Mast from a Tree or from metals ?

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  • 06 Mar 2019 22:17
    Reply # 7203169 on 7184461
    Deleted user

    I think we're talking about two different kinds of masts, staved masts are just cut to half the adjoining angle and then edge glued, so an 8 stave mast would have flat edges ripped at 22.5 degrees glued together, I wouldn't even try one of those let alone suggest it to anyone else.

    A birdsmouth mast has a square edge the corner of which fits into a notch cut in the edge of the adjoining stave so they interlock when you assemble them, much less of a hassle.

    I couldn't find that video, been a couple years, if I can find someone to hold the camera I'll post a video of the 20' 10 stave spar I'm putting together tomorrow or the day after.


    Bill F


  • 06 Mar 2019 18:02
    Reply # 7202713 on 7184461
    Anonymous member (Administrator)

    David,
    I haven' tried that, but it sounds quite doable. Gluing back together could then easily be done in a 2- or 3-step operation, thanks to the gap-filling properties and the low pressure needed with epoxy glue. 

    Arne

    Last modified: 06 Mar 2019 18:03 | Anonymous member (Administrator)
  • 06 Mar 2019 15:51
    Reply # 7202420 on 7184461

    Arne, have you ever tried cutting a tree into quarters? It would seem, from the comfort of my armchair, that it would be easier to cut away the unwanted heart wood with a 45˚ power saw cut*, but then a bit harder to glue together again, needing the binding techniques used for staved masts. Anyway, cut into either halves or quarters, the hollowed out tree has much to recommend it.

    * I've done this when making a four-square topmast from milled timber, to provide space for electrical cables.

  • 06 Mar 2019 13:41
    Reply # 7202201 on 7184461
    Anonymous member (Administrator)

    Pole versus staved mast

    I bet building a staved mast is all about having the right combination of tooling and procedures, much like when building barrels. My reason for recommending bigger wooden masts built from a tree trunk, has several arguments for it (.. but that method of course depends of access to a good tree and ability to transport it...):

    ·         It takes moderate amount of tooling and planning to produce a pole mast. Some sort of power saws and electric planes will do to shape the outside.

    ·         With these power tools available, one needs not be a master axe-swinger, so it is doable (solid mast).

    ·         A grown mast will have fewer issues with knots. There will be knots, but they all point in the right direction, so will not produce weak spots.

    ·         Even a dugout, hollow pole mast can be constructed by a dedicated amateur, but it is a challenge. It takes quite some patience and elbow grease to chisel out most of the inside, and then a round-shoed plane to finish the inside.

    ·         By shaping the mast while the tree is raw, it will dry out quicker, without splitting, and the job itself is easier than with dry wood.

    ·         Gluing the two halves together is an easy two-man job, requiring only a few clamps.

    So the pole mast takes more time from start to finish, but probably fewer man-hours of active work  -  and certainly much less brainwork.

    Arne


  • 06 Mar 2019 13:30
    Reply # 7202191 on 7201969
    David Tyler wrote:

    …"Build your first boat for your enemy,
    Build your second boat for your friend,
    Build your third boat for yourself".

    Probably applies to staved masts as well.

    i'll try to build the first mast good enough for myself, as i don't have the right enemies for such a gift – and my friends are usually out with my boat…

    …but – yes, the easy-peasy looking videos often lack some more instructions to understand what makes things work out so smooth.
    my way is to build scale models before going to full size. with some experience i can (mostly) imagine how the difficulties will grow while upscaling…

    ueli

  • 06 Mar 2019 09:01
    Reply # 7201969 on 7184461

    Brings to mind the old saying:

    "Build your first boat for your enemy,
    Build your second boat for your friend,
    Build your third boat for yourself".

    Probably applies to staved masts as well.

  • 06 Mar 2019 05:29
    Reply # 7201823 on 7200427
    Bill F wrote:

    I dunno David, I watched a video where two guys assembled a 8 stave 30' mast in about 9 minutes, they just laid out strips of duct tape sticky side up and put a staple in each end to keep them in place, layed the staves out on the tape and whacked them with a rubber mallet where they crossed the tape, and just rolled them up.


    This all sounds a bit suspiciously easy to me! I very recently needed to apply some window tint to the sunscreens on one of our ferries. The instructions said to peel the backing away from the tint, along with further easy sounding instructions and diagrams. Several of us tried to peel away the backing without success. I then watched a video of how to apply the tint. Well, that looks easy I thought. The tint eventually got applied, but it was not an easy process, and the finish was not crease free the way it worked in the video.  So this and other similar experiences have made me very wary of 'how to' videos which make things look easy. I also had a similar experience making up the tortured ply rudder blades for my new catamaran. Easy-peasy according to the diagrams, photos, and instructions. The resultant blades eventually turned out OK, but it certainly wasn't the simple bang, bang, bang process I was expecting.
    Last modified: 06 Mar 2019 05:32 | Anonymous member
  • 05 Mar 2019 17:15
    Reply # 7200587 on 7184461

    Yes, Bill, but as you said yourself: I haven't tried one yet ...


  • 05 Mar 2019 16:01
    Reply # 7200427 on 7184461
    Deleted user

    I dunno David, I watched a video where two guys assembled a 8 stave 30' mast in about 9 minutes, they just laid out strips of duct tape sticky side up and put a staple in each end to keep them in place, layed the staves out on the tape and whacked them with a rubber mallet where they crossed the tape, and just rolled them up.

    then they readjusted the staves to get them fitting nice and tight, retaped, cut the tape down one joint, and unrolled it again.

    from there it's just a matter of three coats of epoxy wet on wet, roll it back up and  clamp with zip ties, make sure it's straight and true, and then clamp with hose clamps or electricians tape.

    I'll see if I can't find the video.

    The real problem is cutting the staves, you could probably cut the staves for an untapered mast with two guys and a lot of cussing on a tablesaw, but if you want to build a tapered or barrel cut mast you need to use a skillsaw and a bench which can be as simple as sawhorses every 2-4 feet, or even just 2x2s laid on the driveway although I'd want some really good knee pads and some pain medication for my back after I was done :), doesn't even need to be perfectly level end to end although it should be level front to back.

    to cut the birdsmouth clamp the stave on edge between two planks, screw a guide strip down each plank, run your skillsaw down each guide strip, done.
    you can use shims screwed to your bench to position the stave so you cut your taper at the same time you cut the birdsmouth for a straight taper, for a barrel taper you'd have to cut the taper in from both edges of the stave.

    buying top grade timber or aluminium here is crazy expensive, a 16' 1 1/2" by 5 1/2" board of sitka spruce would run you $225 after taxes, about $190 usd, if i pick through the piles I can get a decent boards of western spruce or pine in the same length for $22, I'd probably have to get twice as many if I didn't want any scarfs, but it's still a savings of 80% and I doubt it would take much longer than laminating and then planing down a solid or dugout mast, especially if your ok with an octagonal mast, you could use the modified birdsmouth which doesn't need to be planed down.


    I'm not saying that the hybrid isn't a great way to make a great mast, just that you can make a birdsmouth mast nearly as good for a fraction of the cost and not much more work.

    BillF

  • 05 Mar 2019 08:20
    Reply # 7199951 on 7199729
    Bill wrote:

    Have you looked at birdsmouth masts?  I haven't tried one yet ...
    Bill F

    It's a question of the length, Bill. I've made staved topmasts for hybrids without too much trouble, but I freely admit that building a full length mast would be beyond me. It takes a lot more space, skill, time, and manpower to make and handle long floppy staves, and then glue them together. Practise on a hybrid topmast or a yard first, and then see how you feel about anything longer.
    Last modified: 05 Mar 2019 08:38 | Anonymous member
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