Mushrooms and Maintenance


Row of chisels

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.

Stone carving chisels

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).

Stone carving chisels

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.

Stone carving chisels

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.

Old chisel

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.

Chisel in need of maintenance

chisel with mushroom ground off

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’.






  1. Comment by countrysidetales:

    What a fascinating post. Are stone masons’ tools made by craftspeople themselves, or just mainstream manufacturers? I’m glad you’ve removed the shrooms- the potential for injury doesn’t sound like something worth taking a risk with. Love the quote at the end :o)

    • Reply by Jennifer:

      When I first started out, and was looking for a hammer, I was told of a company who made them. I visited this extraordinary premises, ancient, all on a slope with wide wooden floorboards and long rows of small windows. The owners were clad in leather aprons and talked with their spade wide hands. I was measured up for the hammer (like for a suit) – so that it was the right weight, length, balance and handle – I had to wait months as it was made specially. It was expensive, but will last my lifetime (at least). By the time I’d saved up for another, and visited, the maker’s workshop was no longer there, just planning notices in its place. A lot of tooling is imported now – but there are British makers, who understand metal and stone carver’s needs from whom I buy – I love visiting them! Gone are the days I think, of stoneyards having their own dedicated blacksmith constantly making, sharpening and repairing tools.

  2. Comment by Amanda:

    The old man’s quote at the end is beautiful and he is right, your tools are been used and worked to produce beautiful objects, I love the photo of the large chisel ( pitch nicker )you can see it has been used, loved and worked…
    Amanda xx

    • Reply by Jennifer:

      Thankyou Amanda – you know that pitch nicker – I don’t use any more now, but I love it so, we have great memories that chisel and I – in fact I’m a bit of a hoarder when it comes to old tools!

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