# Help me drill a hole **URL:** \ **Category:** In My Humble Opinion\ **Created:** [February 11, 2021, 4:41pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698 "2021-02-11T16:41:21Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 11, 2021, 4:41pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/1 "2021-02-11T16:41:21Z")
Let me say at the outset, that I am a handyman’s handyman. I have a very well-equipped shop, and a lot of experience at home repair. That said, I’m having problems trying to figure out the best way to do this: I want to drill a 1 14" hole in a “Quartz” countertop. I have the diamond-edged hole saw to do it. Simple, right? The problem is, I want the hole to line up with an existing hole in the metal flange of an undermount sink. The obvious solution is to drill the Quartz from the bottom, using the hole in the sink as a guide. But - the diamond saw blade is supposed to be immersed in water. So, how do I do this? I was thinking that I could maybe use a small-diameter bit to drill a center hole from the bottom, but I think that the likelihood of getting it both perfectly centered and straight is slim. I could use the hole saw from the bottom, and go very slow, and stop and spray it will water every few seconds, but that sounds terribly messy and slow. Any other bright ideas? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [February 11, 2021, 4:43pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/2 "2021-02-11T16:43:31Z")
Use a pre-measured jig to assure alignment? Stranger ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [February 11, 2021, 4:46pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/3 "2021-02-11T16:46:43Z")
Does the hole saw have a center ‘drill bit ?’ Can you use that to drill a pilot hole through the bottom, and then drill out the 1.25"d hole from the top ? Are the clearances in 000ths or are they really more like tenths ? ETA: I really didn’t read your OP well enough. Apologies. A bit distracted 😉 ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 11, 2021, 4:46pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/4 "2021-02-11T16:46:54Z")
Everything is installed. So, I don’t think I can get an accurate measurement, because I can’t access the top and the bottom at the same time. The sink is in the way, preventing me from taking an accurate measurement of the hole position from the bottom. I’ll have to ponder it and see if there is a way to get a reference point that is accurate from both the top and the bottom. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 11, 2021, 4:48pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/5 "2021-02-11T16:48:48Z")
No, this hole saw has no center bit. But… I could make a thick washer that would act as a guide. It’s a good suggestion. ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [February 11, 2021, 4:50pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/6 "2021-02-11T16:50:43Z")
Ever used a transfer punch ? Apparently, they come in 1-1/4" d, too ! > **[TTC 1-1/4" Individual Transfer Punch (Spotter) - Hand Tool Transfer Punches -...](https://www.amazon.com/TTC-Individual-Transfer-Punch-Spotter/dp/B00AN97GMS)** > > TTC 1-1/4" Individual Transfer Punch (Spotter) - Hand Tool Transfer Punches - Amazon.com ---
**Author:** ![filmore](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@filmore](https://boards.straightdope.com/u/filmore)\ **Post date:** [February 11, 2021, 4:58pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/7 "2021-02-11T16:58:09Z")
What about putting a really strong magnet in the hole on the bottom and then sprinkling iron filings on the top of the counter? The iron filings might line up with the magnet and show where the center of the hole should be. Or use another magnet on top and see if you can feel the magnet field yourself. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 11, 2021, 5:00pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/8 "2021-02-11T17:00:16Z")
That’s a clever idea, but the countertop is pretty thick - like 3/4". ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [February 11, 2021, 5:07pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/9 "2021-02-11T17:07:28Z")
The kettle is done whistling. The French Press coffee is done brewing. I can focus now 😉 ISTM that your issue will be in maintaining a pretty perfect right angle _to_ your sink flange and the countertop – no easy feat. When I drilled “dog holes” in the ‘countertop’ of the shop-made work bench for my woodworking shop, I bought a right angle jig meant for such tasks. For example: [https://www.amazon.com/Milescraft-1318-DrillMate-Drill-Guide/dp/B014A1Z92I/](https://www.amazon.com/Milescraft-1318-DrillMate-Drill-Guide/dp/B014A1Z92I/) Absent such a jig, or comparable strategy, your starting hole could be perfect but you could end up a good half-hour away from your desired endpoint if you weren’t either lucky or good. And working upside down in cramped quarters ? I’d get a price from a countertop installer … and I’m dumb enough to try just about **anything** once 😉 ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [February 11, 2021, 5:12pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/10 "2021-02-11T17:12:47Z")
Going on a bit … Even a straight (ie, made with a forstner bit on a drill press) hole in a good piece of thick-enough hardwood can make for a good erstwhile right angle template **if** you can clamp it solidly in place and center it well. But … again … given what I presume are your circumstances … probably easier said than done. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 11, 2021, 5:21pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/11 "2021-02-11T17:21:15Z")
Yeah, I’m leaning that direction… Making a custom metal guide - maybe a 1" tall cylinder, 1 1/4" in diameter, which I can hold in the existing hole in the flange from the bottom, and use it to drill a guide hole with a masonry bit (Quartz drills really easily). Then, take it to the top side, use the bit to center the guide, and then trace around the edge. Then use a that marking to center a drill guide, and drill away. The hole location only needs to be accurate to 1/8" or so. ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [February 11, 2021, 5:21pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/12 "2021-02-11T17:21:24Z")
One more 😉 There does seem to be a 1-1/4" diamond-edged hole saw _with_ an arbor that is quite likely easier to steer without a jig than one without an arbor: > **[Amazon.com: DG HOLESAW 20DG 1 1/4 31.8MM 1/PK : Everything Else](https://www.amazon.com/DG-HOLESAW-20DG-31-8MM-PK/dp/B002QMP546)** > > Amazon.com: DG HOLESAW 20DG 1 1/4 31.8MM 1/PK : Everything Else [arbor sold separately but referenced in the " Frequently bought together" area. No idea if the arbor, bought on its own, would work with your existing hole saw. ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [February 11, 2021, 5:24pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/13 "2021-02-11T17:24:23Z")
> [@beowulff](#): > > Making a custom metal guide - maybe a 1" tall cylinder, 1 1/4" in diameter, which I can hold in the existing hole in the flange from the bottom, and use it to drill a guide hole with a masonry bit (Quartz drills really easily). How will you center the (presumably much smaller dia than 1.25") bit ? Now you’re probably talking about a fender washer that fits snugly into your ‘shop-made funnel’ guide. And what will keep you from twisting the drill off-axis while you’re drilling ? The lip of that metal cylinder ? Might need to be lucky there, too 😉 ---
**Author:** ![filmore](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@filmore](https://boards.straightdope.com/u/filmore)\ **Post date:** [February 11, 2021, 5:24pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/14 "2021-02-11T17:24:46Z")
If you happen to have any scrap from the countertop install, you could test out a few methods on the scrap to see what works best. I would guess the countertop installers would have scrap you could get cheap as well. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 11, 2021, 5:36pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/15 "2021-02-11T17:36:51Z")
Think of a 1" thick fender washer. Basically, a cylinder that fits snugly into the hole in the sink, and has a guide hole drilled down the center. ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [February 11, 2021, 5:40pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/16 "2021-02-11T17:40:36Z")
Can you “mount” the sink upside down on top of the counter? I can’t think of a reason that the sink can’t move a little in any direction? ---
**Author:** ![DavidNRockies](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidnrockies/32/6279_2.png) [@DavidNRockies](https://boards.straightdope.com/u/DavidNRockies)\ **Post date:** [February 11, 2021, 5:42pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/17 "2021-02-11T17:42:37Z")
Ohhhhhhh. You’re just talking about a slice of 1-1/4" round bar, [![](https://i.ebayimg.com/images/g/0AoAAOSw6gpe6lxt/s-l1600.jpg) ](https://i.ebayimg.com/images/g/0AoAAOSw6gpe6lxt/s-l1600.jpg) Cut dead square at the ends and drilled (still not a no-brainer, but definitely doable) in the dead center to guide your masonry bit. The puck has to sit fairly firmly in your undermount flange (hot glue ? lucky friction fit ?) so as not to move/rock. You still have to do a good job of keeping the drill perpendicular to the puck _and_ the flange/countertop, but … It could work. And you would be a magnificent bastard if it did. Take video 🙂 ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [February 11, 2021, 5:45pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/18 "2021-02-11T17:45:25Z")
If this is for a faucet, can’t you just drill through the metal a little. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 11, 2021, 5:46pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/19 "2021-02-11T17:46:22Z")
LOL. Right now, the pressure is off of me to do this, but if I comes up again, I’ll be sure to post my solution. This is for a garbage disposer pressure switch. I’m currently using a top-mounted radio-controlled switch, which has been working fine, but recently decided to fail. I went out and bought the standard air-pressure switch to replace it, but it decided to start working again. If it fails in the future, I’ll replace it. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [February 11, 2021, 5:58pm UTC](https://boards.straightdope.com/t/help-me-drill-a-hole/932698/20 "2021-02-11T17:58:33Z")
Any kind of round plug with a hole in the center can be used to drill a pilot hole so you can drill from the top. Even then you should start drilling the main hole slightly undersized and use the right size hole saw or grinder to get the final alignment with the flange. Finally, you don’t need water. It’s actually more efficient to cut without it as long as you keep cooling the bit off manually with a spray bottle or dunking it. There will be a lot of extra dust, but the bit will actually cut faster when dry. [Next page](https://boards.straightdope.com/t/help-me-drill-a-hole/932698.md?page=2)