May 2023: The Fillets


I thought that I could finish my boat by just applying the techniques that I've learned so far. But no. I had read ahead, and knew that I had to apply "fillets" to the interior of the boat, wherever the panels join (those seams run the length of the boat), and wherever the frames (the horizontal pieces) meet the panels. A fillet is a mixture of epoxy and wood flour that fills in these seams, creating a smooth gradient, a rounded corner. I thought I knew how to do this because it involved just more peanut butter consistency epoxy.

The manual advises creating 12 ounces of this mixture, putting it in a pastry bag, or a heavy duty ziploc bag, cutting off a corner, and squeezing it out along a seam. Seasoned pro that I am, pessimist that I am, this sounded like a very, very bad idea. First, I've run into trouble mixing that much epoxy. Second, I can easily imagine the bag splitting open under pressure, dumping epoxy all over my boat, making the interior look far worse than it already does, not to mention, probably a month of cleanup. So I wrote to the forum.

Laszlo (among others) agreed with me, about the risk of the bag splitting open. He recommended applying the epoxy with a putty knife.

On one hand, I made basically no progress on the boat today. On the other hand, it was a day of learning. I experimented with fillets on the seam between the rear frame and the panels, behind the last frame. This area will not be visible in the finished boat, because it will be covered by the rear seat.

Lesson 1: So I mixed up some epoxy with wood flour, to peanut butter consistency, and tried applying it with a 1 1/2" putty knife. This was very thin peanut butter. Not really peanut butter consistency, if I'm being honest. This will be significant later. Anyway, it didn't work very well. I then noticed that Laszlo said that he used a rounded putty knife.

Lesson 2: I sanded down a paint stirrer to approximate a rounded putty knife.

And I tried applying some more epoxy. It sort of worked, but it provided very thin cover. The corner (between the frame and panel) wasn't really as filled in and rounded as I think it should have been.

Lesson 3: Back to the forums. I started a discourse on condiments. The epoxy/wood flour mix I used was more like thick maple syrup, pourable, but only slowly. Should it be more like Skippy? That is an extremely thick peanut butter, not at all pourable. Or should it be more like organic peanut butter? That is not quite as thick as Skippy, but thicker than maple syrup. Bubblehead answered, and suggested that the epoxy should not be pourable. He didn't address the condiments issue directly, but it sounded like he was recommending something closer to organic than Skippy.

So I mixed up a little of that, and applied it to a to-be-hidden area at the other end of the boat. And that seemed to work much better! I do realize that the difference is not really visible in these pictures, but in this last one, the corner is broader and rounder.

Bubblehead also suggested using masking tape on either side of the seam, to simplify cleanup, which is a good idea. Of course, cleaning up the masking tape can be difficult, but nowhere near as difficult as cleaning up epoxy.

So hopefully some actual progress tomorrow.

May 17, 2023: Actual progress! There was more advice on the CLC forums. Now that the condiment issue has been settled (the epoxy should be like organic peanut butter), there were other controversies. Use pastry bags to squeeze out epoxy along seams, or slather it on using a stick? What shape stick? Work cleanly and scrape up excess epoxy with a putty knife, or put down masking tape? How much epoxy in each batch?

I considered all the advice. I thought about my abilities in wrangling epoxy. I stroked my beard and furrowed my brow. And this is what I decided:

It seems to have gone well, and I got three fillets done today. Some choice views:

May 25, 2023. Dramatic sunset tonight.

I have been putting in 3 days/week on the boat this month, so things are moving along quickly. Last week, I finished the fillets between the frames and panels. Now, I'm working on the fillets where the panels come together. That's maybe 70 feet: six seams running the length of the boat. For each section of the boat (between frames), I apply masking tape around each of the three seams; mix 5-6 oz. of epoxy with wood filler and silica; apply it; smooth it out; remove the masking tape; smooth it some more; and then about an hour later, final cleanup using an alcohol-soaked rag. Just one section remaining.

Here are some seams before the fillets are applied:

And after (from different parts of the boat):

Here is one section with all the fillets done.

Once the fillets are done in the last section is done, I need to attach the centerboard trunk, and epoxy and install the seats.