S2 6.7 Junk Rig Conversion

  • 21 Jun 2019 22:26
    Reply # 7592849 on 6872873
    Anonymous member (Administrator)


    Ingeborg’s maststep actually wasn’t so heavy, after all, but if you want to shrinkyours to half the weight of it, it is enough to crimp all dimensions with 20%. The plywood I used was either 15 or16mm thick  -  I don’t remember now.

    Just make sure the mast will never jump out of the step, or else...


    Last modified: 14 Jul 2019 21:26 | Anonymous member (Administrator)
  • 21 Jun 2019 16:33
    Reply # 7592231 on 7589014
    Arne wrote:


    PS: Check this: http://bit.ly/2sf2tsW

    Hi Arne,

    I have been studying your mast step and partners document for some months now. I have never considered any other way to build a mast step. My only doubt is if I should use the same total thickness on my S2 6.7 (998kg) as you did on your Folkboat (2150kg). I am not concerned about how much labor is involved. I am concerned about adding too much weight to the bow of my boat.

    In addition to the very helpful instructions I also enjoyed these comments:

    "With the sail finished (Jan. 2015), it was time to set to work on the hard bits."

    "to have a mast step come loose [...] would turn the big mast into the mother of all can openers. "

    When I was working on the sail it did not occur to me that the hard part was yet to come!


    Last modified: 21 Jun 2019 16:34 | Anonymous member
  • 20 Jun 2019 09:07
    Reply # 7589014 on 6872873
    Anonymous member (Administrator)


    this plywood maststep may not be the quickest to build, but it surely is strong, and you have the advantage of being able to move it a little on top of the base, to get the mast standing right. My present boat was afloat while I fitted the step, so the boat was only so and so level with me moving around on it.

    Four things may be of interest:

    ·         I rubbed the hull with a little angle grinder to make the epoxy stick as well as possible. (Edit: Wise from experience, I brought the vacuum cleaner on board with the angle grinder...)

    ·         I sealed the plywood thoroughly.

    ·         I made a drain notch in the mast step. Even with sealed plywood, I don’t want the mast to stand in a puddle of water. (so far the step has stayed bone dry, thanks to the mast coat).

    ·         I have later secured the mast from ever being able to jump out of the step.


    PS: Check this: http://bit.ly/2sf2tsW

    Last modified: 24 Jun 2019 22:20 | Anonymous member (Administrator)
  • 19 Jun 2019 22:34
    Reply # 7588409 on 7586679
    Anonymous wrote:

    Phil, if you are following along I would appreciate your opinion on how thick and wide to make the mast step. As you may recall the displacement of your ComPac is close to the displacement of my S2 6.7

    Is 6" tall, total, too much? Is 2" for the collar too much or too little? 

    I think I had six beveled layers of 1/2 inch ply for the base, enough to to have good contact area on its bottom and the beveled edges. The upper section that held the mast is probably 2 inches thick.  Brenda B’s hull is flatter than some so the bevels may be flatter with slightly more surface and contact area for the epoxy, first well coated (plywood edges soak it up pretty well) then glued with thickend epoxy. I also glasssed top edge of the base to the hull.  If I get out to the boat tomorrow I’ll double check.

  • 18 Jun 2019 23:44
    Reply # 7586679 on 6872873

    Phil, if you are following along I would appreciate your opinion on how thick and wide to make the mast step. As you may recall the displacement of your ComPac is close to the displacement of my S2 6.7

    Is 6" tall, total, too much? Is 2" for the collar too much or too little? 

    Last modified: 19 Jun 2019 00:47 | Anonymous member
  • 16 Jun 2019 22:28
    Reply # 7582802 on 6872873

    Thank you for the responses. I ordered a water level. I will plan on leveling the boat on the trailer using the bottom of the bootstripe and then make a fore-aft and port-starboard 'level' line on a bulkhead or some other place.

    I was thinking I should sail the boat with the original rig at least once before taking the existing mast off. But it keeps on raining! I am not against sailing in the rain but trying to learn how to step a mast and launching a boat for the first time in the rain seems like it could cause problems.

    Summer is short. I think I may skip the sailing this summer and stick to working on the conversion.


  • 12 Jun 2019 15:55
    Reply # 7574319 on 6872873

    If the scum line is anywhere close to following the boot stripe, I'd use the bootstripe.  Manufactures generally try to get that right.  You're going to be changing the center of gravity on the boat by moving the mast, but then you'll probably futz with the trim once its in the water - to match the boot stripe.

    Once you've adjusted the stands to get the boat level athwartship and fore and aft using the water-in-a-clear-hose trick, you can make 2 level lines on 2 interior bulkheads: one fore and aft, one athwartship.  Every week or two, slap the level up against them to make sure the boat hasn't settled. Mine moves about an inch between the spring and summer.

    Last modified: 12 Jun 2019 15:59 | Anonymous member
  • 12 Jun 2019 14:06
    Reply # 7574182 on 6872873

    Thank you, Phil and Scott D. for taking the time to respond.

    I imagine if I purchased a nice laser level I would find many uses for it on the boat and around the house. The price for the one you suggested, Scott, does seem reasonable. I am just not sure this is the best way to use my limited boat budget right now. I spent about 20 minutes rummaging around my garage trying to find a way to rig a plumb bob before I gave up and bought a 'real' ($4.00 Harbor Freight Tools ) one. I am trying to buy the best materials for the boat and rig. I have a hard time doing that and collecting more tools at the same time.

    After considering ACX exterior ply I decided to spring for actual AB marine grade plywood for the mast step. One sheet is sitting in my garage waiting to be made into something useful.

    I intend to follow the path that Arne made for us regarding mast step construction. I purchased 1/2" plywood. I am planning on 12 layers total to give me a 6" thick mast step. Also following Arne and Phil I plan to make the top 4 layers (2") a separate section for the final alignment.

    To Answer your question, Phil, I have no idea if the keel trunk is square to the waterline but it is a more or less straight and flat surface that I can use for alignment.

    I am not sure how I would eyeball the waterline on this boat. Should I use bottom of the vinyl boot stripe decal and assume whoever put that on used the true water line? Should I attempt to use the top edge of the bottom paint? It is old and not a straight and continuous line. I thought about using the top edge of the 'scum' (I need to clean the hull) as the waterline. But even using this I would have to assume that the boat was loaded evenly last time she was in a boat slip. What exactly is 'the water line' on this hull?

    I watched a video about how to make and use a water level. I will very seriously consider making one. If I can decide on what to call 'the' water line then this would be very helpful.


    Last modified: 12 Jun 2019 20:16 | Anonymous member
  • 11 Jun 2019 20:21
    Reply # 7572979 on 6872873

    For centering the mast step and deck opening, I found a plumb bob hung from a cup hook in a hole drilled in the cabin headliner to be most useful.  Once the right spot is found, then the thing just stays there - a constant companion in visualization.

    Along similar lines, if you have any intention of doing more significant interior modifications, this laser level thing has paid for itself a hundred times over.

  • 11 Jun 2019 15:35
    Reply # 7572383 on 7572206
    Anonymous wrote:

    Up next is a problem I didn't think about until I tried to measure for the mast center location. Some how I need to identify which direction, exactly, is 0 degrees straight up from the hull through the deck. I am planning to use the forward edge of the keel trunk for this reference. My idea is to strap a bubble level to the forward edge of the trunk and then adjust the trailer until this is as level as I can get it. After that I can use a measuring tape and plumb bob to locate the mast center. Does anyone have a different suggestion?

    Can you know that the keel trunk is square to the waterline fore and aft? I used a four foot level and eyballed to the waterline fore/aft and port/sbd to level the boat on its trailer. A much better way would be to use a water level, not difficult to make with some clear tubing.  I built the mast step as Arne did and shows in his write up on Ingeborg. It was in two sections with the step base built up and epoxied to the hull and the upper section,which holds the mast, fastened to the base.  With a smaller boat I felt fine with just screwing the sections together. Having just a couple of lag screws in when I first stepped the mast gave me to option of adjusting the step some.
    Last modified: 11 Jun 2019 15:51 | Anonymous member
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