Fixing the "mushroom" head of a chisel

[Julianna]

Hi.

I thought I had read something about this, but haven't been able to find it.

I am hoping to get rid of the the "mushroom" head on a chisel after extended use? My studio is quite minimal, and I don't have a stationary grinder (which I imagine I would need) but do have an angle grinder and a rotary tool. I tried using the angle grinder, but got some sparks which scared this stonehead (I'm much more accustomed to dust!)---is there a particular distance I should keep between the grinding and flamables (e.g. paper)? Is there a better method of taking care of this?

Thanks.

[sculptor]

Grinder or belt sander
either way, the sparks fly
keep a bucket of water handy
mostly, i work with wood so always have lots of planer shavings and sawdust handy to get the fire going really fast

if possible, grind so sparks fly against a flat surface like concrete, drywall or plywood---

my cousin, the blacksmith, set his garage on fire with a grinder, and I have shattered a glass patio door with the red hot sparks

fun stuff, like fireworks

get a stationary grinder with a buffing wheel --(do it now, and you can use it for another 3-5 decades)
I couldn't imagine working with any blades without one-2-3-or more, i've also got one where the stone passes through a trough of water.

I do my rough sharpening/shaping on a stationary belt sander, touch up the hollow grinds (for wood) on the grinders, then buff, dipping in an oil and water bath often---when I'm carving, I'll retouch the blade more'n once an hour so the buffing wheel is set up near the workbench

michaelangelo always set up his forge before carving the stone, and reshaped his tools often----

[dondougan]

Hi Julianna,

As long as you don't have the sparks aimed at anything flammable in about four of five feet the sparks will not be a problem - they cool-off rapidly. Just wear your safety glasses. And though you can use your SiC (silicon carbide) 'masonry' grinding wheel for the steel, an aluminum oxide wheel made for grinding steel will last longer and save your SiC wheel for stone. Another option is to use a coarse resin-backed sanding disc, but after grinding mushroomed heads off a couple of chisels the disc will be trash.

However, if you have a stonepile in the line-of-fire (even if twenty feet away or more) you may want to cover it up temporarily. The little flecks of steel from the grinding will land and then sit on the stone, then (with humidity and/or rain) will rust and leave speckled stains on your stone/marble.

[warren01]

Or if you like to use a little elbow grease a good bastard file could also be used. Mount your chiesel in a vise and go at it with a good file. If you do that routinely before the mushroom gets too big it would only take a little time. Save having the sparks flying around and metal dust all over.

warren

[Jay Long]

When you are grinding your chisel, put up a piece of plywood, or if you have a piece of sheet metal, about a foot away will keep most of your sparks close by, the plywood might get a little burnt, but it will not catch on fire, a 4 foot square screen will keep most of your sparks from going anywhere, also when you grind your chisel, grind a little inward taper to the end of your chisel, this will give you a longer life, before the chisel needs grinding again..........Jay

[tonofelephant]

A bench grinder is only about $40 - 50. But if no space to store it or whatever the reason, I have an alternate plan for you. Stop by either a place that sharpens knives, sawblades, etc and ask them to grind it off for you. Also could try a car mechanic shop or even a metal sculptor. They might charge you a buck or two but I doubt it.

Nothing else might be worth a try.

Carl
www.wsggallery.com

[G. Murdoch]

Julianna,

I won't add any more technical advice to the excellent suggestions already posted. Just say that it gladdens my heart whenever a stone carver has mushroomed the heads of thier chisels, for that only happens whilst beauty is being revealed.

Graham

[Julianna]

Thanks for all of the suggestions! Because of my limited space and money, I'll try the bastard file method for now.

[ewbrown93]

if you take the hand grinder to a outsind pluge the sparks wont matter myself use the saw blade it works just as good on limestone as it dose met.

[fused]

I've never worried about the mushroomed ends of my chisels.

[Julianna]

I ended up using the angle grinder...the bastard file didn't do much to the metal.

No fires yet... ;)