Friday, January 13, 2012

Oooo, la la

So were you expecting a trip into the deepest corners of the w'shop to find the Mythical O-Ring fields, wherein these useful fittings grow in plentiful profusion, just ripe for harvesting. You weren't? Just me then.

No, I knew exactly where the O-rings were, so that was the easy bit. See? Add in a length of nylon cord that I got in amongst a bag of reel ends from a chandlers about 25 years ago (Please refer back to the phenomenon of Things That Will Come In Handy from yesterday's post), coupla bowlines, and behold. Proof of concept.

Mrs F was so-so about it at first, but once she'd discovered that the hexagonal nuts weren't actually going to hurt like she thought they might, happiness ensued and it's been worn extensively. Not a thing of beauty, but a joy for several weeks anyway. Now I really need to find out if such a thing as a clear O-ring exists, and whether it'll work if they do. And find some beads so I can get my brass nuts back...

But the observant may be raising a hand at this juncture, and pointing out that I claimed happy w'shop results plural. i.e. More than one. So onto number two we go.

The reason I have a selection of O-rings at my fingertips is not because I wanted to make some sort of Olympic symbol, but because of coping saws. Or rather coping saw-sized bow saws. I like coping saws for dovetailing; can't get along with piercing saws at all. I've tried, but just, no. Not for me. Not that I was getting along with my coping saw that well either, really. Couldn't find a decent one at all. (Does this sound familiar to you? The Schwarz and I are actually clones - only he got all the skinny genes and I got the shorter haircut...) Legend told me that the older Eclipse was the best one to get, but despite legend also telling me they were two-a-penny at any boot sale of your choice, I simply never saw one. In the meantime I even resorted to trying the modern Bahco model, which merely demonstrated that throwing money at the problem only made it much worse. BugBear came to my rescue one Christmas though, and furnished me with this shiny beauty:

Now the Eclipse is pretty good for applying tension on the blade, which is usually the major problem with inferior coping saws. I mean really pretty good. But like the unloved Bahco - although not anywhere near to the same infuriating level - it still has a nasty tendency to allow the blade to swivel when you don't want it to. The very feature of a coping saw that I so prefer over the fixed blade piercing saw is also, in fact, its Achilles Heel.


So, in a bid to improve the coping saw experience, many a user has ended up making a bow saw sized to take coping saw blades. They're very beautiful, apply loads of tension, and... still apparently some of them swivel when you don't want them to. But some don't. So I've had one on my To Make List for several years now, in the hopes I'd hit the magic formula and make one that resolved all my coping saw issues. I read all I could find on them, saved all the pics, in short did my usual prevarication cunningly disguised as in-depth research.

No, I still haven't made one, but I did start to gather together some of the necessary hardware last Christmas.

Ah, no. The Christmas before last now. Whoops.

Anyway, somewhere, and I can't for the life of me recall where, I read someone had worried about the fact that the old full-sized bow saws used to have tapered rods that actively wedged themselves as the tension was increased, thus negating the tendency to swivel, but what about this small version with parallel rods? So they decided to fit it out with some O-rings and behold, it worked and the thing didn't not swivel unless actively demanded so to do.

So I also procured myself some O-rings for when I made that coping saw-sized bow saw.

Why on Earth the penny took so long to drop, I have no idea, but as I threaded the doubled-up O-ring through the brass nut for the spectacle chain, I suddenly wondered "Self, would the O-ring idea work on our existing coping saw?" I had the O-rings, I had the coping saw - 'twas but the work of a moment to find out.

The Eclipse tends to swivel most at the handle end (The Bahco isn't as picky and swivels at both ends...); after trial and error, I found it worked better with the O-ring here, rather than between the handle ferrule and the frame.

The other end has no other option than this, but it works.

Boy, does it work. I'm not holding back in trying to get this thing to move once the blade is tensioned, and it simply does not budge.

A very quick and dirty cut in some seasoned oak with the blade swivelled to an angle. Didn't move a jot, and I certainly didn't coddle it.


Now I'm sure I can't be the first person to do this, but as a tip it seems to have utterly passed me by. So here it is, just in case it's passed you by too.

Of course it may not work for every coping saw. The fit between the blade holders and the frame on the Bahco is so atrocious there's not enough for the O-ring to bear on in order to do the job. Sigh.

So that's it; a long way round to saying "Made my mum a spec chain and improved a coupla tools". Next week - woodworking.

Nah. Just kidding... ;)


  1. Great tip, Alf. Must try that out (on the coping saw, not the specs). Now, where did I put those O rings.........

    Cheers ;-)

    Paul Chapman

  2. Thank you, Alf. I've suffered secret shame for many, many years because my coping saw blades insisted on swivelling at the most inconvenient moment. The cut would then wander or worst of all, the blade might break.

    I thought I was the only one with this affliction. Now I can face the future! Huzzah!


  3. I just went and checked my Olsen coping saw. There is a spot I can put a couple of o rings. Tomorrow I'll get some and give it a try.
    I hope it works for me.

  4. Very good tip. Thanks
    I have just that Eclipse coping saw brother in law is hydraulic.

  5. Shucks, gosh, and golly darn.

    Off to the hardware store for me, I think...

  6. Wow so simple yet who knew . .. now thanks to you we do... this will make my life easier.


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