Mushrooms and Maintenance

This little row shows the growth progress of ‘mushrooms’ on the heads of my chisels. Which raises the mushroom question – that is when to maintain chisels which inevitably become ‘mushroomed’ at the head due to use.  Some would be appalled to see these, in that they show total disregard to good housekeeping, or should I say tool-keeping.

If you are offended, look away now, it gets worse.

I really tend not to notice them – I’m concentrating on my carving, and as the metal splays I get used to the shape and feel of the chisel, and quickly dismiss the idea of removing the tops as it means I’ll have to get used to the handling of the chisel all over again. (This is important when I’m doing delicate or intricate carving).

I’m showing you them from different angles so you can see how the metal curls and splits as it gets pushed away by my hammer.  The tops become beautifully domed, soft curved and very pleasant to strike with my mallet.

The splitting of the metal however, is why there is a call for maintaining chisels regularly. Repeated hitting causes the folds of metal to become thinner and stressed, until they break off, usually in an unexpected direction.  These metal shards are really sharp and fly at speed, especially if I’m hammering hard, and can end up in eyes or implanted in skin.  It has happened to me, I didn’t feel a thing, but noticed blood, I couldn’t even see the wound.  Eventually I was aware of the smallest puncture mark in my finger.  Now I have a blueish stain under the skin, which is the metal shard, still embedded.  A sort of sculptor’s tattoo, or would it be piercing!  I was probably quite lucky – you do hear horror stories, of deaths even.

This is the chisel responsible.  It’s an old pitch nicker (used for splitting stone), which is usually positively struck with the hammer.  This is a big mushroom,  a split, jagged mess, and no surprise that bits broke off.

In the manufacture of chisels, tempering the metal and getting the right strength is critical – it needs to be soft enough to have ‘spring’ and usability, but hard enough to take hammering action.  Too hard and it just shatters.  Quite a balance – I tend to prefer chisels on the slightly softer side – but if they’re too soft they wear out before they’ve earned their keep.

Occasionally then, maintenance has to be done.   It is quite a simple process of grinding off the mushroom and putting a slight bevel on the top of the chisel to delay another one forming.

Newly maintained chisel, with the little shards (or as I call them ‘shrooms’) ground off the head.

Feel quite saintly after all that ‘Good Workshop Practice’.

I remember years ago having a conversation with an elderly, retired stone mason on this subject and he said – ‘it gladdens my heart whenever a stone carver has mushroomed the heads of their chisels, for that only happens whilst beauty is being revealed’.