Square dog hole apron process

[Ned Otter]

Having read a gazillion posts on workbenches, dogs, vices, etc, everything I've seen about creating square dog holes describes routing the holes in an apron strip, and gluing that "layer" along with others to the bench.

Why not simply cut and glue pieces of wood with the proper grain orientation to the apron at intervals of "square dog hole" width, and when dried, glue that entire assembly to the bench?

Thanks in advance --

Ned

[David Carroll]

I'm not sure of the answer here, but I can think of 2 reasons.

1. The forces applied by a screw are pretty big, I don't know the math, but I would imagine it would be measured in hundreds of pounds if not tons. That's a lot to ask of an un-buttressed glue joint, or more accurately, the wood fibers next to the glue joint, which could shear off or pull out. Glue joints are generally stronger than the wood itself, but in my experience the joint fails right next to the glue line. Over time I would imagine the blocks could creep enough to make inserting the dogs either really sloppy or really tight.

2. Gluing up would be a nightmare, keeping all of the blocks, in position while clamping the assembly would be a challenge, you would almost have to make dog blocks to fit in the spaces where the dogs will insert and clamp from the ends.

Of course both problems could be overcome, but the traditional approach of cutting a series of dadoes in the skirting board and then gluing it to the top, only requires one board, twice as thick as the rest and is a relatively straight forward process.

JMHO, I've made two benches with the rectangular dog holes, made the traditional way, and while doing so, thought through your question, it occurred to me as well. But went the other way for the reasons noted.

DC

[Jim Koepke]

As David said, it may cause a weakness where strength is preferred.

To me it would seem faster to make a simple guide for routing with a built in spacing mechanism than it would be to glue everything. It could even be less work to cut it out by hand with saws, chisels and other means of removing the waste.

Also part of the reason for having a row of dog holes along the front edge of a bench is to hold things at the edge for working. A thin apron would negate the possibility of using holdfasts and possibly other bench furniture along the front of the bench.

With an apron of a useful thickness this would place the dog holes further from the edge. This could affect the use of fenced planes on some work.

Just my 516321

jtk

[Ned Otter]

Thanks to all who have replied -- Jim, to be clear I'm not talking about having a thin apron, total thickness of what gets glued to the existing bench will be 2-5/8".

Will think on it some more, and figure out what to do.

Thanks,

Ned

[Kent A Bathurst]

Having read a gazillion posts on workbenches, dogs, vices, etc, everything I've seen about creating square dog holes describes routing the holes in an apron strip, and gluing that "layer" along with others to the bench.

Why not simply cut and glue pieces of wood with the proper grain orientation to the apron at intervals of "square dog hole" width, and when dried, glue that entire assembly to the bench?

Thanks in advance --

Ned

This is exactly what I did. I included a slight angle/cant to the spacer blocks to allow for the dog to go to vertical under pressure, because I taped a .030 shim [hotel keycard] to one side of the dog, and used that assembly to position each of the spacers. Tail vise block done the same way. I had the same concern as David's #2, so I did one dog hole spacer at a time.

I had a special reason for using this approach - Red oak with walnut dog hole spacers. Walnut was a family semi-treasure: Salvaged from flooded Kansas farm bottomland by Dad and his FIL. Used it for the under-bench cabinet drawer fronts as well.

30 years old and counting. Zero problems/failures.

[Ned Otter]

Thanks, Kent - what you described is exactly what I had in mind - one dog spacer at a time. Glad to know that it has held up well for decades.

Might you have a photo of this semi-treasure workbench of yours?

Best,

Ned

[Kent A Bathurst]

Yep. I gotta get there first. Later today

[Kent A Bathurst]

Might you have a photo of this semi-treasure workbench of yours?

File under: Be careful what you ask for. I view the bench as a tool. It has drill holes, blade scars, everything. No apologies, but no bragging either. Not in same class as all the other benches seen here, but...has served me well.

The absolute very first solid-wood thing I ever made was my bench. Neighbor was doing rehab on a house built 1880's, down to the studs. It was framed in red oak. He tore out a section of roof. I scarfed up the wood. Maybe 40% yield gave enough for the bench top except for the outer rim boards, which were new. You can tell the difference in the first photo.

The dog hole spacers are Kansas walnut. Notice the dog on the bench - the holes are notched to receive the brass face. I don't remember where I got the dogs, but hadda be some well-known place, because I didn't know squat. Coulda been LL Johnson in Charlotte, MI. As mentioned, the hole spacers have an angle/cant to them - 7% sticks in my mind, but no guarantees. I stood in LL Johnson's showroom many Saturdays reading every reference book on building a bench, so that % musta come from one of those.

Cabinet is RO 3/4 ply; 1/2" ply drawers with Kansas black walnut fronts.

You'll notice that the benchtop got hacked up enough over the years that I used various bits of wood to patch it.

Can't go without this bit of history: Mid 70's. Central Eastern Kansas - northern edge of the Flint Hills. Elm Creek flooded its banks. Undercut a reasonably-sized black walnut, dropping it into the creek. In the only known instance of those two characters [I]EVER co-operating on ANYTHING, my Dad and his father-in-law got some chainsaws, some chain, and a couple Farmall tractors, and drug that sucker out, and took it to someone to saw.




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[Ned Otter]

Thanks very much for the photos, a real work of art and has lots of character. My bench when finished will look lean and mean, but will not have the personality of yours!

Ned


File under: Be careful what you ask for. I view the bench as a tool. It has drill holes, blade scars, everything. No apologies, but no bragging either. Not in same class as all the other benches seen here, but...has served me well.

The absolute very first solid-wood thing I ever made was my bench. Neighbor was doing rehab on a house built 1880's, down to the studs. It was framed in red oak. He tore out a section of roof. I scarfed up the wood. Maybe 40% yield gave enough for the bench top except for the outer rim boards, which were new. You can tell the difference in the first photo.

The dog hole spacers are Kansas walnut. Notice the dog on the bench - the holes are notched to receive the brass face. I don't remember where I got the dogs, but hadda be some well-known place, because I didn't know squat. Coulda been LL Johnson in Charlotte, MI. As mentioned, the hole spacers have an angle/cant to them - 7% sticks in my mind, but no guarantees. I stood in LL Johnson's showroom many Saturdays reading every reference book on building a bench, so that % musta come from one of those.

Cabinet is RO 3/4 ply; 1/2" ply drawers with Kansas black walnut fronts.

You'll notice that the benchtop got hacked up enough over the years that I used various bits of wood to patch it.

Can't go without this bit of history: Mid 70's. Central Eastern Kansas - northern edge of the Flint Hills. Elm Creek flooded its banks. Undercut a reasonably-sized black walnut, dropping it into the creek. In the only known instance of those two characters [I]EVER co-operating on ANYTHING, my Dad and his father-in-law got some chainsaws, some chain, and a couple Farmall tractors, and drug that sucker out, and took it to someone to saw.




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[Derek Cohen]

Having read a gazillion posts on workbenches, dogs, vices, etc, everything I've seen about creating square dog holes describes routing the holes in an apron strip, and gluing that "layer" along with others to the bench.

Why not simply cut and glue pieces of wood with the proper grain orientation to the apron at intervals of "square dog hole" width, and when dried, glue that entire assembly to the bench?

Thanks in advance --

Ned

Ned, no reason you cannot do this, as long as two conditions are met:

1. The partitions for the dogs are reliably secure - glue and screw?

2. I would also assume the the partitions are shaped for the dogs, since most square dogs are shaped for a recess as well as canted at 3 degrees (to self tighten).

It is easier, in my opinion, to do this as a strip and add it in.

Regards from Perth

Derek

[Kevin Jenness]

I agree with Derek. No reason why your plan won't work and be as strong as cutting the dog holes into a plank but it will take some care to keep the parts aligned and glue them securely. I would cut the fillers slightly thicker than the dogs including notches for the dog heads and secure them in place using spacers, glue, an 18ga. brad gun and clamps. I would run a plane or sanding block over the fillers before before gluing to the main benchtop. It's really no more work to dado a solid apron piece, plus you don't have to deal with keeping so many pieces aligned. A dado head in a radial arm saw or table saw (or overlapping cuts with a slide miter saw) will make short work of the main slots followed up with a router or chisel for the notches.

[Warren Lake]

seems to me and not looked for a long time but the Ulmias were done by dadoing one piece of wood full size of the slots then just the outer piece becomes the other side. ILl check.

Can see the dadoes are cut in the front piece of wood. this could have been done with a mortise chisel as well there is a step and ive not measured the metal dogs


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[Kent A Bathurst]

......... glue and screw?

This was mentioned a few times here. Got me thinking - always a risky proposition, I know, but still........

My walnut spacers are roughly 4-1/2" x 3-/4" in size, or just uner 17 square inches in surface area for glue adhesion. The goog found me a chart of Titebond shear strengths by product. TIII showed 4,200 psi. So I'm looking at 71,400 pounds of force to break that bond.

Let's say my skills at jointing limited me to achievement of only 50% effectiveness. In which case, I am led to this conclusion:

Until I swap out my 1.25" diameter acme thread tail vice screw for a 20 ton hydraulic jack, Ima thinking the screws wouldn't really have added much to the functionality.

[Derek Cohen]

Actually Kent, I agree with you ... I was going to edit my earlier post and remove the screws.

There will be about 3-6" between the dogs, I assume, which means that there is this amount of glued area times two (each side). That would be pretty strong.

Regards from Perth

Derek

[Jason Meinholz]

Not in same class as all the other benches seen here, but...has served me well.

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Wow, Beautiful bench Kent! I love the character.

Can you talk a little about the cabinet build, is it your design or from plans?

Thank you!

[Kent A Bathurst]

Wow, Beautiful bench Kent! I love the character.

Can you talk a little about the cabinet build, is it your design or from plans?

Thank you!

Too kind. Looks much worse in person. The El-um Crick [Kansas farmer pronunciation] Walnut classes it up. I made up the design kinda on-the-fly.

In the middle photo, you can see stretchers with wedged through-tenons. The ends of the bench are assembled frames, and the stretchers hold the bottoms of the frames in position.

The cabinet is nothing more than a 5-sided box [top,bottom,left side, right side, back] made of 3/4" RO plywood. Plus a divider inteh middle to support the drawers.

The bottom has two cleats made out of some kinda "layin' around the shop" wood, positioned to nest between the stretchers. The cabinet runs end-to-end between the legs, and overhangs the stretchers by an inch or two front and back. There is a 2" or so gap between top of cabinet and bench top BUT this works only because the dog holes are out in front of the cabinet. If they were over the cabinet, they would hit the top, and the cabinet height would have to be shorter.

The box slides into the opening, and the cleats align it betweeen the stretchers. It just sits there - no fasteners. Drawers made of 1/2" RO ply sides and 1/4" RO ply bottoms, 24"w x 20"d. Heights vary. Walnut fronts attached to drawer boxes. Handles made from RO.

Current load of stuff inside has to be well over 100#, so it ain't moving. There must be 35# of fasteners in just that one drawer.



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[Ned Otter]

Have spent a bit of time on a workbench with a classic tail vise, and from what I was told, you shouldn't really bear down too much, as it can cause the work piece to bow. Given that, and what was already said here, methinks glue alone will be good enough.

Milled up the apron today

Thx,

Ned


Actually Kent, I agree with you ... I was going to edit my earlier post and remove the screws.

There will be about 3-6" between the dogs, I assume, which means that there is this amount of glued area times two (each side). That would be pretty strong.

Regards from Perth

Derek

[Kent A Bathurst]

......... you shouldn't really bear down too much........

Milled up the apron today

I was just being a wise guy about the 20 ton press, of course.

Send photos when assembled.

[Jim Koepke]

Have spent a bit of time on a workbench with a classic tail vise, and from what I was told, you shouldn't really bear down too much, as it can cause the work piece to bow. Given that, and what was already said here, methinks glue alone will be good enough.

Milled up the apron today

Thx,

Ned

My bench came with a very simple (inexpensive) vise. Working with it over the years has convinced me simplicity can lead to versatility.

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This type of vice is subject to racking. To counter the racking a shim stack was built. The stack also has the ability to regulate how much pressure can be applied to the work being held.

Anti rack spacer stack > https://sawmillcreek.org/showthread.php?183743

jtk