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Joined: Nov 2000
Posts: 2,236
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I've got to put a piece of 1/2" PVC through a porcelain brick wall. Having installed a few anchors in it, I've learned that the brick tends to eat up normal carbide tipped masonry bits rather quickly. What method and/or type of bit for do I need for this?

I'm thinking... Run drill on known working GFCI circuit, while running water on bit to keep it cool, no hammer action (will probably crack the brick) and go real slow.

A diamond tip bit would be good, but I doubt I have the resources to aquire one.

Any ideas?

[Linked Image]


-Virgil
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Water and carbide are not a good mix. The water tends to shock cool the bits and that tends to crack the carbide. If you can keep the water on consistantly its not a problem, but if the bit warms up and gets cooled it will shatter the tip.

Try a glass cutting drill bit. Porcelain is closer to glass than it is ceramic in terms of it's drilling properties. The bits are fairly inexpensive, and you will eat them up as well, but they may work better depending on the type of porcelain.

[This message has been edited by Joule-E (edited 08-31-2002).]

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I've core drilled with water before, what's the difference, besides it being hardened concrete rather than porcelain?

Glass cutting drill bit, eh? Being WV, I should be able to find that... (Glass used to be one of our biggest exports). Do they make 'em as big as 1-1/8"? (1/2" PVC Male Adapter and end of 1/2" PVC LB will have to fit into the hole to make it pretty).


-Virgil
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66wv — Hypothetic’ly, say you could only find a 7/8-inch drill. {Milwaukee used to advertise hole saws that were claimed good for ceramic tile.}

OK, this is an utterly insane suggestion—but there used to be a perennially cigar-chewing pump/dairy-barn/plumbing/veterinary/sort-of-electrical/daycare shop owner that was so cheap he would require his helper to run brittle schedule-40&80 PVC waterpipe through an electric threader, saving the $1.80 for an [up to 2½-inch] cement-on threaded adapter. {I never found out what his payscale was.}

Way off topic—but even weirder—he would buy many reels of 4/0 Cu THW, and never bat an eyelash putting in 300-foot UG runs to settling-pond manure pumps. "But it's 480 you idiot! It dun't matter!" was his explanation of never adding that extry "useless" ground warr with his fat-copper, plastic-water-pipe circuits. [He was also good for putting in 2-pole along side single-pole jab-in circuit breakers in 240V∆ panelboards for 3ø motors, sans so much as a tiebar nail.]




[This message has been edited by Bjarney (edited 08-31-2002).]

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Sorry to get back so late. Porcelain is much denser than concrete and maintains a greater degree of contact with the drill tip resulting in a hotter piece of carbide in a shorter amount of time. Using a hammer drill on the porcelain will not be as effective as using one on concrete bcause of the difficulty in chiseling porcelain (or glass).

Concrete has more voids and air allowing the hammering action to crush the spaces and cut the material away uch easier.

Ceramic brick (the dense kind, not the cheap flakey stuff) cause the same problem. Clay and glass are all vitrified and denser (most of the time) than concrete ans make drill bits hotter. If you can drill straight down and keep water on the bit at all times, you wont run into any problems, but if you drill on a wall and cool the bit intermitantly it can crack it from the sudden change in temperature.

Thats a bigger hole than I thought you were talking about, and I would guess you could get that big a glass cutting bit. Good luck

Joined: Nov 2000
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Joule-E,

Thanks for the heads-up... I think I'll just buy a few more LB's and poke it through the soffit instead...

It'll be a tight attic trip, through...
...with bees!

[Linked Image]


-Virgil
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Here's what I've done many times - buy those glass/tile bits...but in 1/8" - 1/4" diameter...they cut Real fast...drill a number of holes in a circular pattern for the larger diameter you need (I've done this for 4" diameter)....once you have your numerous small holes cut you can easily knock out the center section with a hammer, chisel...yes you have a ragged hole...that's what caulk, etc. is for...to keep the conduit off the ragged edges and patch up the hole nice and clean.

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OOOHHH I like it Dana1028, thats a great idea,

Joined: Apr 2001
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J
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Been there, done that. Get a set of glass-cutting bits (to 1/4"). Drill a series of holes around the perimeter of where you want the hole to be, working your way up from size to size. Then, punch out the center.


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