Maxi 77 junk rig conversion

  • 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
  • 17 Jan 2024 17:38
    Reply # 13302279 on 13226713

    Hi István,

    welcome! What an nice coincidence that the two of us are tackling a Maxi 77 conversion just about the same time. Will be good for learning from comparison!

    My two cents about Nedal: When I contacted them and described my needs, they pointed their reseller in my homecountry directly to me, which I think is a very good service. Only, it took 3 weeks. Might be the same for your case, so keep your hopes high if you don't get an immediate response from them.

    What do mean by the glued inner liner? The white/grey linoleum on the walls? The inner grp shell of the hull? Of these two options, I'm afraid I already removed parts of both... ups.

    You mentioned your cabin refit. May I ask what you are changing? Probably we are in a pretty similar situation, as I also stripped out almost everything.


    Cheers,

    Paul



  • 17 Jan 2024 13:34
    Reply # 13302111 on 13226713

    Dear Jan! 

    Thank you very much for your help! I can't be that blind that I couldn't see the contacts, but here I am... :D Maybe I was tired when browsing.

    First I wait for the price offer for the Nedal pole, maybe I get lucky, and wait for my PJR book to be delivered. Also I'm in the very middle of a cabin refit, and it would be practical to finish it along with the conversion - I try to convince my wife that this is logical ;)

    Stay safe! 

  • 16 Jan 2024 22:29
    Reply # 13301939 on 13226713

    Hello Istvan !

    Here are their (Rosa) addresses:

    https://rosa.pl/en/contact

    You must roll down, then press any "V" sign on the right side (drop-down list ) ;)

    take care ! Vigyázz magadra !

    Jan

    EDIT:

    My junk guru Kris Matuszewski used aluminum power poles bought somewhere in Poland. Kris should be arriving in Lanzarote soon, so if you would like to contact him, he may be available on Facebook for some time.

    Last modified: 17 Jan 2024 11:59 | Anonymous member
  • 16 Jan 2024 16:17
    Reply # 13301703 on 13301177
    Anonymous wrote:


    Hello István,

    welcome to the JRA!

    My advice is to contact Nedal. Just click on "Lighting columns" and select Hungary:

    https://www.nedal.com/contact/sales/

    Frank

    Dear Frank!

    I've contacted them for a price offer through an Austrian distributor, they seemed heplful, we'll see the price.

    Until that: what density and type sailcloth do you recommend? For now I'm leaning towards sewing a flat cut sail myself (I've sewn a few for my self built small boats). Maybe Paul mentioned that he had sailed with a junk rigged boat with a way too heavy sail and it had zero windward performance. What I liked working with and has a friendy price tag is a 380 g/m^2 polyesther cloth with PU coating on one side, I don1t know if it's appropriate for a sail like this.

    On the other hand we have predominantly light winds in the summer on Lake Balaton, Hungary, so I'm still browsing info about cambered sails, and if I can sew one myself, or I should contact the sailmaker I know.

  • 15 Jan 2024 15:21
    Reply # 13301177 on 13301116
    Anonymous wrote:

    Hello everyone,

    Anyway, it's just all dreaming until I can find good mast material. I definetely want aluminium, what I probably can source in Hungary are made by Polish company, Rosa (rosa.pl), but I can't find their email adress. Maybe I could reach them via their Hungarian dealers, if it worth the hassle.


    Hello István,

    welcome to the JRA!

    My advice is to contact Nedal. Just click on "Lighting columns" and select Hungary:

    https://www.nedal.com/contact/sales/

    Frank

  • 15 Jan 2024 11:39
    Reply # 13301116 on 13226713

    Hello everyone, hello Paul!

    I'm new to the JRA, but after reading some of Roger Taylor's books, watching YT videos and reading the availabe material on this site, I got really interested in converting my boat, which is also Maxi 77, hull number 1619, into junk rig. I read this whole thread and found interesting information, I actually thought that installing a free standing mast requires more reinforcements.

    Anyway, it's just all dreaming until I can find good mast material. I definetely want aluminium, what I probably can source in Hungary are made by Polish company, Rosa (rosa.pl), but I can't find their email adress. Maybe I could reach them via their Hungarian dealers, if it worth the hassle.

    https://rosa.pl/produkt/sal-115m-p

    This is a two-part pole, ordering a raw upper part would only be 9888 mm according to their bluerint. IF they are willing to ship a raw upper part at all.

    https://rosa.pl/produkt/mal-12-5

    This one is a bit overkill according to the previous posts, but I don't mind extra safety, althought moving it on the ground would be a real challenge for two people.

    What do you suggest? Does it worth trying to reach out for the company?

    PS: Paul, whatever you do, don't start scraping out the glued inner liner!

  • 06 Dec 2023 20:25
    Reply # 13287931 on 13226713

    A quick note on Aluminum alloys and their strength. It appears that Nedal, for example, uses "at least" values while some of the sources I gave use "typical" values. At least that seems to line up well with this wiki article. I would guess some of these differences have to with where in the world the metal is alloyed and how accurate the the process controlled. Suppliers who control their own source may feel confident using values they can achieve, while importers would have to use the "at least" value.

  • 26 Nov 2023 22:42
    Reply # 13283653 on 13283624
    Anonymous wrote:Gulf of Triest this Sommer,  18 Kn gusting 24, little steep waves 0.4 m. I started conservatively to avoid too much stress on her 40 years hold spar. With 4 panels up we were making poor progress upwind. I wondered if the boat was under canvassed so I raised the 5th and the 6th panel. The boat heeled to 15 degrees, stiffened up and started to go upwind properly. The mast bended at any gust.

    I think every boat has a heel angle that tells when canvas is maxed out. Mine is at about 10 degrees, the previous owner says the boat he owned before this one was happy at 15 degrees. So it sounds like you were probably canvased correctly. With my boat, 10 degrees will get me up to hull speed, so no need to add canvas but my boat is probably heavier and stiffer.

    My alloy mast is a folding one. The dimensions are 10 cm diameter at the base and 6 cm the top. The joint between the

    ...

    measures 10 cm at the base and 6 cm at the top. Hasler itself developed the rig of the KF 20+ and sailed his own KF 20+ "Pilmer" upwind in F6-7 "in steep breaking sea" (see article below) without breaking the rig. Surprisingly, according to PJR the mast for a Kingfisher 20+ with a 21 sqm sail should measure 20cm at the base!

    I think that is what a lot of people are getting at, the PJR is well over built. I think part of the difference is wood vs. aluminum. Well, that is not quite right, woods strength as quite well known but wood is in general, no uniform for any one kind of wood. It depends on where it is grown, how it is dried, how or if it is glued together, where the knots are, etc. PJR does most of it's calculations based on wood with, I would imagine, extra strength built in to compensate for wood flaws. (or maybe extra strength just because it is someone else's boat and they feel responsible for it)

    I wonder how "alarmingly" is really a thin bending mast on a coastal cruising boat...

    :)   That is why I have been quoting that word, 'cause I don't know.

    A thin mast would mean less parasitic drag on the starboard tack and less sail distortion on the port tack (am I right?) and while bending it could absorb gusts smoothly.

    As with anyone, I want as little windage as I can get but a broken mast has no windage at all.

    Could be a thin mast made of carbon fibre a good solution for a coastal cruising boat? 

    I trust my carbon fibre skills as somewhat less trustworthy than my wood butchery skills  :P

    Aluminum, with no welding or other fastenings, gives me something that is the least likely for me to mess up.

    P.S 2:  sorry for parasitizing this thread again :)
    I think by now we have T-shirts for that.
  • 26 Nov 2023 20:39
    Reply # 13283624 on 13226713

    My little experience about mast bending on my KF 20+:

    Gulf of Triest this Sommer,  18 Kn gusting 24, little steep waves 0.4 m. I started conservatively to avoid too much stress on her 40 years hold spar. With 4 panels up we were making poor progress upwind. I wondered if the boat was undercanvassed so I raised the 5th and the 6th panel. The boat heeled to 15 degrees, stiffened up and started to go upwind properly. The mast bended at any gust. My alloy mast is a folding one. The dimensions are 10 cm diameter at the base and 6 cm the top. The joint between the upper part and the lower one is covered by a sliding alloy tube. The lower part of the mast is quite stiff while the upper part bends. I have a second original mast in one piece which measures 10 cm at the base and 6 cm at the top. Hasler itself developed the rig of the KF 20+ and sailed his own KF 20+ "Pilmer" upwind in F6-7 "in steep breaking sea" (see article below) without breaking the rig. Surprisingly, according to PJR the mast for a Kingfisher 20+ with a 21 sqm sail should measure 20cm at the base!

    I wonder how "alarmingly" is really a thin bending mast on a costal cruising boat...

    A thin mast would mean less parasitic drag on the starboard tack and less sail distortion on the port tack (am I right?) and while bending it could absorb gusts smoothly.

    Could be a thin mast made of carbon fibre a good solution for a costal cruising boat? 

    Ciao

    Mauro

    P.S: I see now that in the picture below the mast of Pilmer seems to bend backwards :)

    P.S 2:  sorry for parasitizing this tread again :)

    2 files
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