Sunday, March 24, 2013

Worn-out seat

Owing to me = big fan of Wittgenstein, this blog has been silent for a while. Actually that is a lie. I'm not a big fan of Wittgenstein. Nobody is. Proposition 7 is the only one I know about. Proposition 7 is in fact the only one anyone knows about. An entire life devoted to revealing the obvious. Though it's always surprising how many users of the Internet speak whether we have something to say or not.

And anyway that is two lies. It's nothing to do with Wittgenstein. It's to do with me = lazy.

I now have something to say, though whether the Internet needs to be cluttered yet further with the details is another matter.

This week I was faced with a problem. My recumbent's seat has worn out. Specifically, the lower two bits of webbing - where the pelvic girdle rocks - have worn and started to fray. The wear was predictable.  Initially I thought a quick sew-up job, but removing the offending piece of webbing revealed the not altogether startling fact that the rusty staining in the webbing was caused by a rusty frame, and the rusty frame was caused by chafing of the paint by the webbing, plus sweat. One always sweats on a recumbent, owing to the need to excite admiration and envy at one's uncommon bicycle.

 Frayed seat webbing

Removing the rust revealed quite deep pitting, so it's more of a problem than I'd thought. After priming and topcoating several times, it occurred to me that I wasn't going to overcome the chafing by doing the same thing again. Eventually I thought of epoxy resin, but knowing how epoxy doesn't always stick to paint I thought of glass fibre, and when I'd finished thinking of that and realised it added pointless strength and isn't very nice to work with, I settled on epoxy torn-up-cotton-shirt.

So 2" wide cotton strips were painted with epoxy and helically wrapped onto the seat-frame sides. Then, meticulously, I wrapped the whole in stretched strips of inner-tube, which doesn't stick to epoxy resin, and left it in the sun. It didn't harden as quickly as it should, probably because lacking syringes I'd measured the 4:1 ratio resin-to-hardener with a teaspoon.

Glued and bound
 Partly unbound


It hardened overnight, but pulling off the rubber revealed another problem: little ridges of epoxy at the edges of the rubber binding. The ridges sort-of carved off with a scalpel but didn't leave everything smooth, and sanding with an orbital sander exposed too much white to make me confident that the cotton wasn't somehow going to wick moisture down to the metal in the future.

So then I thought of re-varnishing with epoxy, and it occurred to me that two of those empty 9mm pistol cartridge cases that we'd picked up at the rifle range to make Trench Art would make nice measuring cylinders, it being a Sunday and me lacking access to syringes stolen out of the surgery. In the event only one was needed: four measures of resin, followed by one of hardener, each carefully drained out, and then mixed thoroughly with one of the saved ice lolly sticks that so irritate my wife as we stack them up in the kitchen.

 Measuring cylinders


The epoxy was rubbed hard into the sanded cotton with the lolly stick and then I set to work sewing up the frayed webbing, a huge waste of time since it would have been far quicker to cut new webbing and make new ends. But I'm stupid like that. With a bit of luck in a few years I'll be able to report that it worked.

While I had the seat off I replaced the steel neck supports which so contribute to the huge weight of my machine. They weigh a pound. Now they're thin aluminium tubing, plugged with hardwood instead of bushings but they still weigh half a pound. The saddlebag weighs five pounds, but that's because I pick up bling from the side of the road on the general principle that while it might add fifteen seconds to my journey to stop for that 10mm bolt that I don't need, it'll take a lot longer to make a 10mm bolt if ever I need one. It's a principle undermined by the fact that my shed is so full of roadside rubbish I can never find the bit of bling that I misremembered picking up. (What is bling, anyway?) It's also undermined by the fact that I'm too lazy to empty it out of the saddlebag.


In a wholly irrelevant aside, how is a solicitor so qualified as to be worth fifty dollars for two minute's expenditure of ink and the vast manual labour of signing a statement to the effect that he has seen a birth certificate? And in another wholly irrelevant aside, you may now take it that Yahoo have neither clue nor insight into anything to do with the News.

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