Building a CLC Northeaster Dory -- "Free at last! Free at last! Thank God Almighty, we are free at last!"

Over the course of the past few days, as I have completed the Susan Lee, I have made some unusual -- even controversial -- decisions about the best way to apply varnish. I make no pretense to expertise, but even so I will conclude with a few comments about the rationale for the process I used.

Some Speculations about Applying Varnish

Several days of warm winter weather brought daily high temperatures just warm enough for applying varnish after using some incandescent shop lights beneath the boat to warm the hull. In part because of the brevity of this warm spell, I decided to apply each of my final finish coats "hot" -- i.e., before the smell of the drying paint had fully dissipated.

Most experts insist that you must sand between coats to give the varnish some "tooth" that it can latch onto. The premise seems to be that a smooth gloss finish gives the new coat of paint too little to grip. Sanding is used to create a three-dimensional surface to which the fresh varnish can attach itself. And this implies that the bond itself is a mechanical one instead of a chemical one.

Frankly, I'm skeptical by nature and I'm especially skeptical of this reasoning. If the roughness of the surface is essential, then it should be preferable to sand with rough sandpaper instead of smooth sandpaper -- 110 or 220 grit, instead of 320 or 400. Yet none of the experts makes such a distinction. None of them discourages sanding with 400 grit, yet such a fine sandpaper scarcely roughens a fully dry surface at all.

After much reflection, I have concluded that the bond between coats of paint is probably chemical rather than mechanical. I believe the reason for sanding dry paint before re-coating it is to remove some of the thin, hard, oxidized surface layer. Whenever I have wet-sanded between fully dry coats, I have noticed the strong smell of varnish in the rag with which I wiped the boat down -- and perhaps even some smell of varnish from the boat itself. Furthermore, anyone who has sanded off a blob of varnish knows that the surface of the blob can be very hard while the inside remains soft (and smelly) for weeks, months, or years. I think the same thing is at work in sanding between "fully dry" coats. Once the oxidized surface is removed, the solvents in the new paint can mix with the solvents now exposed in the older layer, and chemical bonding can take place.

Now consider a thin coat of high-gloss varnish. I can get six coats out of just a quart of varnish (and I must keep each coat thin to avoid drips). Most of the volume of that paint as it is applied is actually solvents that evaporate fairly rapidly. So, once dry, the layer of paint is very thin indeed. Thus, if I were to sand between coats, I would be quite likely to remove most (or all) of the varnish I just applied. But if the paint is not entirely dry between thin coats (i.e., it is still off-gassing the solvents), then the new paint will have a chance to form a chemical bond with the old, and sanding should be unnecessary. This is especially true if one "refreshes" the solvents by wiping down the hull with denatured alcohol just before applying the new varnish.

Only time will tell if I am correct in these speculations. But it is my boat, and the worst that can happen is that I have to sand it down and start over. I'll update this blog if my varnish starts to flake off in the next six months or so.

(Update 10/8/16) Having subjected the boat to an entire season of use, I am pleased to report that the varnish has held up extremely well. There are, of course, a few scratches and dings, but the boat may not even need a touch-up for next spring.

(Update 12/11/2019) I lightly sanded and re-varnished the interior last spring -- in part because I wanted to switch from a matte finish to high gloss. The exterior of the hull is still in very good condition after four seasons of use. No problems with the coats of varnish adhering to each other.

A Safe Method for Turning the Boat

Early in the building process, the Northeaster Dory is light enough for two reasonably strong men to lift and turn easily, but as the boat accumulates fiberglass, hardware, and paint, it becomes somewhat heavier. Ultimately I decided to use a rope harness to lift and turn the boat.

Here is a picture that shows the system in overview:

The red rope is 1/2" rescue line capable of lifting thousands of pounds. Obviously one does not need rope that strong, but it is what I had on hand. Any 3/8" line should work equally well. I threw an end over a beam in the garage and tied a bowline, with the working end danging down to support the boat.

A loop of 1/4" black line is created from a three or four foot chunk of line using double fishermen's bends. Here is a nice web page about tying that knot:

Double Fishermen's Bend

This loop of line is connected to the 3/8" working line with a Prussik.

The two loops of white line can be any strong webbing made into a loop with an overhand follow through bend (or water knot). Alternatively, one can use a double wrap of 1/4" line or a single wrap of 3/8" line. Again, that line is made into a loop using double fishermen's bends. As you can see from the close-ups, I used D-rings to connect the white lifting loop to the black Prussik loop.

It's still a two-man job to raise and turn the boat, but it doesn't take much strength and there is virtually no risk of dropping the boat. To raise it, one person lifts one end of the boat while the other (from a step stool) slides the Prussik up as high as possible. The same procedure is used to lift the other end. Once the boat is suspended from the D-rings, the sawhorses are moved out of the way, and the boat can be easily turned as the white rope slides through the D-rings. One should keep a good grip on the hull so that it doesn't spin too fast or too far.

Lowering the boat just reverses the process. Once person lifts the boat to remove the weight from the Prussik. The other person reaches up, gently loosens the Prussik, and slides the knot down to the desired position.

That's all there is to lifting and lowering the hull.

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After months of challenging and interesting work and one final flipping of the hull, I now have a beautiful and complete Chesapeake Light Craft Northeaster Dory. With an ever-so-slightly regretful sigh of relief, I now bring this construction journal to --

THE END

They call it a "tombstone transom"!
. . . A fitting terminal image 

Building a Chesapeake Light Craft Northeaster Dory -- Sanding and Varnishing . . . repeat, repeat, repeat!

The dory after five coats of varnish

After putting the second coat of high-gloss Interlux Schooner Varnish 96 on my dory, I wasn't entirely satisfied. The paint went on too thick in places so that I had some little runs; in other places it was too thin and left "holidays." The only cure for those problems was a thorough wet sanding. I generally used 320 or 400 grit sandpaper for this and did not notice much difference between the two. For the bigger drips I'd drop down to 220 for the first pass. (I'm trying to be quite specific about my problems and procedure so that others my learn from my struggles and so that I myself will be reminded in a few years when it is time to refinish the boat.) To handle the drips, I used a block while sanding to try to achieve a flat surface. Elsewhere I just pushed the sandpaper with my fingertips in an effort to roughen up the shiny little golf-ball dimples. Since I did not want to sand through the underlying coats of varnish, I did not try to get the entire hull perfectly smooth and uniformly gray.

After sanding, I mopped the boat out thoroughly with a damp dish towel and then wiped it down again with a clean cotton rag moistened with denatured alcohol. I let my can of varnish warm in the sun for a few hours, hoping that would allow me to apply a very thin, smooth coat. . . . And it worked! The third coat of varnish was good enough that I seriously considered calling the job done. The finish was very glossy with only a few drips and holidays. But a high gloss finish does reveal imperfections by making them gleam. And more to the point I was a bit concerned about the thickness of the protective coat. How much varnish had I taken off during all that sanding? The varnish is there to provide a sacrificial layer of paint and block UV light from harming the fiberglass. If it looks nice, that's just a fringe benefit. I decided that a fourth coat (this time of Interlux Goldspar Satin Polyurethane Varnish 60) would add to the boat's beauty and durability. And I decided that I could apply this coat “hot” -- i.e., without sanding the previous coat of varnish since it was still wet enough to perfume the garage with the scent of paint. I did, however, wipe it all down very carefully with denatured alcohol to insure a clean surface and to soften the varnish and assist in bonding.

Alas! I should have stopped at three . . . as is avowed by many a binge drinker waking up with a hangover! One thing I immediately learned is that Interlux Satin Varnish is an entirely different beast than high-gloss Interlux Schooner Varnish. I had learned that I could apply the Schooner Varnish in an exceedingly thin coat and achieve full coverage without drips. With one quart of that varnish I now know that I could give the interior of the dory six coats of paint (if I were doing it again). In contrast, the satin varnish is much thicker. I doubt I could get three coats from one quart. I fumbled and stumbled during my first application, slopping it on so thick in some places that it subsequently dripped, and yet my brush went dry so quickly that I left other places bare. I won't say it was a disaster, but I was sharply disappointed to have gone from a  a lovely third-coat finish to an ugly fourth.

The only remedy was to let the paint dry for two days, sand out the drips, and try again. During that time, I reviewed some YouTube videos about applying varnish. I particularly recommend the technique of dabbing the paint in vertical bars before spreading it with firm brush strokes. Here are a pair of links:

https://www.youtube.com/watch?v=5Bk7Tb0Zi48&index=5&list=WL
https://www.youtube.com/watch?v=NWI_0vrDh0s&index=6&list=WL

(I have been using a foam brush instead of a bristle brush, but my technique is the same.)

For the fifth coat (which I was determined would be the last), I recruited Sue to help me. The satin varnish seems to begin drying even more quickly than the high gloss so Sue's job was to follow along right behind me, craning her neck in every direction so that the light on the wet paint could reveal drips and holidays before it was too late to deal with them. Ultimately, the fifth coat went on reasonably well. I can imagine it being better, but I pronounced it, “Job done!”

That brought up the next task: flipping the boat over and preparing the bottom for its three quick coats of high gloss varnish. In the past I had recruited my friend Terry to come over and help me turn the boat, but I was reluctant to do so this time. The boat is now significantly heavier than it was in the past and turning it has never been particularly safe for us or the boat. Instead, I used my rope-rescue training and equipment to lift the boat and turn it in a carefully controlled manner. It worked so well that I'll include some photos of my rigging the next time I update this blog. (With luck, that should be within a week and it should celebrate the completion of the boat!)

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Whoever wants to reach a distant goal must take many small steps. – Helmut Schmidt

Behold the turtle, he makes progress only when he sticks his neck out. – James B. Conant

Hell, there are no rules here – we’re trying to accomplish something. -Thomas Alva Edison

There will come a time when you believe everything is finished. That will be the beginning. -- Louis L'Amour