Monday, January 07, 2008

Drowningly

So spent a little time dimensioning some stock for the doors for the you-know-what. Then groovin'...


...to end up with stiles and rails like so. Made the classic greenhorn error and used a fence face that was too deep for the narrower stiles; luckily t'was a simple matter to slip the 044 cutter into the 043 and complete the job. But still "d'oh".


Then selecting the only 1/4" mortise chisel (with a handle) that actually fitted the groove ploughed by the alleged 1/4" cutter. Viz: a Marples sash mortise chisel...


...successfully whacked out half the mortises. Well as far as I know they're successful; things going as they are, anything could reveal itself if I ever reach the tenon-fitting stage.


All was going splendidly on the other four mortises right up until this happened:

Either:
a) I don't know me own strength, guv.
b) The slight pitting on this pre-owned chisel was more serious than it appeared and weakened it slightly.
c) It hit a rather harder area of wood - possibly corroborated by the presence of a chip in the edge which wasn't there before the fatal blow.
d) Combination of two or more of the above.

I've not checked to see if it's still tempered beyond the break point (might also be a factor?) so I don't know if I can just grind a fresh bevel and carry on. Failing that I have a socket chisel of the right width (really don't want to complicate things by having different width mortises in different places, or spend my time trying to enlarge the finished ones). Only problem is it needs a handle, as do its two socketed companions, and I really didn't intend to get into a spell of chisel re-handling. After all, once started who knows when it'll end...

So other than that it all went swimmingly. After that it tended more towards going drowningly.

On the plus side, let me point out the wisdom of having alternatives available in the form of a wide variety of tools from which to choose. Hmm? See? Not always as stoopid as I look...

8 comments:

  1. Alf

    Remind me not to get into a wrestling match with you!!!

    When you say that you were whacking out the mortises, do you mean that you were removing all the waste with the chisel? Did it snap when you were hitting it or when you were levering a chip out?

    My Dad taught me that you shouldn't use a chisel as a lever - ie the chisel should either cut shavings or chips of its own accord and you shouldn't push down on the handle to lever a chip off. I didn't believe him either until I snapped a chisel doing that.

    As a result, I use a drill (usually, a bit and brace) to remove a lot of the waste in a mortise before moving to the chisels to square everything up.

    We live and learn.

    Cheers

    Jeremy

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  2. Alf,

    Did it happen whilst you were bludgeoning it or during levering?

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  3. Peace, gentlemen - it was probably largely my fault, yep, hence my lack of raging against the tool gods ;) Time was moving on, I wanted to get it done, got over-confident, whacked it in a little far and bust the thing getting it out again. Usually I wield an OBM which thinks nothing of such a task and didn't make sufficient allowance for the comparative weediness of the sash mortise. I would say I live and learn, but apparently what I actually do is live, learn, forget and have to relearn!

    As to boring and then chiseling, I just don't get along with it on such small mortises. I find it slower and less accurate. A relieving cut at one end and then working down the length, gradually getting to depth, then working back to clean up the resulting slope is my preferred technique.

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  4. Alf- I have a chisel from that same set: I've had the very same thing happen with a Marples 3/8 sash mortise chisel. I don't remember the full circumstances, but I don't think I was pushing the chisel to anywhere near its limits. The experience left me with the lingering suspicion that these chisels aren't up to snuff.

    If Ray Iles is reading this, maybe he will lend you a tester. Now that's a mortise chisel.

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  5. Alf,

    Just to clarify... was it simply stuck in the timber and it required some robust levering to dislodge it, which resulted in the fracture?

    Such a clean break with no elastic bending prior to fracture indicates to me that the area in question was quite brittle.

    I will expose my ignorance. What, pray tell, is an OBM?

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  6. Sorry ALf, can I ask for slightly more clarity...the relieving cut, can you define it more clearly for a newbie, is it 'full depth', and is it made with the chisel or the bit? And if made with either one, might it be made with the other? Wonderful work btw, but sad about the chisel! Thanks, as always, for the learning, and Happy New Year!

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  7. Old Baleine, what an excellent idea re: Ray Iles; I like your thinking! ;-)

    Jeff, yes, it was a certain amount of levering during removal when it gave way. Like you I was surprised it didn't bend first. At the risk of sounding as if I protest my innocence too much (!), thinking about it again today it really did break a lot more easily than I'd have expected. And apologies; an Oval Bolstered Mortise chisel, sometimes colloquially known as a "pigsticker"

    Anon, I'll bore the multitude with a few pics in the next entry in the hopes that'll better explain it :-)

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  8. Glad to see proper work holding for morticing...

    http://www.geocities.com/plybench/tour.html#mortice_hold

    BugBear

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