[pianotech] cuddly die grinders

[Ron Nossaman]

On 10/27/2012 2:52 PM, Jim Ialeggio wrote:
> Those of you who abuse plates, that is grind off duplexes, or what have
> you, how do you get in close to either the struts or in tight sections
> without resorting to a file and bloody knuckles?

Never found a file to be useful there, though I've bled on just about 
everything at one time or another.


> I have  4" angle grinder which does most of the damage pretty quickly.

I'd like very much to find a more aggressive grit wheel for mine. Even 
36 grit clogs and wears too much. I need the equivalent of a wood rasp 
for cast iron.


> Then I often try to switch to a 1/4" die grinder, but that really
> doesn't cut the mustard, at least not the way I'm set up with it. The
> die grinder only uses "surface prep" wheels which are not aggressive
> enough, even the 36 grit, to take down serious metal.

Yep. Needs a 25-40mm grinding disc like the 4" angle grinder, again, 
much more aggressive a grit than I've found. I've found the discs good 
for stripping off the paint first to not clog the real grinder so much. 
Otherwise useless to remove iron.


>Any other
> approaches to the tight spots?

The best I've been able to do is an oval shaped double cut carbide 
rotary burr in an electric die grinder. It's awkward and slow, but does 
better (less miserable) for me than anything else I've found.


>Are there tiny grinding wheels for a die
> grinder,

If you find any, let me know. I haven't. I want to HOG those duplexes 
off instead of tickling them.
Ron N