Thursday, 18 February 2016

Coamings construction

I had a bit of momentum up again, so continued work in the cockpit construction zone on the coamings.   Two posts in a month, this blog is out of control.....

I had neglected to cut the openings from the cabin into the space under the seats so attacked that first. Anyone following after me, cut the holes BEFORE you attach the side decks and supports unless you are a contortionist.  Getting a jigsaw all the way around was impossible, some jigsaw work, some hand saw, some cursing......

Below is looking from the cabin in under the starboard side.  The cuts are level, the beam underneath on the inside and the seats all slope towards the hull which is on the left:

Below shows the cover partially constructed, I wanted to be able to close off the cabin from dust before continuing.  I will not be opening these too often, so have gone for a simple system of slotted braces top and bottom to hold them in place.  There will also be a strap/bungy similar to the ones on all the other internal storage doors.

And from the cockpit side.

Below is a profile of the latches.  The longer top piece is positioned with enough space between the packing and top of the cover that you can slide it up until you can slide in the bottom piece.  Then the whole cover slides down with the bottom locking onto the cabin rear, with enough over at the top to stop it sliding into the cabin.

Then it was back to the coamings.  I spent quite a while trying to visualise what I wanted and consulting the plans.  The coaming drawing has a detail but the overall shape and style is left for the builder.  Mr Whipple on the original went for a stylish sweeping curved one that met the rear deck near the quarter deck:


I wanted more of a straighter outside edge closer to the angle of the cabin side which I had also made straight sided.  Using the seat back as a guide I positioned a brace on the rear of the cabin (below right) with a 10 degree down slope and decided how far aft and out I was going to go.  Below shows the braces in place, the outside one has an angle planed/sanded on to match the cabin side all the way aft.

Using the seat back I had also constructed a solid wood rear piece to set the angle for the outside piece (below on the left of the picture).  Note the upper 40mm x 20mm pine brace epoxied and screwed into place.  The upper coaming surface will slope down towards the transom, I was going to make it level but I felt it was just too high.

Looking from the outside rough cut.

Because I had kept the outside surface straight it made the internal storage much smaller, but I still cut access holes as it will come in handy for winch handles, spray jackets, or anything else.

And from the inside, I also put a couple of vertical braces in for extra support under where the winch will go.

Looking down from overhead, note the second end cap down aft to cover the end grain of the ply which comes out 10mm for a nice fillet of epoxy down the track:

I must have got carried away and didn't take more photos, but the final piece in the puzzle was the top cap.  I cut it from 20mm thick pine, leaving a 10mm overhang on the outside and a wider piece in the middle as a support for a hardwood winch pad.  The inside edge is flush with the seat top.  This is looking on the port side to aft, at this stage the outside, seat back and top are dry fit.  Some components are epoxied on such as the bracing pieces on each:

From the aft quarter, in addition to the end cap I cut a curve on the aft end of the seat back down to meet the quarter deck and made a 20mm wooden doubler to strengthen it.  At this stage I am thinking stainless steel pullpit rails in line with the coaming end to the transom and up onto the quarter deck.

A close up of the aft doubler and end cap, all dry fit and to be epoxy filleted to the deck, each other and to the bottom of the coaming cap.

And an inside shot:

I was thinking about the storage cut outs being open to rain/birds etc and decided to use the pieces I cut out to make covers similar in style to the underseat access.  Below shows the inside lip on one end to rest against, the other end has an overlap inside to stop it coming out again:

And them sitting in place.  The outside dress pieces prevent them falling in, they will have bungy straps fitted to the covers and a securing point in between them.

The port side had taken me several days due to figuring out exactly what I wanted to do.  The starboard side was twice as quick because I knew the angles and measurements from the first one. They were surprisingly close to the same, slight difference in length but not easily seen.  Below is the starboard side bottom braces being epoxied in place and screw holes filled.  Once dry each side had the inside edges rounded off, then the whole lot got a good coat of epoxy over everything:

I didn't take any more photos, same as the other side.  Below is the final look without the storage covers on.  Both hardwood winch supports are just sitting there for the shot, and each coaming comes apart into three pieces.  Looks like a nice, deep cockpit to hide in:

After a bit of dreaming, I pulled it all apart to prep for assembly.  The insides of the seat backs/coamings and the outside pieces had been epoxied already, so the seat backs got a coat of oil based undercoat/sealer.

The underside of the coaming got two thick coats of epoxy wet on wet, with a single coat on two of the storage covers as well.  The other piece on the left is having the upper screw holes filled in preparation for a coat of fibreglass pre assembly.

The last piece of current activity was a coat of primer/sealer under the seats.  All the area had previously been epoxy sealed, note drainage holes so I hopefully will know if there is water in this area:

Before I assemble I will fibreglass the outside surfaces of the outside bits, put a couple of coats of exterior paint on the inside surfaces, epoxy the other storage pieces and then stick it all together.

But that will be another post, there is a bit of work there!


  1. What a great find this blog is. Great dedication now going into your fourth year on her, so over a couple of nights I've read the whole thing inspiring stuff. I did wonder how you managed to find the time but you answered that one a few pages ago shift work! So that's a bonus of doing that type work I guess. Any idea what it's cost so far? Or would you not like to say as it's worth whatever it is for the journey. One thing that got me over the last few posts is the appearance of a fan in the cockpit I totally forgot you were on the other side of the world in summer! You would need a heater here in the UK ! Keep up the postings looking forward to the finished boat.
    Not sure you have seen this another dedicated chap . Thanks for sharing .

  2. Glad you enjoyed it. Having the build 20-30m away also makes it easy to do little tasks as you go. Slip out for an hour and epoxy something, clamp it and walk away. The fan has definitely been needed in the last few weeks, cooler (relative I know) weather is a few months away yet.