A Visual History
The Building of Aslan
Making the Splash Coamings
Updated 08/26/00
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I started with the starboard side coaming, laying the phillipine mahogany stock on the deck and marking the curve of the cockpit seat back on it from underneath.  Then, I marked another parallel line about 3/4" from that line to form the width.  Setting my band saw table at 20 degrees, I cut the first layer out so that the sides angled up and outboard, matching the incline of the cabin bulkhead.  Then, the second layer was made by laying the stock on top of the first layer, and marking it, and repeating the process until I had all 6 layers to roughly the length I wanted.
The second through 6th layers are temporarily screwed together.  A belt and random orbital sander smooth out the curves, assisted by hand sanding.  Then, a curve is drawn on the coaming, on the inboard side, so I can cut it into the shape seen here.  The band saw is valuable for this operation, and I suspect it would be much harder with just a jig saw. 
This top view was intended to show the compound flare the coaming has, but it really doesn't show it.  A small coaming will extend all the way around the cockpit, just 3/4" high (which is the size of the end of this coaming.)  Once I was satisfied with the coaming on the starboard side, it was time to duplicate it for the port side.  Making one was fun enough, but making two alike worried me.
I unscrewed each layer, and traced them out on posterboard.  Then, I cut out each layer's pattern, flipped it upside down and traced around it on the phillipine mahogany stock.  This gave me a tracing in mirror image.  With my band saw table still at 20 degrees, I cut these out, making sure they would angle outboard.
Next, I had to duplicate my free-hand curve drawn on the starboard coaming.  Placing them as shown in the photo, I simply guided a pencil along the top edge of the starboard coaming, keeping it as level as possible, and drawing its profile on the port coaming.  Its hard to see in this photo, but the top on the starboard coaming is angled down toward the deck for most of the length, until about 1" from where it attaches to the cabin side.  This is mainly for looks, but also helps water on top of the coaming to shed outside of the cockpit.  At first I wondered how to make this complex angle, but found that by setting the band saw table at 90 degrees, and feeding the coaming through the blade, I could get a great graceful angle by relying on the coaming's 20 degree angle outboard.
You can barely see the line drawn on the inside of the port coaming on the right in the picture.  Feeding it through the band saw on the outside of the blade, rather than inside like I did for the starboard coaming, kept the angle of the top cut so it will shed water outside of the cockpit.

The coamings were then disassembled and the first layer was glued to the deck using stainless screws and epoxy thickened with maple wood flour.  Maple wood flour is a very fine, ground up sawdust sold as a thickener for epoxy.  Even though maple is a light colored wood, when mixed with epoxy it makes a paste that is mahogany colored, making it perfect for gluing these laminations together.  Then, the second layer was glued to the first, putting counter-sunk screws down into the first layer.  Each subsequent layer was added in this way, then a plastic scraper was used to remove the squeeze-out between layers.  Paper towels and white vinegar removed the excess epoxy (vinegar will remove uncured epoxy.)  They are now ready for sanding and finishing with red mahogany stain and 5 or 6 coats of marine varnish.

Added 8/26/00
This photo is a little dark, but it shows the splash coaming installed and stained.  You can also see the 3/4" splash coaming extension running all the way back to the stern.
OK, so where are my mistakes?  You know I made some.  There are several screw holes in the starboard splash coaming that will have to be plugged.  I have a "plug maker" bit that will cut out face grain plugs that are nearly invisible when put in (with the grain running the same way!)  So that's not a biggie.  I also started out with the wrong angle on the sides of the layers, 25 degrees, matching the back of the cockpit seats instead of the angle of the cockpit bulkhead/companionway.   I quickly found out that the angle of the bulkhead was critical to make the coaming line up along it as you see in the second picture (the side view.)  So I recut that angle on the band saw.  So this one was pretty easy once I got started.


 
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