Wooden mast building

Discussion in 'Sailboats' started by Gaffers, Dec 30, 2009.

  1. Gaffers
    Joined: Nov 2009
    Posts: 7
    Likes: 1, Points: 0, Legacy Rep: 19
    Location: Farnborough

    Gaffers Junior Member

    Having recently built a nice little dinghy from boatplans.dk I took it on the water this summer. I was very pleased with most aspects and quite proud that I had build the entire boat including mast and sails.

    I am still not 100% happy with the mast though. I currently have a 1" wodden mast but I am not convinced it is strong enough to withstand strong winds.

    So I am looking to rebuild and keep the wooden effect. I also want to hide the halyards etc inside the mast. My thoughts currently centre around 8 or 10mm x 60 or 70mm planks laminated 3 or 4 thick with adjoining circular grooves routed out to 8-9mm (the halyards are 6mm) and fitting grooved plastic wheels in the turns. I was going to epoxy the insides of the grooves to waterproof them but I am concerned that the rope will wear the epoxy away quite quickly.

    Has anyone tried this? What about putting metal jackets inside the grooves to stop the rubbing?

    Thanks in advance!
     
  2. bistros

    bistros Previous Member

    See:

    Building a hollow mast. There are lots of sites on the web about this.

    --
    Bill
     
  3. apex1

    apex1 Guest

    A little layer of glass fabric in the second epoxy coating (out of three) will make for enough abrasion resistance and is easier to achieve!

    Regards
    Richard
     
  4. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 494, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    No, putting grooves in your mast will effectively make it considerably weaker. Don't even think about it.

    Internal halyards and lifts are a common technique and a worthwhile endeavor, but they go inside the mast, literally.

    The birdsmouth building method is good one, though that site offers has some common errors. Use Frank's site (the one listed above) as a guide only and a general overview of the method, but have the mast worked out by someone with some experience.

    Did you build the 11' Dinghy-Vee? If so, the boat is so small that a hollow mast seems a lot more trouble then it's worth.
     
  5. Gaffers
    Joined: Nov 2009
    Posts: 7
    Likes: 1, Points: 0, Legacy Rep: 19
    Location: Farnborough

    Gaffers Junior Member

    Yes I did build the dinghy vee, although I have made a few modifications and I have plans for a few more which will make it more suited to dinghy cruising.

    It is small and I have a small gaff rig on it but as they say 'good enough for government work!'. I also intend to sail this boat long distances so a nice strong mast will work wonders ;)

    I like the birds mouth idea posted above, thats a very handy link. I will have no problem putting a v groove in the edge like that but tapering all the sections uniformally will prob have to be done for me as I lack the tools.
     
  6. alan white
    Joined: Mar 2007
    Posts: 3,731
    Likes: 122, Points: 0, Legacy Rep: 1404
    Location: maine

    alan white Senior Member

    The hollow mast is a bit overkill, but so what if you don't count your time. Internal halyards make no sense though. Yeah, you could do it, but it's not generally done on very small boats. Too much miniaturization and complexity for little if any return in performance. Even rope to wire halyards are too much to deal with on a small boat. Go with Spectra for small diameter external halyards and put your money and time into something else.
     
  7. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 494, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Agreed, internal halyards on this boat is not necessary and adds unwanted complexity. Ditto the need for a birdsmouth on this particular boat. Did you change the rig to gaff or do you use the sprit rig designed for the boat? I disagree on the spectra line though. I wouldn't put much into the running rig, other then a good quality double braid.
     
  8. Perm Stress
    Joined: Sep 2009
    Posts: 554
    Likes: 24, Points: 0, Legacy Rep: 323
    Location: Lithuania

    Perm Stress Senior Member

    Hollow mast this small is too miniature. By the way, hollow mast tend to rot from inside at some point in time. It should be remembered, that no coating or paint is 100% water proof, except carefully welded sheet metal :)
    I have seen piles of discarded hollow wooden masts in my local yacht club, most of them more bad inside than outside.
    As to diameter, there exist some old rules of thumb.
    The one I remember is 21mm of diameter for 1m of length for gaff rigged masts.
    Good luck with your mast project!
     
    1 person likes this.
  9. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 494, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Perm Stress, I'm sorry your yacht club doesn't know how to care for it's wooden masts, but they all don't rot out from the inside eventually. I currently own a 50 year old hollow mast that's just fine. Of course it's been cared for, obviously better then your sailing club cares for theirs.

    Properly encapsulated birdsmouth or box section masts, of good design and reasonable care, will last many generations. For all practical purposes, these encapsulated surfaces are waterproof, not water resistant as you've suggested. This is born out with repeated testing and long term (decades) in service trials.
     
  10. dskira

    dskira Previous Member

    I take pass my masts with petroleum gelly.
    But they are solid.
    Happy new years everybody
    Daniel
     
  11. Luckless
    Joined: Mar 2009
    Posts: 158
    Likes: 7, Points: 18, Legacy Rep: 105
    Location: PEI, Canada

    Luckless Senior Member

    If you have time, would you care to post just how you care for your mast? I'm in the process of researching various topics for my future boat, and I have a goal of hand crafting (or building a robot to do the work. I am a geek after all) as many parts as I can.
     
  12. hoytedow
    Joined: Sep 2009
    Posts: 5,857
    Likes: 399, Points: 93, Legacy Rep: 2489
    Location: Control Group

    hoytedow Carbon Based Life Form

    A small hollow mast is easy to make if you don't need it to be round. Use 1" by 2" fore and aft and 1" by 3" port and starboard sections. Paint the insides with wood preservative before assembly, preferably a cuprous solution. You may incorporate halyard pulleys into the design for the internal lines running. Rout the outsides with radiused corners and finish to suit yourself. You may even fiberglass the outside for additional strength. Spruce or cedar should be strong enough for a small boat. Easy, at least not too difficult.
     
  13. BeauVrolyk
    Joined: Apr 2009
    Posts: 160
    Likes: 10, Points: 0, Legacy Rep: 153
    Location: San Francisco, CA

    BeauVrolyk Sailor

    Gaffer,

    As much as I adore bird's mouth spars, you probably don't want to do it just to allow you to more your halyards internal. There are loads of problems once you "open" up the inside of a spar. Specifically, it will get wet in there and there's really no way to dry it adequately. So, unless you're really going to soak all the wood in epoxy, you'll get rot. Further, when I go long distance sailing, I always take the internal halyards OUT of the mast so I can watch them and insure they aren't chaffing. Internal halyards are great for racing boats, and I have them on my boat for that reason, but they really do decrease the reliability of the rig in multiple ways.

    Happy New Year,

    Beau
     
    1 person likes this.
  14. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 494, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I don't have issue with internal halyards, they have their own maintenance issues, like everything else. Hollow masts have to be protected internally and have all the needs that wooden boats have to resist rot, mold, condensation, drainage, ventilation, proper support, etc.
     

  15. apex1

    apex1 Guest

    There was a boatbuilder in Hamburg Finkenwerder in the late 1890ies he made masts out of wooden segments instead of solid forest. Fishermen found out that they could catch a bit more wind in the topsails behind the dikes with lighter masts and taller rigs.(Hamburg is about 100km from the North sea)

    The masts were hollow and the halyards inside. The oldest original one I am aware of is the main of "Johanna" 1908, Ewer, built in steel on steel frames.

    I doubt there was much of Epoxy or other contemporary stuff involved. But clear enough, some craftsmans knowledge.

    Regards
    Richard
    ps: I do┬┤nt know much about sailing craft, but a hell of a lot about craftsmanship!
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.