MYBOAT

Confessions of an Epoxy Hater

Like many wooden boatbuilders, I have a love/hate relationship with epoxy.

On the one hand, I love the results. For example, the laminated boomkin I am about to create. On the other hand, Im acutely aware of the toxic nature of epoxy, and the very real threat of an allergic reaction. I had an allergic reaction to penicillin once, and dont care to repeat the experience.

So Im very careful to wear long pants and long sleeve shirt, with gloves (I like the more expensive nitrile gloves), and mask; and to work in a well ventilated area. And I urge my readers to do the same, if they decide to try this at home.

With that sense of caution, I strapped on my chemical warfare armor, and got to work on the next stage of my boomkin build.

Id given my steam bent hickory 2 days to cool and dry. The Wood Handbook says drying is an important part of the wood retaining its new shape, so I didnt rush it. The photo below shows the wood still clamped to the the form.

BEFORE unclamping the wood, I drew some index lines. These were pencil lines that I hoped would help me reassemble the pieces correctly.

First, I drew a pencil line, straight across the top of the 5 boards, at the far end. Id use this line to make sure all 5 boards were lined up properly, in relationship to each other. When the boards were lined up properly, the lines on all 5 boards would also line up.

Second, I drew another pencil line, on the right face of the right most board (in the photo below), right next to the first form. When all 5 boards were glued together, Id use this line to make sure the whole assembly was lined up correctly on the forms.

This is a very important step, I think, but I hadnt seen it mentioned in any of my boat building books. Luckily, Id learned a similar lesson the hard way when building the station molds for Cabin Boy. Fool me once!

Dont forget to draw index lines before removing wood from frame!

Here are the boards with the clamps removed. As you can see, the wood held its shape pretty well. In fact, better than Id expected. The wood really was a different shape.

With clamps removed

As usual, I had no idea how to actually do the gluing up, so before starting, I did a little research on the West Systems website. In a nutshell, there are three steps:

1. wet out the two sides to be glued with an untracked epoxy/hardener mixture.
2. apply a layer of thickened epoxy/hardener mixture
3. clamp 

I used the 206 Slow hardener, which has a 20-25 min pot life, and 90-110 minute working time, just to keep my stress level low.

I set up an epoxy workstation, as seen in the photo below.

I used two plastic paint roller trays (purchased at HD for half the price at WM). One tray was for the unthickened epoxy, and one for the thickened stuff.

Theres no hard and fast rule for adding thickener, but the idea is to end up with something with the consistency of catsup.

I thought I could roll on both, but the thickened epoxy was a bit too thick for a roller. I used an old paint scraper to spread the thickened epoxy as smoothly as I could.

Epoxy station

I proceeded in a calm, methodical, but rapid process, first mixing up a batch of epoxy just big enough for gluing two boards together. I didnt want epoxy just sitting around for the whole process, but Im not sure if that would have been a problem.

I mixed up the unthickened batch, using a digital scale to get the proportions right. I used 4 oz of epoxy for each batch, with .8 oz of hardener.

Then I rolled it onto both surfaces, to wet out both surfaces.

Then, I added thickener to the remaining epoxy, and spread it onto one of the boards (the right one, in this photo). If I noticed any holes in knots, for example, I was careful to fill them with thickened epoxy. There were just a few small knots that needed this treatment.

Finally, I put the two glued faces together, lined up my index line, pressed the boards together with my hands, and quickly moved on to the next two faces.

Both boards wetted out, and one slathered with thickened epoxy

Pretty rapidly, all 5 boards were glued together, and it was time to clamp them back onto the form. By that point, I was too preoccupied to take a picture, unfortunately!

However, it was no big deal. Even though the boards werent clamped together, it was easy to roll the 5 glued boards together on their sides, and slide them into the curve of the form.
Then, starting at the far end, I quickly clamped the boards to the form, being careful to clamp them tight enough to get some squeeze out, but not so tightly as to squeeze out all the epoxy.

Initial clamping

I did that initial clamping quickly, but then went back along the whole line and used the plastic wrap on the table to make sure that none of my clamps or wood pads would end up glued to the hickory.  Basically, I just wrapped the left side of the hickory in the plastic wrap, and then put the pads and clamps on the outside of the plastic.

I also added a few additional clamps between the forms, wherever it looked like the joint needed more pressure. Every clamp I own is in action in the photo below. If Id had more, there would be more in the photo!

Add caption

Finally, I tried to clean up as much of the squeeze out as possible, first scraping it off with my paint scraper, and then wiping the rest up with a rag. Better to sacrifice a rag than to have globs of hardened epoxy on the finished product.

One problem: what to do about the squeeze out on the bottom?

I dont have a solution for that one. Im sure it will be a big mess that I will complain about, bitterly, in a future blog post, but I dont know what you can do about it. If anyone has a brilliant idea, Id be glad to hear it!

The whole process took about 1/2 hour, which was well within the bounds of the 206 hardener. Ill give it a good 24 hours to dry, and pick up the story from there. The next step is shaping these glued up boards into something that looks like a spar. I really have no idea how Im going to do that, but I guess I will think of something...

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