drill bit for cast iron

[ed440 at mindspring.com]

Why are you drilling through the plate?
This repair is usually done using the holes which already exist.
Ed Sutton

-----Original Message-----
>From: Bob Hull <hullfam5 at yahoo.com>
>Sent: Aug 24, 2006 12:32 AM
>To: pianotech at ptg.org
>Subject: drill bit for cast iron
>
>Drill Bit Question:
>
>Background: Yesterday I was trying to repair an
>Everett console that had a separation crack between
>the last lamination of the pinblock and the back beam.
> I guess it's glue joint failure and a downward
>warping of the wood from the downward pull of the
>tuning pins.  
>
>I made plans to install 3 bolts 3/8" x 5"L  after
>applying CA down in the crack.  However, drilling
>through the plate took about 45 minutes to do 1 hole. 
>I used a carbide tipped masonry bit per the suggestion
>of a industrial machine tool and  supply co.  I also
>tried using a 1/4" bit first and then progressing to a
>3/8" bit.  So, I wound up just installing 1 bolt due
>to time restraints.  
>
>I have done this repair a few times before but it's
>been awhile and I don't remember it taking this long
>to drill thru the plate.  I used a good low rpm
>electric drill vsr 0-600 rpms.
>
>Any drill bit recommendations?
>
>Thanks,
>
>Bob Hull
>
>  
>
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