Different boat, but the same process.  The trick is to precoat and sand the areas that will be hard to reach when it is all glued together.  

1.  Coat the inner hull and sand.

2.  Coat and sand the forward and aft sides (endgrain), and bottom of the spacer blocks.

3.  Glue spacer blocks to hull.

4.  Coat and sand the bottom and inside (side that will be glued to spacer blocks) of the inwale.

5.  Glue the inwale to the spacer blocks.

6.  Add the outer rails is not already done

7.  Use a plane and/or belt sander to smooth the top.

8.  Coat and sand the outer side of the inwale (side towards center of boat), top of inwale and spacer blocks, and outer rails.  

9.   Varnish - Should only take you about 523 hours to make it look perfect.  (haha!)

I also installed spacered inwales (broken inwales) during my NE dory build. They look great now but I couldn't get a really clean finish due to little runs of epoxy (later the marine varnish) emanating from close to the innumerable blocks of wood. Wish I hadn't bothered installing them since they seem to serve no other purpose than to induce swearing! OK. OK. I exaggerate, but not by much! 

Broken inwales are aesthetically pleasing but you do suffer for your art!

The drips can be avoided by taping polyethylene sheeting to the inside of the boat to catch the drips. Alternatively, you can just use tape without the sheeting. You'll still get drips on the inside of the boat, but they'll be where it's easier to sand them instead of right up against the blocks. Use 2" wide plastic packing tape.

You'll always need one more clamp, no matter how many you have.

Laszlo

I recently added lash points to my finished dory. They are modeled after scuppered inwales.
Gang processed a board like this…

Rounded everything over with a 1/8 radius router bit.

Cut the main blanks apart and tapered the ends like so…

Drove screws into the pointy ends and epoxied and varnished while spinning them on a jig slapped together from scrap…

Finally split the working blanks apart on the table saw, after pulling the screws of course. Nice fresh untouched wood for the gluing.

Insalling on a finished boat...

Glued in with thickened epoxy with graphite added to protect for UV damage, no varnish required.

This way all the epoxy and varnish work takes place off the boat so no drips to deal with. Maybe something like this would work for you?

I made this tool to help with precision varnish removal...

More pics here, including the mid level tiedowns which were made the traditional way. The drips, sags and runs made me think of a better way! For me, and a finished boat at least.

https://www.flickr.com/photos/feetwetphotos/albums

Click thumbnails to see captions...

Cheers,

e

I installed spacered gunwales on my Skerry before it was a kit option.  I also cut a rabbit joint on the outer gunwale strip to hide the raw edge of the plywood.  I did not coat the gunwales with epoxy!  I did however put about five coats of spar varnish on them.  I don't see any reason to epoxy the gunwales or the breast hooks.  It seems like a waste of epoxy and time to do so.  My spacer blocks have concave ends for a more pleasing appearance.  This is a simple operation done on the drill press with a simple jig.  Check out the link to a few pictures:

https://photos.app.goo.gl/un9b1p1Yvjb5BJqY7   

   Wow that's an awesome idea for hiding the plywood edge, looks fantastic 

   I'm fascinated by the idea these dont even require epoxy. I've seen boats at the center for wooden boats that use just varnish but I've also stripped boats that looked awful after years of sun to do paint. Does the epoxy help the wood hold up and look nicer longer? What purpose does it serve on a part that doesn't need strength?

The epoxy keeps the water out of the wood. Among other things, that makes the varnish last longer because it's on a dimensionally stable surface - the wood doesn't swell and contract as much as without the epoxy. That keeps the varnish from cracking and peeling.

Laszlo

If you coat your gunwales with epoxy you will need to cover the epoxy with a protective coating that protects the epoxy from ultra violet exposure.  Epoxy does not do well when exposed to UV rays.  Varnish will last "about" two years of exposure to the weather with or with out an epoxy base.  If your boat is kept inside, when not in use, varnish will last indefinitely.

Here is what the experts say: "If you plan to use epoxy prior to applying varnish, be thorough. If the application is poor, moisture will find its way into the wood and the moisture barrier qualities of epoxy will work against you, increasing the chance of rot and of premature failure of the coatings. If everything is done right and water is kept out of the wood, coating wood trim with epoxy prior to applying varnish works extremely well."

My personal opinion is skip the epoxy on the gunwales of your small boat, varnish alone will be satisfactory. 

If you have a boat with yards and yards of bright work, by all means put three coats of WEST SYSTEM 105 Resin/207 Special Clear Hardener before you varnish.

Jackie

 This question is for Jackie Marliespike. Jackie I viewed your photos attached to your post on 5/14, great looking work by the way. It dosen't look like you doulbed up on the outwale, am I seeing this correctly? It appears to me that you used 1 piece of stock for the outwale.

Phil,

Yes I used a single piece of mahogany for the outer gunwale.  I did cut a rabbit joint on the outer gunwale strip to hide the raw edge of the plywood.

This is visible in the first picture.  I didn't like the clunky look of the, extra thick, original gunwales.  By using the inner strip and spacer blocks and the rabbited outer strip I think you get a gunwale that is strong, but also does not look clunky.

When you use a rabbit joint on the outer gunwale you will have to install the breast hooks higher by the thickness of the rabbit joint,  This is not difficult, but you just have to be aware of this adjustment.  

There is not any thing wrong with the original gunwale design, I just cannot build something with out introducing a few changes that personalizes the finished product.

Here is a link to all of the pictures of my Skerry build:

https://goo.gl/photos/Tnj5DKaWcUv19ZCr6

JM

 Jackie,

That's exactly what I was thinking. That's a lot of lumber hanging on that 6mm plank. Eliminating that second piece of Mahogany really gives it a clean look. Unfortunetly I don't have the tools to cut the rabbitt joint which really makes that gunwale look really clean.  I may stain the top edge of the sheer to give it a contrasting color stripe. Thanks for taking the time to answer my question.