Gunwales Spindrift N10

[Glen M]

Well I guess I'm going to dive in.

MY N10 prints came in the other day and after going over

them I noticed that it states to laminate 3 sections

together for the gunwales,

"to keep them from springing out of shape".

I wanted to use solid wood strips 1 x 2's with

a 3/8" x 3/4" round groove pre-cut down the center,

and this glued on. Then screw a length of flexable .742"

OD poly-ethel pipe into the groove for the rub rail.

Will I still have a "springing" problem with this type of

set up, or can I pre - steam bend the wood into

shape before I glue it on, and get this to work.

[rlchenry]

I think you should really laminate the three strips. Even if you could bend a single piece, I don't think it would be as strong as a laminated one.

Why not cut the groove after the gunwale is glued on? Yes, it would be harder to manage with a router.

Alternatively, you could cut a groove only in the outer-most laminate piece (provided the thicknesses are right) and glue it onto the others. There's no reason you couldn't have a gunwale that was 1.5" wide (I don't think).

[Brent]

The gunwales on my Spindrift 10 (not N) are pine 1 x 2s. Starting at the bow I clamped these into place overnight before epoxying into place. This gave some time for the shape to settle in. Got a smooth fair curve.

I plan to screw on a 3/8 mahogony or oak rub strip after the boat is painted.

[Designer]

Glen,

You are better off laminating the gunwales on a nesting version. Imagine if you bend a 1x2 and then cut it in halves, you will then have two straight pieces. Two laminations will have some springback when cut, you are better off to use three laminations so that you will have a fair sheer after the boat is cut in two (don't forget the gunwales have to support the sides as they will want to flatten also, after they are cut). Laminated gunwales are a bit stronger as any short grain or defects will only be in one lamination. The gunwales are the only support that the top of an undecked boat has.

If you are building a one piece boat you can put the gunwales on without laminating.

[Howard]

When the plans say to laminate both sides at the same time (no mean feat for one person)....I presume this means to do one 1/4" lamination on one side...tack it at the bow and stern....then do the other side....then back to the first side...tack it...then the other...and so on. When all three are in place...you put all the clamps on? When dry you plane it down so that the tops and bottoms of the gunnels are horizontal and parallel to the water?

Mahogany will be hard for me to find around here, but I think I already have some walnut and ash. Would you use the walnut in place of the mahagony?

If so...I might wind up using walnut for all the laminations. I may make the daggerboard and rudder from a lamination instead of plywood.

Howard

[Designer]

I like to bend both gunwales around the boat at the same time but only glue one side. If you put on only one gunwale (especially one piece) you will force the boat out of shape. No problem, when I put on the other gunwale it will force the boat back to the true shape, right? WRONG. When the first gunwale is glued on, it makes the boat much stiffer and therefore the second gunwale cannot force the boat back to true shape.

Before I put on the gunwales I like to fit the breasthook and the transom stiffener, this gives me something to fasten the gunwales to.

First I prepare the gunwales. After ripping the laminations to the same size I saw a bevel on the bottom edge to the correct angle, typically 8 - 17 degrees ( I don't care for the bottom edge to angle down).

I dry fit the gunwales first by drilling a pilot hole through the forward end being careful to line up the bottom edges of the three pieces and putting a screw through the three pieces into the breast hook with the gunwales a bit higher than the sides (I like to taper the ends of the gunwales about 1/8" to prevent the ends from looking heavy). The aft end of the gunwale is angled out resting on a chair or any convenient prop.

After the second side is screwed at the bow you can start clamping the gunwales to the boat working toward the stern alternating from side to side. I then drill a pilot hole and screw the aft end into the transom stiffener with the gunwale raised slightly like the bow.

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Remove one side and the back end of the other side, butter up the first side with epoxy, screw the bow end through the old hole for perfect alignment and start clamping, carefully aligning the bottom edges. Pull both sides around working to the stern. After glue is dry remove clamps and glue the other side.

The screws are important because they allow you to get perfect alignment when the three pieces are slipery with glue, save clamps because you never have enough and they put the pressure just where you want them. You only need to use enough clamps on the unglued side to hold it roughly in place, maybe one or two.

Dont worry about the laminations stepping up with the bottom bevel, you can easily plane the top edge after the glue is dry, it is more important to align the bottom edge because it is harder to clean up later.

Aesthetically the gunwales are one most important parts of the boat so put in some effort to make them fair. If the sheer has a hump in it, adjust it when you clamp on the gunwales to that they run in a sweet fair line.

As mentioned above, I like to taper the ends by about 1/8" and the top edge should follow the camber of the transom and carry that angle all the way to the bow, another nice touch is to let the breasthook stand up 1/8" at its aft end and plane in some camber to match the bevel that you plane into the top edge of the gunwales.

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[Brent]

Howard, laminating together alternating strips of walnut and ash will make a strong and very beautiful rudder.

[Designer]

The species of wood for the gunwales depends on whether you are going to use fendering, paint or varnish. I have seen lots of rotted out gunwales caused by the fender keeping the wood wet or water getting through all of those fasteners into the wood.

If I am going to put on a fender I prefer to use treated pine that is thoroughly dry. On the Spindrift that I take to shows I used western red cedar for the first two laminations for its light weight and colour and ash for the outside lamination for it's hard wearing qualities. Even though it is very heavy there isn't much of it. Ash does not seem to be very durable if it stays wet and it will go black if you don't keep up the varnish.

If you are going to paint the gunwales then any reasonably straight grained medium density wood will do.

If it is going to be a working yacht tender and spends a lot of it's life outdoors I prefer to have no varnish.

If the boat will be covered when not being used then you can get very creative, I like your walnut/ash combination.

[Howard]

Thanks for the information. Every word of it helps. Graham's post on how to install the gunnels cleared up a lot!

I found a 3' long piece of treated pine....an old 2" x 12" that is clear and tight grained....that has been in my basement for 14 years. It should be dry by now....so that covers most of my blocks and interior bracing pieces.

I need to look in my Dad's barn again. Once upon a time there was a stack of 12' or longer 1" x 6" cypress. I might be able to find enough of that to do gunnels. But now that I know the parameters....I'll find something that will work.

Also, I found my WS manuals, and for clear coating wood, they clearly say to roll on thin coats of epoxy, then tip it with a piece of cut up roller.... something I have not been doing. I've just tipped it with a small brush, and that just moves the bubbles around...or makes more.

So if I ask about 50 more questions....you folks will eventually get this thing built for me!

Howard

[Glen M]

Thanks for all the great advice from everyone.

This forum was the determining factor for me to get

this brand of boat.

Thanks.

I'm pretty sure that this will not be my last question.