Replies

1. 
   p_m | Mar 10, 2002 07:13am | #1

   *
   Harbor Freight, the reknown vendor of whatever, seems to sometimes offer a diamond [studded] hole saw in one inch diameter in their flyers. I haven't tried it or even have one but thought I might mention it just to have something worthwhile to mention.
   Another option is a one inch diameter .50 caliber machine gun bullet. Wear ear muffs.
   -Peter

1. 
   Karl_Isacson | Mar 10, 2002 08:29am | #2

   *Don't do it unless it is your own sink! I am a granite fabricator and in the past have been asked to drill and extra hole in an undermounted cast iron sink for additional plumbing fixture. I used a 1 3/8 diamond core drill (check out braxton bragg if you want to buy one)and it goes through both the cast iron and the granite covering it quite easily. The problem is that the porcelain/enamel/? coating on the cast iron ended up chipping off in flakes around the hole. Fortunately the caulking around the polished sink hole in the granite covered the chip otherwise I would have been confronted with trying to remove and replace a sink from below the countertops. I give myself a 25 to 50% chance of pulling that off successfully. I did keep the core drill wet to reduce heat buildup and to lubricate it but I have no interest in further experimenting on someone elses kitchen.The plumber made it sound like there are outfits that specialize in drilling holes in cast iron fixtures but I don't know who to call.Hope this helps.karl

1. 
   Brian_Smith | Mar 10, 2002 09:02am | #3

   *porcelain chipping is the problem.plumbers/supply houses will recommend a bimetal hole saw (also recommended for steel doors). tried it a couple of times. ehh. my engineer boss decided to cut through countertop instead (this was for DW air gaps). the diamaond hole saw sounds better.if you chip the porcelain badly and the faucet doesn't cover, get a porcelain repair kit for $20. good to have around for backup.here's their phone #: (877) 492-8711 here's their website: http://www.bathtubrepair.com brian

1. 
   Treetalk_ | Mar 12, 2002 03:10am | #4

   *If its like the diamond coated core bit I got at Lowes its pretty coarse.This one looked like it was coated with road gravel!

2. 
   user-38255 | Mar 28, 2005 06:07am | #5

   Thanks for the info. I did attempt to drill it using a masonry bit to get through the enamel and a cobalt bit for the cast iron. I was very successful up to the end of the drilling process when the area around the hole suddenly chipped out.  I used water to cool and lubricate the area as I was drilling, but I'm sure the vibration of drilling and the speed that I was drillig at was more than the sink could handle. I was so foolish to have attempted it. I now have a nice chipped out area that is not covered by the cover plate. Fortunantly I do own the sink and my wife has poor eye sight, and is just happy to have filtered water now at the sink.

1. 
   JohnT8 | Mar 28, 2005 08:43am | #6

   Can you substitute a larger coverplate?

    jt8

   Opportunity doesn't knock. You knock, opportunity answers. -- American Proverb

2. 
   CJD | Mar 28, 2005 05:40pm | #8

   An unprotected porcelain chip on cast iron sink is a problem because of rust. Perhaps you could get some solid surface material (Corian or similar) and have a larger cover plate made that can be sealed to the sink? You may also be able to find larger chrome plated brass cover plate at a commercial plumbing supply.

1. 
   user-38255 | Mar 29, 2005 07:38am | #13

   Thanks for the great input.

3. 
   BillHartmann | Mar 29, 2005 04:37pm | #15

   I would get some of the touch up paint. It is availble in any hardware or home horror store. Not so much as to hide the chip, but to keep it from rusting.

2. 
   lwj2 | Mar 28, 2005 10:09pm | #9

   Another option is a one inch diameter .50 caliber machine gun bullet. Wear ear muffs.
   ****************You'd need a 25mm for that. A .50 cal is just that, half an inch, 12.4mm.:)Leon Jester

1. 
   MarkH | Mar 28, 2005 10:53pm | #10

   The last time I tried a 50 cal on cast iron, it made a lot of mess. I recommend using a plasma arc.

2. 
   UncleDunc | Mar 29, 2005 12:17am | #11

   12.7 mm:)

1. 
   lwj2 | Mar 29, 2005 04:15pm | #14

   Must have been the flu, Unc, my math skills are usually better than that.If anyone tries to do that with a Bushmaster, do take pix and post them, please.I've seen what a Barrett does to cast iron frying pans.Leon Jester

2. 
   Alphonse | Mar 28, 2005 01:51pm | #7

   A hole saw will work.To avoid chipping porcelain either spread a thin coat of epoxy to cover the ID/OD of your proposed hole prior to drilling the pilot,or mark the outline and use a stone/abrasive disc in a Dremel to remove the coating before hole sawing.

3. 
   JohnSprung | Mar 29, 2005 03:21am | #12

   Machine shops work on cast iron all the time.  Generally, you cut it dry, low RPM's, high speed steel tools work fine.

    

   -- J.S.