Preview: How to Build a Caledonia Yawl, Part 18 – Scoring a Waterline with a Laser Level

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Striking and the scoring an accurate waterline is an easy job with a laser level and a good set of plans.  Join Maynard Bray and Eric Blake as they walk us through the steps.

NOTE: After filling screw holes and fairing scarfs and booboos and sanding the exterior we rolled on and tipped out two coat of UNthickened epoxy. Sorry it wasn’t documented, as we did it late one night with no extra clean hands for the camera. Use the yellow foam roller covers supplied by your epoxy source — anything else will dissolve. Tip with a disposable bristle brush. You should be able to start the second coat upon finishing the first coat if you work your way around the boat. Good to have a helper, one to roll and one to tip, and keep the epoxy fresh in smaller batches so it doesn’t get sticky.

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16 Responses So Far to “How to Build a Caledonia Yawl, Part 18 – Scoring a Waterline with a Laser Level

  • Avatar

    William Gehring says:

    I finished building a CY several years ago and it lived on a trailer. Nest year it will be at a dock, (fresh water) so bottom paint seems in order. Side to side leveling of the overturned boat seems easy. What about fore and aft? Mark the DWL on both stems and then level the boat using a laser level? Also, it seems I could build a less robust and simpler frame to set the boat on, am I correct? Thanks.

    • Avatar

      Geoff Kerr says:

      It will certainly be easier to mark, mask and paint if you turn the hull upside down. Three or four spry bodies and some tires as fenders should make quick work of that. I wouldn’t spend a lot of time or money on a frame…two stout sawhorses, or some handy cribbing( wooden blocks, etc.) should do just fine. Collect an assortment of shims and wedges and, whatever the status of the ground you are working on, you should be able to level on both axes. I do mark the dwl on the stems, referring to the plans and measuring down from the intersection of the sheer and the stem.

      I regularly use a rotating beacon laser level from my local rental center…the type used for interior work on ceilings and floor framing, and exterior work for grading and foundations. The unit with a tripod runs around $40/day. Once the boat is turned over and up on supports expect the leveling and marking to take a couple of hours. You’ll have to reposition at least once, maybe more depending on your space. Even with the high tech device anticipate having your mind bent as the WL crosses plank laps, and be prepared to make adult decisions and adjustments…keep track of the overall picture, and have fun.

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        William Gehring says:

        Thanks for the quick and spot on reply. A somewhat unrelated question: Are mooring covers practical for a CY, masts up, at the dock? Saw Ned Ludd a few years ago with a nice travel cover. Who made it? Thanks again.

        • Avatar

          Geoff Kerr says:

          I’m reluctant to leave my masts up for very long at a mooring or dock, certainly not for periods where I’d want the cover on. Unstayed masts work at the steps and partners and the wear just isn’t necessary. The spars are so quick to set and strike that is just seems better to stow them.
          A cover can certainly be used at the dock or mooring. Ned Ludds’ cover uses the main mast, set in crutches, as a ridge pole, with snaps under the rails. It was built by Cloth-n-Canvas in Colchester, VT. I can tell you that they have made many cover for me and do fabulous work, but must warn you that you will need to take your boat to them for fitting, and that you will need to book well( months!) in advance.

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    Stephen Weld says:

    Some folks (and some boats) want sheer and rake in their paint WL. I guess you’d use the laser plane as a reference and work with a full length batten. No obvious good way to deal with laps. Comments?

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      Eric Blake says:

      Hey Stephen check out the Caledonia y’all build series that we did a few years back Geoff Kerr address is this towards the end of that series. Best, Eric

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      Geoff Kerr says:

      There is a very specific way to deal with the laps, and it will bend your mind as you concentrate on projecting the intersection of the plane of the WL around each of those corners. I don’t have a handy reference or illustration available, and pledge to look for one. Look at the video Eric refers to for help. Basically there is a little zig back toward the middle of the boat as the line crosses each lap. There is a WoodenBoat magazine article in the index somewhere that discusses and illustrates sprung waterlines…esp. on larger vessels. I’d suggest sticking to the DWL ’til you know differently.

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    John Simlett says:

    Just finishing the build of my lobster boat …I was thinking of cutting in a waterline and thought I’d come in here and ask the question (as usual :) ).

    Brilliant video, and on the strength of it I’ve invested in a laser leveller. cost me £45 (US$ 56). Obviously it won’t be as sophisticated as the one you used…. but if it does the job, I’ll post the details on here .

    Thanks a lot guys – worth every second of your time!

    • Avatar

      Geoff Kerr says:

      You can find the waterline on the drawings. The profile construction drawing is particularly useful here. I usually measure along the keel from a station/mold, and mark both stems with a punch so I can’t inadvertently sand it off or paint over it. To confirm you can measure up from the building frame baseline, but that is a bit more intricate.

  • Steve Stone

    Steve Stone says:

    Hey All ~ A few of you have started Part 19 and asked about the epoxy coating that went on the outside of the hull before Geoff turned it over. Yes, it’s two coats of West System epoxy, UNthickened, that we rolled on late one night (without a camera). Geoff said two coats, and that if ya don’t lollygag you can do the second coat right after you finish the first coat, so that’s what we did.

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    Thomas Fulton says:

    Would an old fashioned water level, a bucket of water with a long syphon tube that is marked at your stem reference point, work to lay out the waterline?

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    Harry Hammond says:

    A fine tutorial: these videos are just great. Hats off to Eric for such a thorough narrative, on the fly, too!

    Even though a full-featured laser unit can be rented for not much dough, inexpensive* 16″ or longer bubble levels with a laser pointer embedded can also serve. If a few moments are taken to make or shim up a level platform, one can point the level in any direction to project a level line. I leveled stem and stern marks on my 23′ build this way, and of course, marked the waterline. Lots of ways to skin many cats…

    *Amazon offers a Clearline unit <$23

  • Avatar

    Geoff Kerr says:

    A hearty thank you to Eric and Maynard for leading us through that adventure. I’ll offer a few thoughts of my own: The laser level is indespensible at my shop too, but I don’t own one. For the two or three times a year I need one I run to the local rental center and plunk down $35 for an afternoon rental of a $900 unit, complete with adjustable tripod. I’m usually done in an hour. Eric’s use of the “tall” batten is a trick I’ve never seen, and I am thrilled to add it to my bag. Working alone I usually use a ruler to strike short sections and trust the masking tape to fair things up. Finally, for the novices amongst us, let me reemphasize Eric’s comments about the joggle at each lap. It will hurt your brain to try and understand them, but you must honor them as you mark, scribe, tape and paint. Any attempt to fudge them will look awful and we will mock you mercilessly as you sail by us! Carry on…

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