if you choose the powder-coated option, and there is the possibility of corrosion being accelerated if the powder coating cracks and moisture gets trapped behind. Though usually the paint either falls off or is worn off, and the remaining surface stabilises like unpainted alloy.  It just looks messy. 
    Last modified: 24 Feb 2020 01:35 | Anonymous member
  • 23 Feb 2020 20:21
    Reply # 8765208 on 6872873

    I have been procrastinating. Some more important things needed attention but honestly I think I have been lazy, too.

    Anyway it seems I need to order an alloy lamp post right now so that the 12 week lead time does not use up ALL of the summer.

    Does anyone have an opinion on white powder coat vs unfinished aluminum alloy?

    I think the powder coat would be good initially. I would expect less friction and fewer stains from oxidation. But in the long run I have no idea how I would refinish a powder coated mast once the original finish is warn through. 

    Last modified: 15 Mar 2020 16:52 | Anonymous member
  • 12 Dec 2019 23:30
    Reply # 8259382 on 8211324
    Annie wrote:

    You might find a multitool is a good choice for this job, Scott.

    I do not like spending money on tools and finding some place to keep even more stuff.

    But -- the multitool was a very good idea. It is amazing how it will cut through wood with just a little pressure but at the same time if you accidentally bump your hand it doesn't do any damage. I should have started with this. The de-coring part of the work is moving along much faster and with better results now.


  • 09 Dec 2019 18:05
    Reply # 8226190 on 8211324
    Annie wrote:

    You might find a multitool is a good choice for this job, Scott.

    Go for the oak, Scott, as long as it is seasoned.  (a) we are just talking trim here (b) John Guzzwell recommends it in his book (c) Tystie is trimmed out in oak and has had no problems with bits falling off. It supposedly has a reputation for not gluing that well: so has teak.  I've never (touch wood!) had a problem with either. 

    To ease your mind, just be more than usually scrupulous in ensuring that both surfaces are well wetted out first and maybe even wipe it with solvent.  If you look here, you will find more about gluing it from the Gougeon Bros.  But don't forget, you are not using it structurally.


    Annie,

    I am working on borrowing a multi tool or maybe buying one if I have to.

    The Epoxy Works Article that you shared was the same one that convinced me not to use oak and epoxy for structural work on the deck core.

    This is from the article:

    " [..] two factors, dimensional instability and high density, interact to result in the unpredictable performance of an adhesive bond. The grain strength of the oak is about the same as the adhesive strength of the WEST SYSTEM 105 Resin-based epoxy. When the oak changes dimensionally, there is a “tug-of-war” between the strength of the wood and the strength of the epoxy bond. Sometimes the epoxy holds and sometimes it doesn’t. [The flexibility of G/flex epoxies is what allows them to maintain their bond with oak—Ed.]"

    Scott.

    Last modified: 09 Dec 2019 18:06 | Anonymous member
  • 08 Dec 2019 07:56
    Reply # 8212144 on 6872873

    For major GRP cutting jobs, a blade edged with tungsten carbide grit is best. They can be found for both multitools and hand saws, and a store that sells ceramic tiles is a good place to look. For small jobs, you may get away with a HSS blade, but it will blunt quickly.

    I was assuming that the boat has some trim already, and you'd try to find something that was near to a match, or at least, pleasing to your eye. Species such as maple and poplar will need a good coat of epoxy, as water ingress would turn them black.

    For replacing the balsa, douglas fir will do fine.

  • 08 Dec 2019 05:52
    Reply # 8211324 on 8209644
    Scott wrote:

    I will plan to do this as well. I found my tiny hack saw. I think it should work for squaring up the corners.

    I started working on getting the core out with a chisel. Balsa is more difficult to break apart than I expected. I am happy it is not plywood.

    Do you have a recommendation for a hard wood to use? My first thought was oak. Then I read on the West System website that oak should never be used with epoxy. I can't seem to find any ash boards. Poplar looked good, but then I found people online saying it is no good for boats due to poor water resistance.

    The price of maple terrifies me. Hickory I have only found as flooring sold by the case.

    At the moment I think Douglas Fir seems like the best option for 'hardwood strips' even if it is not really hardwood. 

    You might find a multitool is a good choice for this job, Scott.

    Go for the oak, Scott, as long as it is seasoned.  (a) we are just talking trim here (b) John Guzzwell recommends it in his book (c) Tystie is trimmed out in oak and has had no problems with bits falling off. It supposedly has a reputation for not gluing that well: so has teak.  I've never (touch wood!) had a problem with either. 

    To ease your mind, just be more than usually scrupulous in ensuring that both surfaces are well wetted out first and maybe even wipe it with solvent.  If you look here, you will find more about gluing it from the Gougeon Bros.  But don't forget, you are not using it structurally.


  • 08 Dec 2019 01:52
    Reply # 8209644 on 8175658
    David wrote:

    I would also cut away the radii in the corners. If the corners are square, it will be easier to bond on pieces of hardwood trim to cover the messy edge.

    I will plan to do this as well. I found my tiny hack saw. I think it should work for squaring up the corners.

    I started working on getting the core out with a chisel. Balsa is more difficult to break apart than I expected. I am happy it is not plywood.

    Do you have a recommendation for a hard wood to use? My first thought was oak. Then I read on the West System website that oak should never be used with epoxy. I can't seem to find any ash boards. Poplar looked good, but then I found people online saying it is no good for boats due to poor water resistance.

    The price of maple terrifies me. Hickory I have only found as flooring sold by the case.

    At the moment I think Douglas Fir seems like the best option for 'hardwood strips' even if it is not really hardwood. 

  • 04 Dec 2019 15:28
    Reply # 8175658 on 6872873

    I would also cut away the radii in the corners. If the corners are square, it will be easier to bond on pieces of hardwood trim to cover the messy edge.

  • 04 Dec 2019 02:24
    Reply # 8170666 on 8163493
    David T wrote: I would rather chisel out the core to a depth of 1 1/2" all the way around, bond in hardwood strips in to fill that cavity, then bond and bolt the plywood on top. Having done that, an extra two squares of thick plywood of smaller size, surrounding the tabernacle, will transfer the load satisfactorily, to the larger square.

    Thank you. This seems to be a very good plan. Hopefully after I chisel out 1.5" I will have solid dry core all around.

    Your help is very much appreciated.

    Scott


       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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