Maxi 77 junk rig conversion

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  • 26 Mar 2024 07:34
    Reply # 13334726 on 13226713

    Thanks Arne!

    I had this in my mind, but was glad to be reassured by practical experience.

  • 25 Mar 2024 08:50
    Reply # 13334154 on 13226713
    Anonymous member (Administrator)


    don’t make a big problem out of a small one.
    The bending moment in a mast is highest at the partners and next to nil at the ends.
    You may well drill a hole in the mast just above the mast step. I drilled two 8mm holes and ran a rod right through the mast . The rod was then lashed down to the mast step on both sides of the mast. No big deal.

    Keep up the good work!


  • 25 Mar 2024 07:15
    Reply # 13334142 on 13226713


    the work is in good progress, and this week I will probably finish the mast step. While preparing this step, a question came to my mind: How is a possible upward movement being prevented with the "Arne-style-maststep"? It would not be too nice I guess to drill a hole through the mast above the step, to fasten a steel angle there...

    Thanks for any comments on this!


  • 21 Feb 2024 19:53
    Reply # 13318937 on 13226713

    Also, thanks Graeme and Kevin for sending me the missing magazine #66! I found the article regarding the grp mast collar quite interesting. However, I have something else in my mind, but will post it in the technical forum

  • 21 Feb 2024 19:50
    Reply # 13318935 on 13226713

    Hi Arne,

    thanks for sharing your experience. I'll will try and stick will plain aluminium then. If necessary, I could still paint it after one season.

    Your suggestion of the stopping line is as brilliant as simple. Much appreciated!



  • 20 Feb 2024 18:49
    Reply # 13318231 on 13226713
    Anonymous member (Administrator)


    Congratulations, so far.
    As for aluminium and corrosion, I have used aluminium in the 60-series; 6060, 6063 or 6082. These are corrosion resistant enough without any treatment. However, it may be an idea to paint an aluminium mast as it tends to stain the sail black in that position.

    The diagram below shows basically how I tie on the halyard’s slingpoint on the yard these days. The sort of lashing is not critical. The thing is to remember to fit (tape on) that stopping line to the underside  -  before starting the lashing. The stopping line prevents the slingpoint from creeping any more  -  I only fitted it a couple of years ago. The stopping line is simply tied to the first available little webbing loop at the head of the sail. The forces in it is next to nil. It is only there to ensure that the lashing binds or lock itself.

    For the batten parrels I have used a similar, just smaller version. The stopping line there is just a piece of twine, which I stitched to the batten pocket. In other words; those ‘stainless’ hoseclamps have been removed. They had started to rust. The only hoseclamp left, I think, is the one on the boom in front of the topping lifts.

    Good luck!


    (Full size diagram at Arne's sketches, section 7-39)

    Last modified: 21 Feb 2024 08:26 | Anonymous member (Administrator)
  • 20 Feb 2024 14:34
    Reply # 13318070 on 13226713


    I can't believe I finished the sailmaking and assembling today! Another step checked off the list :) After everything was finished, I just stood there for half an hour and stared at the bundle, in total disbelieve what I have created. Amazing feeling.

    I sticked very close to your incredibly helpful documents, Arne. Thank you for all the work you put in them! It took me about 70-80h to sew the sail, which is a bit longer than the numbers Arne estimated for his sails - which comes probably due to me not beeing able to suppres some perfectionistic issues... However, I did change some minor changes:

    • when delivered, the color of the 50 mm webbing was unbearable - very different to the color displayed in the online shop. It happens. That's why I wrapped the hem around the whole webbing, instead of sewing the webbing onto the hem.
    • I guess one sticks to the tools one knows: As I am quite familiar with CAD (and there was no way to get a 5m wooden spline to where I cut the panels), I draw the round edges for the barrel type camber with CAD. I then linearized the curve, so that the deviation between round curve and linearized curve was below 3mm. The rest was diligent work: marking those point on the template. I guess it's just another way to make things more complicated...
    • As I did not have any spare batten tube for fitting the batten loops on the sail, I made cardboard dummies: just wrapped some thin cardboard around the actual battens to get the correct dimensions and fixated them with tesa. Worked as charm.

    In the process, some questions arose:

    • As I understand, the aluminium battens are usually not seawater resistant grade nor painted or sealed or so. At least that is what I used. Any problems with corrosion?
    • Is there a good knot to secure batten parrels and HK parrels to the aluminium battens? I did some tests with the prusik knot: it holds well, as long as loaded. I imagine when the parrels are slack and flogging, the Prusik will losen and slip. Any experience with this? Alternatively I would stick with Arnes way of using hose clamps, but would rather stay with strings only if possible.
    • I find it quite expensive to let the mast head and mast collar be manufactured. Also, the workshops I asked are quite busy and it would take too long. So, I was thinking to build those from grp by myself. It would be very helpful if someone would be so kind to share some working designs. (I've been searching in the knowledge base: the only relevant article I found should be in issue 66 - which is unfortunately not available online...)

    The next steps will be ordering those expensive ball bearing blocks for the halyard, and attaching as many rigging to the sail bundle as possible by now. Then store it away until slip day. And of course, manufacture the mast head and collar.



    PS: The whole sail was sewed by a standard sewing machine: Pfaff Hobbymaster 917. Needle size: 120 or 130 standard universal needles (no needles were broken at all - but some got blunt). Worked okay, not perfect! I got the sewing machine from ebay for almost nothing - if it would have been anything expensive, I wouldn't dare it. 4 Layers of Swela Outgaard are just okay, 6 Layers almost fried the machine - it helped to partly sew inside the roof top at around 0°C... Interestingly, when there was webbing involved it was a lot easier to sew, 6 layers fabric + webbing was no problem at all. Most frightening was 3 layers of webbing + 9 layers of fabric (luckily, only about 10 cm of sewing): It took combined effort of the motor and the hand crank wheel - and the wheel almost cracked of. But it worked.

    11 files
  • 17 Jan 2024 21:04
    Reply # 13302386 on 13226713

    Hi István,

    nice project, thanks for sharing! The Maxi is a good playground, strong and sturdy hull.

    Yep, removing the glue is hell. I tried every solvent at hand, but I found it best to use a "foil eraser". It is basically a rotating eraser, operated with a screwdriver. It just wipes off the glue, without stinking and alike. Maybe you give it a try?

    As I don't like seacocks, the toilet was thrown out, the holes closed and laminated and a dry separating toilet installed. Works like charm!

    Good luck!


  • 17 Jan 2024 19:02
    Reply # 13302319 on 13226713

    Hi Paul!

    It is a nice coincidence, I wouldn't dare to be a pioneer with my Maxi :)

    I bought the boat in October 2022, replaced some small parts, rebuilt the whole electrical system (it hasn't burnt down yet knock-knock), changed some lines; I tore the very old mainsail so had to order a new in the autumn. My rollerfurler genoa is in pretty bad shape too, it should be replaced too, but I wait and see, even if I can't convert the boat this winter, it should last one last season and I convert the boat after season.

    This winter I gutted out the whole cabin just like you, I haven't removed the toilet yet, but I plan to anyway with or without conversion. I scraped off the white-grey linig, it was covered with mold in all the hidden inner curves where it didn't stick to the GRP. Best way I found to remove the lining was a putty knife with it's corners slightly rounded so it didn't tear that badly the lining.

    Removing the glue is easiest (for me) with isopropyl-alcohol brushed over a small area (like two palms) then wire brushing with an accu drill with an ca. 25 mm diameter brush. Larger diameter brushes bit into the GRP, the small one doesn't. I shouldn's say, but wear a proper mask.

    Scraping the lining took maybe 3-4 days, cleaning the glue is taking even more, it's not yet finished. It got cold here too, maybe I ice the project until March.

    I'm rebuilding the two closets too, in an open interior style, up to the inner shell only. Probably I spare the kitchen, it's in better shape, I only change some doors probably.

    7 files
    Last modified: 17 Jan 2024 19:05 | Anonymous member
  • 17 Jan 2024 18:07
    Reply # 13302297 on 13226713

    Quick update on my Maxi 77 conversion:

    mast already delivered. Battens delivered and fitted with bolts and chain. Sail color finally determined. Sail cloth ordered, delivery probably friday. Paper templates already cut out (barrel type camber, direct copy of Ketil's Kelt 8.50). Office stapler ordered. Hull prepared for mast step installation: parts of inner grp shell removed, prepared for Arne-type plywood maststep. Pending workshop offers for partner and masthead.

    It is too cold right now in norther Germany for propper work aboard. Next steps will be chopping off the mast to its designed length (triple-checked the figures...) and sewing the sail. Much welcomed indoor jobs these days.

    Attached are some progress fotos.

    Some hard facts for comparison:

    Mast: Nedal 12m, 177/76x4mm, EN AW 6063/T6

    Battens: EN AW 6060, acc. to Arnes files: boom 50x1,5mm; lower battens: 35x2mm; upper two battens: 50x1,5mm; Yard: 60x5mm doubled up with 35x2mm.

    Sail cloth: Swela Outguard 393 (PES, 190g/mm², PA coated, both sides look the same); 50 mm PES webbing (5t spec); mast batten pockets: Serge Ferrari 705 Precontraint (670g/mm²)

    6 files
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