Thursday, November 10, 2011

Watertight

We just finished caulking the quarterdeck of the brigantine Irving Johnson.

The first step in this job is cleaning out the old pitch and oakum from the seams. This is called reefing. (I didn't get a photo of the reefing tools, but there are some nice ones here.) Beneath the oakum is a layer of cotton, which you only need to replace if it's wet.

Oakum is a kind of loose fibrous stuff which is hand-tarred and rolled into usable lengths. (Wikipedia notes that "Oakum was at one time recycled from old tarry ropes and cordage, which were painstakingly unraveled and taken apart into fiber; this task of picking and preparation was a common penal occupation in prisons and workhouses.") We've been referring to it as dreadlocks, due to its resemblance to light brown hair that hasn't been washed in several months.

Once you get the hang of it, reefing is all right. When the pitch is out of the way, the oakum tends to pull out in huge long strands, making you feel like you're really getting something done. All right!

Then you put in new oakum, using a mallet and a couple of caulking irons:


One iron has a fine edge (single crease), for tacking the oakum into place, and the other has a broad edge (double crease), for smashing it all down flat. This is the most labor-intensive part of the job. Getting enough oakum pounded down into that seam requires a lot of hammering, and if you've overestimated the amount, it may have to be torn out and redone. This is excruciating because it's already taking for-ev-er aughh whyyyy.

Then you melt down your pitch (well, traditionally it was pitch, and we still called it that, although we used Jeffery's Marine Glue). We did this on the dock, with a fire extinguisher handy.


While you're waiting for it to liquefy, you can blue-tape all the seams. This step isn't traditional, but it sure does make the deck look cleaner immediately after application. (Ultimately, all the pitch that isn't in a seam will get worn away, so it's not absolutely necessary, but it will make you feel better when you slosh pitch all over the place.)

Then you pour the ultra-super-hot pitch into this pyramid-shaped iron device with a spout on the end, and you use it to apply the pitch to the seams.


A diagram on this page tells me it's called a "pitch ladle," although we referred to it as the "pitch gun." Whatever you call it, be sure you're wearing welding gloves, because that thing has no insulation whatsoever.

The blowtorch is useful because the pitch cools very rapidly and must be heated up again every minute or two. Through the entire process, I was curious to know: what on earth did they do in the Age of Sail, when there were no blowtorches? I spoke to a sailor who worked on another deck caulking project, and he said they didn't have a pyramidal applicator like we do; they used a pitch pot, which they heated right on deck and poured directly into the seams. When it started to harden it up, they put it back on the burner. Then they used seaming irons to smooth out the seams. We didn't have seaming irons, but blowtorches were probably more fun anyway.

Before the seams cool completely, you go back over them with chisels and remove the excess pitch. (If the seam is already cool, you can use the blowtorch to heat the chisel or the seam to make it more pliable.)


Then all you have to do is remove the blue tape and scrub down the deck. Here's an old seam and a new seam for comparison. (We left the old seam because it was in perfectly good condition.)


Voila! It sounds so easy, doesn't it? But only if you know what you're doing, which we didn't when we started. And only if it stops raining long enough for you to get the work done. And only if you have enough people show up to make the work go quickly. So, yeah, not really easy. But we did it. Only 2/3 of the deck to go!

2 comments:

  1. So... easy "only if you know what you're doing, which we didn't when we started. And only if it stops raining long enough for you to get the work done. And only if you have enough people show up to make the work go quickly."

    Sounds like fun! We need to get this done on Baltia before it rains more!! Leaky cabintop. Fun times.

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    1. Yeah, effectively not easy. I am still itching to come help out with Baltia, but keep heading in the wrong direction, geographically speaking. I take a curious comfort in the fact that there is no end to the bosun's work; it means I can just about always come over and play maintenance with you.

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