The Cockpit Gets a Coaming

Standoff for coaming

Cockpits need coamings.

What is a coaming? Simply stated a coaming is a vertical surface whose purpose is to prevent or help prevent the egress of water.  Hatches have coamings and so do cockpits.We had this idea that what would look really cool and would be really practical at night is to use LED rope lighting along the underside edge of coaming to provide a glowing courtesy light on the cockpit floor.  So, to do this we started with a 5/8" x 1-3/4" strip of yellow pine that is epoxied in place around the deck edge.  You can see it in the first photo posted. The mahogany coaming itself will overhang this by 1-1/4".  This creates a 5/8" x 1-1/4" slot under the coaming for the LED rope light.  We'll wire it through the pilothouse wall to a rocker switch.
We choose mahogany to add a little elegance to this social area.  The stock was planed to 5/8" to help take the slight curve of the cockpit.  It flexed just fine and was carefully measured for length and using a bevel gauge, we angled the side to rear joint which was 99 degrees. Basically just had to set the saw to 9 degrees and cut carefully.  Make it slightly long and creep up on it.  Once in place, the long sweep from 6" to 3" was sprung from a batten and cut with the circular saw.  The corresponding bottom cut was marked using a compass setting of 3" held along a pencil line marked along the deck's edge.
Again, we buttered it up with epoxy glue mix and used countersunk screws to be bunged over before coating the entire coaming in epoxy.

Notice the shadow on the coaming as it stands proud of the cockpit walls. At night, soft light will flood down from that groove.

The rear coaming board was installed in much the same manner.  Cut to length, 9 degree bevel. Sneak up on the final cut.  Glue and screw.  I also glued the vertical joint and put one screw at the top to pull it tight.  It will disappear when bunged and sanded final.

Now the cap and back to the wood shop to make it...

cutting the miter with a Shark saw
and using a wood block guide to
keep the blade vertical

The miter joint photo shows the cap.  It is almost too heavy to slip over the walls and bend to the curve of the walls, as well as, make the curve horizontally.  I'll go ahead and explain the dimensions.  It was milled 3/4" thick by 1-3/4" wide.  A groove was dado-ed 11/16" wide for a little slop for the epoxy to hide and all edges rounded over with a 1/4" round-over bit.
I will advise that two steps are taken before "horsing" it into place for fitting and please fit all pieces before gluing.  One, slightly round over or bevel the top edges of the coaming walls to help slip the cap over; and two, put a C-clamp across the edge of the coaming.  You can see in the photos of the glue up what I am talking about.  It is really easy to snap off the wood adjacent to the dado as it is twisted sideways.

Fitting the starboard cap, note the C Clamp insurance.

The first miter is determined by marking the inner corner and outer corner of the vertical coaming on the underside of the cap.  One could also use a bevel gauge to mark this.  Either method gets the intersection of this odd angle marked.

The back cap is placed over the top cap and marked and cut.

With everything fitted final, we mixed a bag of glue, loaded the Wilton cake decorator bag and laid a generous bead in the groove as the clamping, pushing, coaxing and cussing finally persuaded the caps into place.  Lots of clean up on the squeeze out and wipe down with denatured alcohol.

Wrapping in Dacron...

Gonna try this method and see how it goes...

Screw holes filled and sanded.  Ready for cloth.

Progress has slowed a little.  We have had a Frozen birthday party for Miss Addy's namesake and farm themed one for her sister a month later here at the house. Along with that went the prerequisite cleaning, painting and general work to make the place presentable.  In the interim my father's kitchen was remodeled by all of us splitting duties and we consumed time tiling, painting and such.  This is not to mention the mandatory tractor rides that we try to squeeze in daily for my grand baby and by the time I make it home from a twelve hour round trip day, there is not much left of it for building.  It's all good stuff and when my daughter and girls head back up to Ohio in December to be with their husband and Daddy (who is stationed there in the CG), we are going to miss them bad and this house will be a little too quiet...

On to the build...

As of this posting date, we have moved a lot quicker and hope to spray the exterior paint before cold weather sets in and we're fighting cold spots in the shop.  Actually the timing may be perfect for the water based LPU as it hates hot and dry, prefers cold and wet for flow out.

Pilot house wrapped and stapled around inside edges of openings.

The procedure is pretty easy, especially with the Xynole cloth.  The "Try this method" part of the title referenced the use of staples to stretch and hang the cloth. The procedure is to stretch it out with as few seams as possible in the layout of the cloth, staple with stainless or Monel staples to hold in place and pour copious amounts of epoxy resin as this cloth drinks it.  The cloth actually swells around the staples so it makes it easy to fill the weave and staples. I chose to wrap the inside of window openings for added protection to the plywood edges.
I am unconcerned with the seams or joints between plywood panels. They will be faired with a filler mix and once all of the "flats" are finished, we will fillet the junctions or joints where structures tie together at ninety degree angles.  I have to remind myself that the Xynole is a "covering".  It provides little structural (tensile) strength as wood glass but it is much more flexible in the event of an impact.  Primarily it is there to provide an enhanced waterproof layer of protection and to prevent the surface checking that is common in Marine Fir plywood as it ages.

Wet out cloth cloth with protective paper to limit mess.

One trick that worked well to help with the wet out was to actually jack up one side of the boat so that there is a slight angle to what would have been a plumb, vertical surface and the epoxy resin can be poured down the side and moved around with a plastic squeegee.  Remember to take your time and let the resin do its thing.  Once it has, squeegee with increasing pressure to bond the cloth firmly to the plywood.  One step that isn't necessary with the Xynole as opposed to fiberglass is to squeegee and wipe excess resin from the cloth's surface to prevent pooling and potential floating of the cloth.  The Xynole just simply continues to drink it in and when we make our final hard squeegee pass, the cloth is tight and dry but not starved (white patches).

The pilot house is wet out after a round of filling and sanding.  Note the little pneumatic
T-50 stapler sitting in the engine well... $30 Freeman ordered from Home Depot, works great.
White decks are un-wetted Xynole stretched and stapled.

Next to cover were the decks which are to be left un-glazed for a non-skid surface. These weren't done first because we were trying to limit any epoxy pooling that would fill the weave and mess up the texture from the vertical walls. Glazing is a term I first read in Ruel parker's Sharpie book and it  simply means spreading a thickened layer of filler on the very open Xynole weave to fill and smooth it in one fell swoop.  The decks will all get a glazed border and fillet where needed.  This should create an appealing smooth grid with non skid panel fills.

Half of deck wet out.  Xynole overlaps all edges.

Half of front deck wet out.  Deck was one continuous piece split down the middle on the
front deck and rear deck to limit junctions.

Engine well panels stapled in place and ready for wet out.

The glazing was done using plastic and spring steel squeegees or body filler spreaders.  I have also used steel drywall trowels.  The trick is to put a good deal of pressure and work it back as thin as possible.  The joints will be rough but a belt sander will take this down.  Two rounds of this will be necessary to completely fill the weave.

Engine well glazed. Pilot house wall is partially glazed. 

Rough joint filled on first pass.

One other part of this application process that needs mentioning concerns sanding.  On what you see of this process so far, we did not sand the wetted cloth before glazing.  My fear was that I would be cutting into the cloth.  On the cockpit liner (ceiling) I did sand the cloth to eliminate the extremely rough nibs and fibers. I have to say it made for less final sanding and less glazing filler on application.  It was noticeably smoother to fill and was easier to get a thin weave filling only coat.  Careful though, it is really easy to sand into the weave... a careful balance.  The jury is still out on which method is best.
One other thing to keep in mind is the use of Fumed Silica in the mix.  I used a U S Composite's fairing filler mix that is an obvious mixture of phenolic microballoons and silica.  The problem with FS is that it can be hell to sand.  It gets rock hard, BUT, it is essential if you are going to keep the glaze vertical and not drooping.  I had to add a little more FS to the USC fairing mixture to use its thixotropic properties to keep it in place where corners or edges had to be built up. A good rule of thumb for the filler to start with is 2 parts microballoons and one part silica start.  The resin to filler ratio is two to 1 filler to resin by volume.  If I mix a 12oz batch of resin, I will mix this into a bucket of filler containing 24 oz by volume of the filler mix.  It is a starting point and will seem too dry to start but keep mixing and you may have to add more fumed silica to get it to that peanut butter consistency you want, and, by the way, that's good old fashioned Jiff consistency, not these runny organic versions that you pour on a sandwich instead of spread.

Well, we cannot move any further along until I do a little more construction.  The cockpit coaming is next and then we finish the joints as we push toward paint.

Pilot House Roof...

You will notice portholes are in.  The fence to the right is gone now and in its place a 16' gate.

Miss Addy sees the light of day... at least for a little while.
I lead off this post with a picture of Miss Addy pulled out of the shop so we can finally get some idea of what she looks like. I think we are all pretty much in agreement that she has taken shape as hoped.

Bo likes it (or is he just hungry?)

The picture shows a finished roof on the pilothouse and this post will cover what it took to get it there.
The first step was getting it out of the shop.  We at first tried a Warn Power Puller winch, no good.  It bogged then shut down repeatedly.  We then resorted to the tractor which did great and had wished we just tried it before.  We bolted in a couple of heavy duty D's and used large yellow straps to pull it.  Once out it was time to start framing the ceiling.

First layer going in...

The ceiling at this point was comprised of one layer of 3/8" bead ply epoxied and screwed to the walls of the PH (I'm going to abbreviate this from now on).  As was the case with the cabin roof, I wanted recessed pocket lights, as well as, wire chases for the air conditioner, anchor light, horn and search light.  We also wanted a little insulation up there so the roof wasn't so apt to turn into a radiator.
What was decided is a frame grid of 1" x 2" pine (and wider in places to support handrail) and an infill with two 3/4" layers of polystyrene foam sheet.  Instead of epoxy this time and because we were basically putting in a frame on 2' centers, we used a generous amount of PL Premium adhesive and screws.  All layers screwed and glued together.  The first layer was attached and allowed to setup overnight so that I could route and hole saw recesses without gumming up the bits with soft glue.

Recessed holes for 2W LED pocket lights and access holes for
future equipment (to be covered with small plates).

Brackets were fabricated from 8/4 Mahogany with a hand drawn sweep that looked pleasing to my eye. The top was beveled to match the roof and were screwed and epoxied in place.

Now that this was accomplished we used a router with a  3/4" mortising bit and played "connect-the-dots".  This was to receive 3/4" PEX tubing which has a larger OD than the foams thickness so we had to route the bottom of the second layer of foam as well as the next layer of 3/4"x2" pine battens.

Now for the pipe.  It was simply mashed into place and took a little squeeze from a pair of pliers to get it into the wood on the batten crossings.

This left us with the 1/4" covering skin of Marine AB fir.  Clamped, marked and glued in place it was pretty straightforward.

Screwed and glued into place, it was time for the Xynole fabric and epoxy.  Wet out was much easier than the hull as temps were in the upper 90's.  Just worked quick, poured and slowly dragged it around with squeegees.  This was after the normal screw hole and seam fill using an epoxy and microballoon fairing mix.

All surfaces were flush planed and sanded and the edge rounded over slightly so that the fabric would roll over without creating a wear point.

The roof was primed and painted without a full weave-fill like the sides will see.  We wanted that "painted canvas" look. the last coat was rolled on.  Spraying just wasn't building it fast enough. One note and this can be seen if you zoom into the roof at the AC opening is where we had to deal with a fabric edge seam.  I fought this on the hull and knew that the best tack here would be to treat it as something that cannot be convincingly hid by careful matching.  What was done instead was to lay two pieces of Frogtape about and inch apart, centered on the seam.  Then, using a filler mix, we squeegeed' an overlapping fill from the AC opening to the edge and down to the end of the fabric.  Immediately pulling the  tape off each side left a thin, clean line that would make you think it was somehow seamed professionally.

That was it.  the roof is complete and using a few nailed-together 2"x6"x16's as a pusher, we shoved the boat back in her house for now as we move on to glassing and painting the outside final.

Deck Install and a big ol hole...

12' wide gap in the building.  Next comes a ramp to pull
the boat out on using skids (yet to be constructed).

Installing the Deck...
(and BTW, I cut a hole in my shop)

As you can see I have a large hole in the side of my boat shop.  I'm not sure why I bring this up now, but its always worth noting when you cut away a large chunk of any structure.  I knew it wouldn't be too long before we were ready to open this up to work on the roof and, well, the reciprocating saw was just sitting there so down she went.

Cardboard pattern laid out for final marking and transferring to 1/2" AB Fir Ply

So, here's how I did it..
Again, hot glue gun and cardboard.  It really doesn't take too much explanation so I'll gloss over some of what you see in this series of photos and let the captions do the rest of the talking. The procedure was to glue together enough cardboard to cover what the limits of a 4' x 8' sheet of ply will do.  I made sure that I landed on a frame with my joints and simply marked under the ply with a pencil or Sharpie marker, flipped it and traced it out.  To my surprise the pattern for the rear deck could be flipped along the centerline and used for both the Port and Starboard.



Port side shown upside down to be undercoated with epoxy before installing.

Heavy ribbon of glue.  Probably 12oz of epoxy plus silica and 4 tablespoons of milled fiber
till its as thick as peanut butter.  Not that greasy organic crap, thick like good old Jif!

Look at the glue.  We used a lot of epoxy mixed with milled fiber and fumed silica to seal and bond the deck. Again, get those Wilton cake decorator bags that come in a tear away 50 pack from Walmart.  Works great.  Use a tall tea glass to stand it up or have a helper hold it open after you roll it down a few inches and grab the stir stick full of goo, raking it off through the bag.  Or just have your cake decorator show you how its done.  I will recommend that you snip a small hole in the tip to allow air out the bottom as you load it.  You won't loose much.

Roughed in pattern. Note that I have left the excised exterior wall
rest where she fell.  I am bad about this sort of thing.

The curved deck around the cabin will take a little scribing for a close fit.  The first picture shows rough fit cardboard with hot glued butt blocks.  The second picture shows the scribing of the cabin wall.



Deck is in and needs to be trimmed flush with the hull.  Planer was the tool of choice and
worked pretty quick.  Belt sander got it close and following the hull angle.  Transom gets flushed down to the rear
deck later.  Lots of 1-5/8" SS screws. Get an impact driver if you don't have one.

Solid pine breasthook let in and planed to curve of deck.

Ply deck installed over breasthook.

Sheer Strake

Stagger the boards back the distance you want the scarf.  The
strake will be 4" or so wide so the scarf is 8" long.

The sheerstrake is the trim board along the hull's edge that the sheer cap will attach to and will serve as the furthest outboard edge of the hull.  This is generally not what will hit a dock or submerged object first so it doesn't have to be solid rubber.  Bumpers should be deployed when docking.
To build these we need to join our 12' stock together to give us around 25 total feet of  1" x 5" once we split the 1" x 10" rough sawn stock.  We are using pine again, very dense and resinous. We join through the use of a long glue joint at a very low angle.  The power planer does a good job of hogging a lot of wood using some general guidelines.  It is pretty straightforward as you just step the stock back and let the planer run across the board's edges as it slowly creates flats.

You can see the layout guidelines penciled in and the formation of the scarf joint.

Final joint should be close enough for epoxy to work it's magic.  Remember that a little gap here works wonders with epoxy, it is actually preferable to a super tight joint.

You have an idea of the total length.  It eats up all of the shop, plus a little.  The joints are glued up using black poly plastic pieces to protect the backer blocks. The board was split then planed to 3/4".  Do this after the glue up so that the planer takes out any inconsistency in the scarf joint and they will look perfect.




































Installing them (get your clamps ready and maybe a car jack)

Prep the hull. We used epoxy to glue this in and so need to peel off the paint so we can get a good bond to the underlying glass. It was really just the last step in flushing the edge of the deck and holding the belt sander at waist height and sighting down along the hull, was pretty easy to get a good flush edge.  If there were gaps, the epoxy would fill those in as we faired the deck joints.

The final photos don't say much about what it took to get these suckers in.  We started in the middle, gluing our way back about six feet each way as we neared the ends.  That is where it got tough. We used a combination of clamps, jacks and brute force to follow that sweeping sheer. It was tough but the results are worth it.  The sheer strake really accentuates the sweep of the hull that gives this hull such grace for a hard chined vessel.

Sweep shows elegantly...

Nice joint.  Hard to tell but the epoxy is clear and filling what looks to be a dip along the face.

The final step to finish this out is to plane and sand the sheer strake flush with the deck.  Then a round over bit so that the Xynole fabric can round the deck and tuck neatly behind a future sheer cap.

Circling back to the hole in the wall...

It was time to make this thing mobile and I'll end this post with this project.  We need to finish the roof and there is no room.  The only way is to skid it out past the wall. 
So two things needed to be done: 1) build skids and get the old cradle out from under the boat and 2) build a ramp to get the boat out 16 or so feet. 
The skids were cut to fit the rocker from doubled up 2" x 12"s nailed together and carpeted on top.  I also used some old 1/4" cutting board material HDPE from a leather cut table and heated the bends on the bottom and nailed them in place.  We jacked up the boat and slid them under without a hitch. 

Just a pretty simple deck to skid out on.  I'll use the tractor to do it.