Drilling Dog Holes

There are a couple or three schools of thought when dealing with dog holes in a bench top. One is the "Swiss Cheese" approach, another is "only as needed, where needed". While I've never gone full Swiss Cheese I have done the only as needed where needed and the biggest problem with that approach is stopping in the heat of battle to drill a dog hole. I would end up doing a work around thinking I would do it later, of course "later" seldom happens.

My approach lately is not full Swiss Cheese but more than just where needed by making two rows of dog holes on both edges for the bench. With a sized jig that has two guide holes it is fairly quick and easier work than marking and free handing.

Attachment 415367

Once the first hole is drilled put a dog in the jig's first hole and then dill using the second hole, repeating until finished.

Attachment 415368

ken

Two rows 4" apart for me. The first is only 3/4" from the front as I do a lot of beading work. Probably Swiss cheese for some, but mine is the 3rd and final bench and have never regretted the dog hole placement.

Ken, that sure is a beautiful bench!

On my bench, I went with the "only as needed, where needed" approach. How did you prevent blowout/tearout on the bottom side of the benchtop, as your drill exited the new hole? (I made a mess on the bottom of mine - I couldnt place a backing board effectively. "Fortunately" my benchtop is SYP dimensioned lumber, but it still hacked me off.)

Fred

PS. In case it helps someone, I used a Jig-It Drill Guide from Rockler (LINK) along with a long forstner.

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Originally Posted by Frederick Skelly

Ken, that sure is a beautiful bench!

On my bench, I went with the "only as needed, where needed" approach. How did you prevent blowout/tearout on the bottom side of the benchtop, as your drill exited the new hole? (I made a mess on the bottom of mine - I couldnt place a backing board effectively. "Fortunately" my benchtop is SYP dimensioned lumber, but it still hacked me off.)

Fred

PS. In case it helps someone, I used a Jig-It Drill Guide from Rockler (LINK) along with a long forstner.

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Thanks Fred,

From what little I've worked on it I believe it will be a good one for a smaller space.

That is one of the reasons I was hesitant to drill dog holes, most everyone has their preference to placement and number and I plan to sell/give away this bench in the future to make room for the bench in my head. But bottom line a bench isn't much good without dog holes to help hold work so I drilled away. I got a little tear out on a couple of holes kinda for the same reason, difficulty in holding a backer board. What I've found is with a sharp drill if you clean the waste out when you get to 1/4-1/2" from the bottom then just let the drill run with no pressure it will usually make a clean exit. It doesn't always work but will most of the time, see the tearout on a couple of holes :p.

ken

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With a sized jig that has two guide holes it is fairly quick and easier work than marking and free handing.

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Thanks for the great Idea Ken. This has me thinking about making a similar helper with three holes so the holes along the sides of the bench will be spaced equally for my bench top planing stops:

Attachment 415375

There are a few extra holes for using dogs with a single bench stop to hold the far edge of the board from moving.

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How did you prevent blowout/tearout on the bottom side of the benchtop, as your drill exited the new hole?

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My dog holes are done the old fashioned way, with an auger bit and a brace. When it gets close to the underside a corner brace is used from the underside:

Attachment 415376

To finish the boring the corner brace has the ratchet set and the bit is started in the lead hole by turning the chuck by hand. A clean hole every time.

My bench doesn't look quite like Swiss cheese, but it does have extra holes bored for specific needs. One would be for a bench claw made after seeing one on The WoodWright's Shop with Roy Underhill:

Attachment 415377

This is very handy when planing a lot of edges. Much quicker changing work pieces than using a vise.

jtk

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Originally Posted by Jim Koepke

Thanks for the great Idea Ken. This has me thinking about making a similar helper with three holes so the holes along the sides of the bench will be spaced equally for my bench top planing stops:



There are a few extra holes for using dogs with a single bench stop to hold the far edge of the board from moving.



My dog holes are done the old fashioned way, with an auger bit and a brace. When it gets close to the underside a corner brace is used from the underside:



To finish the boring the corner brace has the ratchet set and the bit is started in the lead hole by turning the chuck by hand. A clean hole every time.

My bench doesn't look quite like Swiss cheese, but it does have extra holes bored for specific needs. One would be for a bench claw made after seeing one on The WoodWright's Shop with Roy Underhill:



This is very handy when planing a lot of edges. Much quicker changing work pieces than using a vise.

jtk

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Jim,

You are the man, my arm would take a week or so to recover if I use the brace and with Tucson's temps this Summer it could take even longer to finish :).

All you need are two holes in the jig once the first bench dog hole is drilled just drop a dog in it, set the back jig hole over the dog, line up the jig (I sized the jig so the edge lined up with the edge of the slab), drill using the second hole, repeat as needed.

I'm with you on using other means of holding when able.

ken

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All you need are two holes in the jig once the first bench dog hole is drilled just drop a dog in it, set the back jig hole over the dog, line up the jig (I sized the jig so the edge lined up with the edge of the slab), drill using the second hole, repeat as needed.

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My thought was to have extra hole(s) for drilling the second row of holes along the far side at the same time to keep the holes aligned in two directions.

jtk

That’s a good approach. I’ve found it’s no problem to drill the odd hole for a bench hook sometimes you need a bench hook in a different location.

When I built my last bench about 10 years ago I started with an electric drill and an expensive German 3/4" brad point bit. My bench top is 3" thick white Ash. It was really slow going and after 3 holes I gave up and changed to my widest swing brace and a 3/4" Russell Jennings auger bit with the fine tip lead screw. It was far quicker and the hole quality was better.

I expected you to use a router... Looks like a nice / smart method.

Mine are about 4" apart, only 1 rows goes very far, the other two "rows" only have 2 holes...

12 or 14" sweep braces, 13/16" bit....

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Originally Posted by steven c newman

Mine are about 4" apart, only 1 rows goes very far, the other two "rows" only have 2 holes...

12 or 14" sweep braces, 13/16" bit....

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Do you know how well do the Veritas 20mm parts fit into a hole drilled with the 13/16" auger? I've got the opportunity to buy a 13/16" vintage Sheffield (new in box) but wonder if I should go for a 20mm Forstner instead. When I look at the OEM details for FMT/3 I notice they've specified 20.2mm holes. Decisions, decisions....

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Originally Posted by Marinus Loewensteijn

Do you know how well do the Veritas 20mm parts fit into a hole drilled with the 13/16" auger? I've got the opportunity to buy a 13/16" vintage Sheffield (new in box) but wonder if I should go for a 20mm Forstner instead. When I look at the OEM details for FMT/3 I notice they've specified 20.2mm holes. Decisions, decisions....

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By way of conversion 13/16" is equal to 20.6375mm. Auger bits are usually in the range of 0.015" larger than their marked size unless they are made specifically for dowelling use.

My Sjoberg bench came with 18mm dog holes. When adding dog holes my 3/4" bit is used. It works fine with the holdfasts Harry Strasil made with a 5/8" rod diameter.

The 18mm and 3/4" holes also work with my Veritas® Surface Clamps though they aren't used since buying the holdfasts.

My question is why do the folks who use metric tend to use 18mm or 20mm in place of 3/4" when 3/4" is almost exactly 19mm?

jtk

I use wooden dowels for the dogs. I buy 7/8" sized dowels, and taper those to fit.

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Originally Posted by steven c newman

I use wooden dowels for the dogs. I buy 7/8" sized dowels, and taper those to fit.

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You could likely take one of the holes with you to the store and find a dowel to fit without modification. :D

Mine are made on a lathe:

https://sawmillcreek.org/showthread.php?207672

A 3/4" open end wrench is used as a size gauge.

There are other posts in the thread with other methods of making round dogs.

jtk

I don't have a lathe. taper was by beltsander, set upside down in a vise ( by the top handle) and then the taper was done right behind the front wheel. Spin it a bit, check the fit, spin and sand where needed...Dogs were too short to use a spokeshave on...

Brace used was a PS&W 8012, Samson chucked brace...12" sweep...set a square alongside the bit....and drill a straight hole. wasn't worried about any "blow-out" under the top..
Attachment 415599
Ones in the jaws are only 1" or so long, holes are a tad deeper.

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Originally Posted by Jim Koepke

By way of conversion 13/16" is equal to 20.6375mm. Auger bits are usually in the range of 0.015" larger than their marked size unless they are made specifically for dowelling use.

My Sjoberg bench came with 18mm dog holes. When adding dog holes my 3/4" bit is used. It works fine with the holdfasts Harry Strasil made with a 5/8" rod diameter.

The 18mm and 3/4" holes also work with my Veritas® Surface Clamps though they aren't used since buying the holdfasts.

My question is why do the folks who use metric tend to use 18mm or 20mm in place of 3/4" when 3/4" is almost exactly 19mm?

jtk

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Thanks for the remark that an auger bit normally is slightly larger than the stated size.

Holdfasts need a larger hole to work properly - too small and they tend to slip. As such I am not surprised that 5/8" works fine in 18mm holes.

I am going to try the 20mm Forstener first and if it does prove to be too tight then I'll just make a template from some delrin sheet and use the router with a flush trim bit.

To answer your question: In our country of just under 5 million people we can get Festool FMT/3 gear but 3/4" stuff is not standard available. And I found on ePray some Veritas 20mm surface clamps in open box with a substantial discount.