# holes for black pipe (drilling odd sized holes)



## crossedout (Jan 15, 2010)

I am loving LJs. Lots of quick help out there. Here's my next question:

I'm working on a franken - Rubo / New fangled styled workbench. It will have the pipe clamp workholdings like the new fangled with the thick heaviness.

I'm using a solid 5" thick top and want to drill holes thru the center at 6"/6"/6"/6"/12"/12"/40" to put in 3/4" pipe clamps. I'm trying to drill the right sized holes thru each layer of the lamination of the top. But the OD of the black pipe is just larger than 1 1/16 inch. I can't find a drill bit that will make this fit snugly, but not tight. I used a 1 1/8 inch paddle and forsner bit, but they both are a bit sloppy.

How does one make a properly sized hole when there doesn't seem to be a drill bit to fit? I've used the "wiggle the smaller paddle bit around in the hole to make it a bigger hole" method, but I don't want it to be sloppy. Several layers with the same hole need to be glued together and lined up.

Thanks for your help.
Brad


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## jayjay (Jan 22, 2010)

If you have a grinder, you could grind a little off the outer edges of the 1-1/8" spade bit. Those bits are relatively inexpensive, so modifying one wouldn't be a big deal.


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## dfletcher (Jan 14, 2010)

Do they make metric bits? If they do, I would think this would be the right way to go.


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## albut (Apr 16, 2008)

drum sander on drill to over size hole a little bit

http://www.leevalley.com/wood/page.aspx?c=1&p=42502&cat=1,42500,42501


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## oldworld124 (Mar 2, 2008)

You can drill the holes a bit smaller and then use a router and jig with a template guide and long bit. You can then clamp the jig to the table top and make the holes cleanly. You can most likely reach to the middle of the table and flip it over and repeat the routing.


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## jerseyshore (Dec 7, 2008)

Try using a hole saw 1 1/8 " is standard for a 3/4 pipe; make sure your pilot bit is sharp, use very light to medium pressure after you sink the pilot bit.


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## crossedout (Jan 15, 2010)

Wow. This is probably the most active forum (of any topic) I have ever looked at. In addition, the general attitude is very humble and extremely helpful. Many other forums it is "I know more that anyone" attitude. I love it.

Great suggestions everyone.

When I took another look i realized I had my measurements backwards (question still remains the same). Instead of being just a little over 1 1/16 it is just under.

I think I will try the suggestion of grinding down a 1-1/8" bit. Could be fun even. (It probably took a machinist to think of that one (Thanks JayJay)). I've tried the hole saw, but it was a little big.


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## GaryC (Dec 31, 2008)

You can buy 1 1/8 auger bits.


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## Westy (Nov 16, 2009)

The OD for 3/4" pipe is 1.050 which is less than 1 1/16" (1.062), so the 1 1/16 dia should work.


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## unisaw2 (Feb 2, 2010)

MLCS has a forstner bit that is 1-1/16" that I used to install rigid electric pipe. They are around $7 each and cut very clean holes. They have a good selection of sizes. (1-1/32" etc)
http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/forsbit.htm


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