Glued up the mast on Saturday. I had two helpers and it took us about three hours, though we were not in a rush at all.
Here are some pictures of everything clamped up. Below, I’ll talk about the process.
Before glue, we clamped everything up dry and studied it for a while. I was interested in how many clamps I would need and how well my bowed pieces would straighten out. And in general, what my sequence would be once I started mixing epoxy and the clock started ticking.
Epoxy and Plugs
For the mast plugs, I stole an idea from Stephen Holmans to screw in a little eye hook to the outer end of the plugs so that you can adjust the plugs if they move around in the glue.
Prior to the day of glueup I had rolled the inside faces of the staves with unthickened epoxy to help seal the wood. The manual advises this to help keep the mast from warping. Then I rolled a second coat the day of glueup. With this second coat I also hit all the mating faces of the staves in order to help keep the thickened epoxy from being soaked into the wood when applied later. (I have been doing this on all my surfaces that get thickened epoxy)
Be warned, this job takes a lot of thickened epoxy. During this build I have been impressed that my mixing estimates have been so good, especially compared to my first build. But I was WAY off on the mast. It was almost strange. I must have mixed 4-5 batches, thinking each time that surely I now had it right. It got to the point I was getting a little panicked about time. I was very glad to have two people able to brush on epoxy while I was able to measure and mix. The manual advises having a helper here and I found that wise.
I wish I could report the total quantity of thickened epoxy I used but in the excitement I did not keep count. Sorry. But the unit of measurement is not a word you’d use in front of your mother.
Bow in Mast
As I have mentioned earlier, two of my four mast staves were a bit warped and bowed. I was hoping that simply clamping up the staves would straighten things out but the end result was that the top 48″ of the mast bowed out slightly to one side. The bow was probably about a half an inch.
I am assuming that if I can clamp the mast down straight, it should cure straight.
We tossed around several ideas for doing this. In the end it was pretty easy. My spar benches are 3″ pieces of straight and flat angle iron. So we started at the base end of the mast and began clamping down to the angle iron (the flat aft face to the iron). As we worked our way ‘up’ the tapering mast, we would simply observe the amount of iron surface showing on either side of the mast. As long as there were equal amounts, then the mast was straight. So we would just pull the mast and clamp it centered on the angle iron. I would like to say we used calipers or rulers to measure exactly but we just eyeballed it. If all three of us considered it centered, then it was.
As of this post I have yet to unclamp the piece, so I cannot say if we straightened out the bow or not. We’ll see.
One Last Thing…
In an earlier post I mentioned that my side stave rabbets were a little messy up at the top end because I ran my table saw without a throat plate. Well, after that post, the throat plate I ordered had arrived. So, since I had that on hand, I took the opportunity to clean up the messy rabbets.
Where the rabbets were too deep I filled in with thickened epoxy, colored with wood flour. After this cured, I ran just the ends of the side staves through my table saw again. My dado stack was still set up properly but now with a throat plate, the stock ran through flat and cleaned up the rabbets nicely.