roll of 17lt deck radius

I have an old set of plans for the 17LT, and they do not explicitly describe the way the deck radius should be planed on the sheer clamps.  They only indicate that both cockpit and fore deck beams should be of 16" radius.

Given the shape of the bulkheads, I assume that between the cockpit deck beam and the aft bulkhead; i.e. over the length of the cockpit, the deck radius needs to roll from 16" to whatever the aft bulkhead's radius is.  But that's only a space of 32".

Do I have this right?

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RE: roll of 17lt deck radius

Oh, and while I'm asking... is the radius behind the cockpit 24"?

RE: roll of 17lt deck radius

It's called a rolling bevel.  The bevel of the shear clamps should roll smoothly from the area near the deck beam to the rear bulkhead.  The top of the rear bulkhead is the curve the rear deck should take.  When you build, make a bevel guide using the top of deck beam (should be the same radius as the forward bulkhead's top) plus the thickness of your deck planking.  And make a similar guide using the rear bulkead's top curve plus planking thickness.

 Happy building

RE: roll of 17lt deck radius

I built a 17LT earlier this year and am referring to the construction manual as I type.   There is a table on page 110 which gives the aft deck radius FOR THE LT as 49" - the standard (non-LT) version is shown as being 24".   I don't understand the numerically massive difference, but I built it OK!

In both cases fore deck radius is shown as 16".

Adding, if I may, to ootdb's reply - when you cut the ply to the above radii for the front and aft bulkheads you will be left with 2 x pieces of scrap ply, each with a concave curve in it (the matching convex curved piece becomes the top surface of the respective bulkhead of course).   Simply take this (trim it up as necessary to make it easy to handle), mark the centre of the curve or arc, and - holding this piece vertically across the hull - move it back and forward along the  sheerclamps, keeping the marked c/ line directly above the centre-line of the hull.   The angle between the curved piece of ply (the 'former', or template, or planing guide) and the sheer clamp at each point along the hull is the angle you need to plane to - in effect, in cross-section you'll be taking off a small wedge of wood that gradually changes angle as you move along the hull.

If worst comes to worst, I believe that CLC supplies planing guides in its kits, so maybe you could purchase these from CLC.

This was my first-ever build - I found it quite straightforward, but you do need to securely hold down the hull or butt an end up against something solid or it will move away from you with the fairly strenuous planing you'll be doing!

Finally, don't worry about getting it micron-perfect - the thickened epoxy takes care of a reasonable gap once the deck is secured down.

Finally finally, if I've misinterpreted your question and am guilty of showing you how to suck eggs - sorry!

Enjoy the build.


RE: roll of 17lt deck radius

My apologies - brain burp in my earlier response!  You don't need to add planking thickness to the curves.  Ugh.

Wordsmith's notion about using the leftover ply from your bulkhead cutouts is good, just extend the curves a bit to allow you to cover the entire width of your hull.  And remember to roll your hull upside down right after you are finished fastening your deck.  That way any thickened epoxy squeeze-out (should be some all the way around) will flow back into the joint instead of down your hull sides.  That is also a good way to see where you might want to spread some squeeze-out to starved areas.  Then take a break and relax.  That's a big step.  After an hour or so, go back and clean up any drips or runs that are still on the hull.  Means less sanding later.

 Good luck.

RE: roll of 17lt deck radius

I just went out and prepared to make a template for a 24" radius (the wood I cut my bulkheads from is long gone - this project has dragged on for years, hence the old plans), but when I compared it with the curve of the aft bulkhead in the blueprints I could see 24" wasn't even close.

What a relief to hear 49" is the correct radius.  I'm glad I checked back here.  Thanks so much for the info.  Sticking point averted.

I will have the sheer clamps planed at least by the end of the weekend.  Scarfing that little bit to the front section of the deck is going to slow me down though.

Another question: my blueprints show the deck sections cut diagonally from a sheet of plywood, but wouldn't that look weird having the grain run diagonally?

RE: roll of 17lt deck radius

Glad we cleared that up, Nostick!  To answer your second query first - I too wondered about the alignment of the deck grain when laying and cutting as suggested, but trust me, it didn't end up with a strange looking 'diagonal' grain pattern.   Do not ask me how or why, it just works that way!

Regarding the scarf joint at the bow - unless you are a deft scarfer, don't bother.   My suggestion is to lay down the fore-deck ply, ensuring that the edge for the bow-piece to butt onto is square across the hull, not slanted.   Once the epoxy is cured, cut a short length of ply about 1" wide to fit between the sheer clamps at this location: mark a centre-line along its length (it will only be 5" or 6" in length): and simply epoxy this along and under the front edge of the deck up to the marked line, giving you about a half-inch 'sill' on which to glue the bow-tip.   Use a couple of light clamps to hold the strip while the epoxy cures.

Cut out the triangle of ply for the bow-tip, a bit oversize, and simply drop it onto the epoxied 'sill' and epoxied sheer clamps at the bow.   If you have cut the sheer clamps off short, simply glue a couple of narrow strips of ply vertically inside the bow, level with the top of the hull sides, to extend the sheer clamps and to give you something meaty to glue the bow-tip onto.

Wait for epoxy to cure: trim with plane: and sand.

I think you'll find this will allow you to have a very fine joint line there, at this very visible part of the hull which - for some reason - everyone seems to look hard at, and stroke!



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