Workbench - bench dog holes

[Don Stutsman]

I have an old but very useful laminated beech workbench top. It has plenty of holes for bench dogs -but - all the holes are 9/16" dia.and most (all that I can find) bench dogs are 3/4" dia. or square. I would like to redrill the holes and would like some opimions on how to go about it to ensure the holes are accurate and squate in the top. Drill press is out since the top is too large and heavy. Any ideas?

[George Bregar]

I have an old but very useful laminated beech workbench top. It has plenty of holes for bench dogs -but - all the holes are 9/16" dia.and most (all that I can find) bench dogs are 3/4" dia. or square. I would like to redrill the holes and would like some opimions on how to go about it to ensure the holes are accurate and squate in the top. Drill press is out since the top is too large and heavy. Any ideas?

First thought would be to plug the holes with 9/16" dowels. This will give the center spur of a spade bit material to keep the bit centered. Then still use the drill press, just have the top supported by some sawhorses on the ends to carry the weight, using the DP bed to insure that the 3/4" hole is perpendicular.

[Tom Veatch]

I have an old but very useful laminated beech workbench top. It has plenty of holes for bench dogs -but - all the holes are 9/16" dia.and most (all that I can find) bench dogs are 3/4" dia. or square. I would like to redrill the holes and would like some opimions on how to go about it to ensure the holes are accurate and squate in the top. Drill press is out since the top is too large and heavy. Any ideas?

1) drill a 1/4" hole through the center of a 9/16 dowel, use that in the existing hole to center and guide a 3/4 hole saw. Once the hole is started follow with a 3/4 forstner or auger.

or

2) plug the hole with a dowel and re-bore with a 3/4 ship auger centered on the dowel. Use a DP to drill a 3/4 hole through a squared block and use that to guide the auger.

or

3) drill a 3/4 hole through a block, position and clamp the block centered over the existing hole, use it to guide a hole saw, forstner, or ship auger

or

...

[Gary Keedwell]

Plunge router and 3/4" center cut router bit?
Gary

[keith ouellette]

I have to go with the plunge router idea also. Stable, straight, clean, no wiggling and dust collection. It's got it all but you may need a long bit. $$$

[Charles Wiggins]

Don,

Playing off Gary & Keith's idea, you might be able to adapt the method that Glen Huey demonstrates in this video (http://fw_woodworking.permissiontv.c...?showid=474515), if you could rig a way to center over each hole before you start.

[Tom Veatch]

...you may need a long bit. $$$

Or a long plunge depending on the thickness of the top. I know mine doesn't have enough plunge depth to penetrate the top of my bench. Could start the hole, and either extend the bit or replace with a longer bit and continue. How about plunge as deep as it will go, and if it doesn't completely penetrate, use the partially through hole as the guide for a through drill/bore.

Hmmm. Just saw the video. Looks like Glen Huey beat me to the idea.

[Gary Keedwell]

1) drill a 1/4" hole through the center of a 9/16 dowel, use that in the existing hole to center and guide a 3/4 hole saw. Once the hole is started follow with a 3/4 forstner or auger.

or

2) plug the hole with a dowel and re-bore with a 3/4 ship auger centered on the dowel. Use a DP to drill a 3/4 hole through a squared block and use that to guide the auger.

or

3) drill a 3/4 hole through a block, position and clamp the block centered over the existing hole, use it to guide a hole saw, forstner, or ship auger

or

...

Sounds like alot of work to me But on the other hand, it is always fun to try new stuff. :>)
Gary

[Larry Laffer]

Lots of ways to do that, as others have pointed out. All I would add is that you should definitely use a jig to make sure all the holes line up. Or, you could make your own dogs from wood or for more strength, get a brass rod and saw off a bunch of em. Cut notches in the top, and face the flat surfaces with leather, plastic, etc to suit your needs. Bore a small hole in the side of each dog and insert bullet catches (I think that's what they're called) so they stay put.

[Tom Veatch]

Sounds like alot of work to me
Gary

Yeah, I like the plunge router idea much better. Wish I'd thought of it.

Expanding on that, if the new holes absolutely positively have to be concentric with the old holes, use the positioning tool/template in the video, but center the router first, then use the router to position the template.

How to center the router? How about using something chucked in the router that is the same diameter as the existing hole - a 9/16 straight router bit? or a 9/16 drill bit with a 1/2" shank - that would center the router over the hole. Then a 3/4 plunge bit would bore the new hole concentric with the old hole. Still have to swap bits between holes so that's a little more labor intensive that optimal.

If there is some tolerence on the concentricity of the new hole, instead of a template like in the video, attach and oversized piece of hardboard, etc, to the router baseplate and plunge through the hardboard to get a 3/4 hole (like a zero clearance insert). Center the baseplate hole over the existing hole by eyeball, clamp it, and plunge. Less labor intensive, but not as accurate.

[Chris Schoolland]

A unibit will dial you right up to the hole size you need. A 6x6 block of wood drilled on the DP could be the plumb guide for a longer bit in a regular drill, but only if that sexy router idea can't get you deep enough.

[Jim Becker]

When I accidentally "misplaced" some dog holes on my bench, I just plugged them with dowels, sanded them flush and redrilled the holes in the correct location.

[Doug Shepard]

If you can find a 3/4" core-box (round-nose) bit I think it would self center in the smaller hole to get the plunge going.

[john bateman]

There are reduced shank drill bits. If the current holes are in the right place and straight, just follow through using a hand drill and one of these.


http://doitbest.com/Hole+Saws-Mibro+...sku-334926.dib

[Gary Keedwell]

There are reduced shank drill bits. If the current holes are in the right place and straight, just follow through using a hand drill and one of these.


http://doitbest.com/Hole+Saws-Mibro+...sku-334926.dib

That might be a little more then your wrists might want to experience. A two flute that size will want to catch and take your wrist with it.A router and a simple jig for positioning would be my path. IMNSHO
Gary