Drilling holes in tile problem

Hi
I'm installing a shower enclosure and have to drill 10 holes in the wall to mount the rails. The problem is all holes are right on the edges of tile, (half on the tile and half on the grout). Enclosure cannot be moved so the holes have to be drilled in this bad location.
Any suggestions on how to get the holes a even/strait as possible and avoid drill bit drift to the softer material (grout). Holes have to be on center and are 5/16 in size. I'm using a tile bit that is 5/16.
Thanks, Martin
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On Sun, 22 Feb 2004 03:41:16 -0800, "Martin Hirsch"

Like everyone else, drill a pilot hole first. 1/16" would do it. Use masking tape to keep the smaller bit from wandering.
Jeff
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Martin Hirsch wrote:

I assume the rail is vertical and can't be moved in an out. So, you make a drill guide. Cut a piece of 3/4 inch hardwood that fits ceiling to floor and won't slip, drill holes at the correct distances, put the board in place, and let the holes using the board as a guide. Or, if you can put pressure on a board so it won't move, or use temporary double stick tape, you could just use a short board with one hole drilled in it.
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Hi Martin!
MH> I'm installing a shower enclosure and have to drill 10 holes in the wall to MH> mount the rails. The problem is all holes are right on the edges of tile, MH> (half on the tile and half on the grout). Enclosure cannot be moved so the MH> holes have to be drilled in this bad location. MH> MH> Any suggestions on how to get the holes a even/strait as possible and avoid MH> drill bit drift to the softer material (grout). Holes have to be on center MH> and are 5/16 in size. I'm using a tile bit that is 5/16. Eeewwwww!! I pity you!! As the other poster indicated, drill a pilot hole through masking tape with the smallest bit possible to start. Use even, steady pressure. Here I used a variable speed cordless drill; start slow to get the hole started and prevent drifting.
It will take "forever" for the drill bit to make much of a depression. Once it does keep going to establish a crater. This will be the base for the next drill bit - up a couple of sizes. Enlarge the crater for the next increase in size until you get to your 5/16". Again, steady but gentle pressure is the key.
For your requirement of the hole half in the grout, half on the tile, all I can thing of is to point the drill downward into the tile. The bit is going to drift naturally towards the softer grout. I'm thinking if you direct the hole into the tile at about a 45 angle you can use the 5/16" bit to 'file' the grout out and drill the final hole.
- barry.martinATthesafebbs.zeppole.com
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