How do you make plumb vertical holes, i.e. dog holes in a 4" thick bench top?

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Forum topic by crank49 posted 04-16-2011 11:15 AM 8019 views 1 time favorited 14 replies Add to Favorites Watch
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4032 posts in 3205 days

04-16-2011 11:15 AM

I was wondering if there are better ways to make accurate holes, like dog holes for a bench top, than what I am doing. I am just using a slow speed, high torque 1/2” corded portable drill with a double land 3/4” brad point bit. I am aligning this by eye and locating the holes relative to each other with a jig (a board) with two holes the required distance apart and dropping a dowel pin through the jig and into the hole I just drilled.

I have read where some folks make these type holes with a plunge router. What type of bit? I have to drill through a 4” thick bench top; never saw a router bit that could do this.

In steel I would use a portable magnetic drill press with a slugger bit. Those things are around $1000 and up. Anything similar out there for woodworkers? At a reasonable cost? Can’t pay $1000 for this.

14 replies so far

View SergioC's profile


82 posts in 2902 days

#1 posted 04-16-2011 11:21 AM

I wouldn’t use a plunge router, but if you did, you only need to start the hole very accurately. Once it is deep enough, the started hole will guide your drill. Not sure if you have a drill press but I would drill about a 1” board or thicker or melamine and use that as a drill guide.

View bubinga's profile


861 posts in 2902 days

#2 posted 04-16-2011 11:54 AM

I used a forstner bit and ,a drill guide attached to portable drill. if you want it rock solid ,attache the bottom of guide,to a board ,drill hole through the board ,and clamp the board to bench. and you can attach a fence to bottom of board, for same distance,from edge along bench
Center punch for holes first

-- E J ------- Always Keep a Firm Grip on Your Tool

View HorizontalMike's profile


7770 posts in 3148 days

#3 posted 04-16-2011 02:07 PM

Here you go Crank,
The Brad point bit with drill is the way to go.

Similar to Barry’s I’m sure, this is the template I used to drill all the dog holes in my 21st Century Workbench. I used scrap piece of 2” Ash and glued a 90d. fence on it for edge referencing. I also used a 1/2” hammer drill set to drill mode. NOTE—Do NOT forget to use a back plate to stop tear out on the exit side.

-- HorizontalMike -- "Woodpeckers understand..."

View Loren's profile


10477 posts in 3882 days

#4 posted 04-16-2011 07:57 PM

I made a jig to drill these holes once.

I made a 4-sided box of plywood I could just jam my drill into. I fitted
the sleeve so the drill was aligned.

Then I made a second sleeve the drill sleeve could slide in. A piston,
if you will. Then drilling the holes was easy.

I got the idea from a similar idea in a magazine article. It might have
been Michael Fortune’s wood-bending system.

View hokieman's profile


192 posts in 3988 days

#5 posted 04-16-2011 10:21 PM

I did mine the same as Bubinga. Worked fine.

View bubinga's profile


861 posts in 2902 days

#6 posted 04-17-2011 05:39 AM

A Brad point bit would be much better, I used what I had
I have used the guide block method for tapping threads ,straight , works great

-- E J ------- Always Keep a Firm Grip on Your Tool

View WayneC's profile


13794 posts in 4332 days

#7 posted 04-17-2011 06:30 AM

Found one on Amazon…. Not cheap

-- We must guard our enthusiasm as we would our life - James Krenov

View bubinga's profile


861 posts in 2902 days

#8 posted 04-17-2011 06:39 AM

Maybe you could rent a tripod drill for a few hours
Cheaper General Tool 36/37 Accu Precision Drill Guide

-- E J ------- Always Keep a Firm Grip on Your Tool

View LyallAndSons's profile


66 posts in 2831 days

#9 posted 04-18-2011 07:44 AM

FWIW you may want to angle the dog holes a bit if they are the ones in line with an end vice. My first bench had them @ a 90 degree angle to the top and, if the dogs weren’t deep, they sometimes tried to creep out a bit after the bench got a little wear. For example, If the stock is clamped tightly between the end vice and a dog and I began to hammer on it. I noticed it when cleaning up mortices with a chisel and mallet.

I made the holes in my new bench @ a 4 degree angle and they are rock solid. The old bench had alot of use before that began to happen but that was the main reason I built the one I use now.

-- Lyall & Sons Woodsmiths...Custom handcrafted woodwork since 1989

View Richard's profile


1922 posts in 2925 days

#10 posted 04-18-2011 09:59 PM

Deke and bubinga , have you had good luck with those drill giudes? I bought one at Sears and it had so much slop in the chuck that the bit looked like a mixer going side to side so much. I took it back and checked 3 more on the shelf and they all had the same slop in them. I wish I could find another one of the old Portaline units I had a long time ago, it was dead on and no slop.

View bubinga's profile


861 posts in 2902 days

#11 posted 04-19-2011 02:19 AM

I don’t even know what brand the one I have is, but there is no slop, I bought it , about a million years ago
I used it a lot before I got a drill press, I would have to look at it to find a brand name.
Here is one of three I found at Amazon—-
here is a Portalign Drill Guide for $11

Well !! I saw a picture of the Portalign Drill Guide , so I guess that’s what I have because mine is exactly the same. I saw one in a Craigs list they were asking $125 for it. HAA

-- E J ------- Always Keep a Firm Grip on Your Tool

View Jim Bertelson's profile

Jim Bertelson

4256 posts in 3399 days

#12 posted 04-19-2011 02:50 AM

This may or may not be pertinent, but…......whatever device you use to make it perpendicular, I think that is the biggest issue…......for bits, this might work…........

.........I found I could start the hole with a Forstner bit, so the hole top is really clean, and then finish the hole with a first class spade bit, like the new Irwins. That speeds up the job immensely, those Forstner’s are really slow with a hand drill.

-- Jim, Anchorage Alaska

View crank49's profile


4032 posts in 3205 days

#13 posted 04-21-2011 02:40 AM

Thanks for all the suggestions.

I have one of the $50 drill guides, I’ll give it to anyone who wants to pay the shipping. Every time I try to use it I get more angry that I paid that price for such a POS. Should help to screw it down to a board. Maybe I’ll try that before I give it away; or pitch it in the creek.

I found forstner bits wander too much in a handheld drill. The double land, brad point “Colt” bits at Woodcraft are the best I have tried so far. It goes exactly where you point it; no wandering off. Now if I could only I could point it in a true vertical line. The tripod drill looks like a fine idea.

Horizontalmike, that guide block drilled in the drill press is how I have done most of the holes I have done so far, but I was using a piece of very old yellow pine heart wood as guide material; too soft, but made the shop smell real good.. Maybe I’ll get some hardwood and try again.

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