Monday, September 22, 2014

Service

Of course splicing isn't the only consequence of my choice of galv wire for the rigging.  Stainless steel, one might assume from the name is a magical substance and free from the wroth and detrimental effects of corrosion.  In reality, not quite.  It certainly stays more or less shiny, but stainless steel's corrosive effects require the presence of oxygen.  Get seawater and stainless together in an anaerobic environment and watch the fun begin!  Galv, is certainly more susceptible to corrosion, and perhaps that's even a feature.  You don't assume that it won't rust, so you plan for it. And, when it starts to rust, you really notice it.  As long as you can sort it out soon, it is usually only cosmetic.  But galv isn't shiny, and it's not cool, so people don't like it.  It is cheap though, and I'm all about that!

Traditionally galv cable is treated against corrosion by what's called worming (not needed on smaller cables), parcelling, and serving.  I won't go into worming since I'm not doing it.  Basically what that means is you slather the cable in slush (usually a mixture of tar and linseed oil), then wrap it in long strips of tarred cloth, or cloth tape (parcelling), with the lay.  Then you tightly wrap that with tarred twine using a device called a serving board, or a serving mallet, against the lay.  Finally on top of that, you paint it with yet more slush, this time mixed also with some varnish and driers.  If you do all this well, and remember to re-apply more slush every year or two, you should have cable that last indefinitely.  Or so I've been lead to believe.

Sounds like a lot of work right?  Perfect for time wasting!

So I found a company that sells tarred nylon twine, which is what "The Rigger's Apprentice" told me was a good thing to use, and I bought some.  Memphis Net and Twine, by the way.  

TWINE!

Happiness is some warm twine?
I got some different sizes since I wasn't sure what would be best.  Although my bible, "The Rigger's Apprentice" is super awesome, it can sometimes be vague, or even contradictory in its details.  It's a good guide but you definitely need to experiment to figure out the details.  (maybe that's the intention?)

Plus, the twine is sold in weird sizes which don't correspond to the diameter or anything reasonable, but rather the weight (in pounds) of a certain length.  Americans are weird.

I can't remember the other sizes, but the one I settled on using was #30.

Now I had to make the serving mallet to apply the twine tightly to the cable.  The bible has many different drawings of a serving board/mallet, each different from the next, with no concrete information.  But I had a wooden mallet so I tried to replicated the one that looked like that.  The theory is that the twine must be wrapped very tightly, and the mallet gives the required leverage for that.

Looks ok
I cut a groove in the top of the mallet, like in the pictures, and attached a fancy spool holder!

One of my favourite knots, the icicle hitch
I stretched the cable between two points nice and tight and gave it a burl.

The twine is wrapped around the handle to give an even tension

OMG, service?
I didn't bother with the parcelling, or any slushing.  Just wanted to get the feel of applying the service. It's a bit tricky to start off since you have to wrap the service over the end of the twine.  Likewise, ending the service requires some more trickiness, which I won't go in to now (how annoying of me!).

Serviced cable around a thimble and snug in the vice.
Of course at this point I realised that all the galv thimbles I had bought were now useless.  They were 6mm, which made perfect sense at the time.  Thimbles to match the size of the cable right?  Of course I forgot all about the service.  The twine I had chosen was almost 2mm in diameter, so I figured that with all the stretching and compressing of it, it would probably be safe to go with 8mm thimbles for a nice tight fit.  Also one extra thing I didn't think about when I got the galv thimbles was the fact that unless I also had galv turnbuckles, they'd have to make contact with stainless.  And even if I got galv turnbuckles, unless I replaced the chainplates (not right now thank you) then a galv turnbuckle would be in contact with stainless too.  Why is this a problem might you ask?  Well apart from the fact that it's a little more difficult to tar, parcel, and serve thimbles and turnbuckles, the contact of the two different metals would lead to galvanic corrosion, especially bad in the presence of a salt solution (aka seawater).  So I figured that using stainless thimbles that would never come into contact with the galv cable under its protective covering of service and slush, I'd be OK.  Plus, I'd already bought a bunch of stainless turnbuckles.

The metal squid!

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