Workbench joint designs

[realeyz]

I have referenced all the books I can find and they all showcase the typical joints for woodworking like lap, biscuit, mortice and tenon, rabbet, dado, etc etc, but none of them seem to handle joints with multiple pieces that cross each other like I am dealing with in this design for my built-in workbench. I have identified the 7 different joints in the illustration and started designing different types of joints that are possible for the upper post cross joint. I would like to get feedback on which would be the best from a strength standpoint. Of course any other things I may need to consider are also welcome and encouraged. More joint designs for the other 6 joints will be posted later. The 2x4's will be anchored to the walls. Keep in mind also that the flat bench top will be laid on top of this of course.

seems like the best choice is the screwed lap joint. The quad corner tenon lap joint I realize is a bit silly and not really practical for this.

thanx for any and all advice!!

- todd

[Chris Friesen]

If you fasten it to the walls, racking won't be an issue and you could probably get away with just about anything.

Also, 4x4 is vast overkill for your posts. A 2' vertical section of standard 2x4 can hold 4500lb in compression.

Chris

[Bob S]

Todd,

You asked for advice and ideas before about this and none of those that you indicated would be incorporated are reflected in the drawing you're showing. Unless you'll be throwing engine blocks up on the bench, do away with the

4x4's and use 2x4's. Change the drawing then come back. Simple lap joints (glued, doweled or screwed) will suffice for most joints here. If this was a free-standing workbench subject to racking forces and heavy loads then I would use 4x4 legs (actully laminated 2x4's to make 3x3-1/2"). You have over-engineered this and making it way to expensive for what you need.

Bob S.

[Jim]

I'll agree with Bob. I recently made a movable table for my old table saw, and I used nothing but 2x4s and lap joints. I can sit on the table anywhere without seeing deflections. I did use screws "till the glue dries". The table saw weighs about 250 pounds. Jim

[Andy Dingley]

So change the design. You don't need those joints, they're a pain to make and they're less strong than staggered joints. Everything you need for a workbench you can do with M&Ts, either wedging them, pegging them, or (if you want to be posh) half-dovetailing them and using a wedge to lock the other half of the dovetail.

you really must do 3 or 5 way joints, look at Japanese techniques, as described in Nakahara's "Complete Japanese Joinery"

[Teamcasa]

I see others have boo-hooed the 4x4 but I like them for legs. They add mass and reduce bounce when I hammer something stubborn. As for the joints, a simple half lap that I epoxyed then screwed have help up for twenty years without any problems or loosening.

Dave

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[Dave Jackson]

If your interested in the quick and dirty, go to the hardware store and look at the selection of Simpson products. They are a common brand name for joist hangars, but they also manufacture many other metal connectors to join things together. --dave

[realeyz]

Here are some of the lower corner joint designs:

think the inner miter dado joint looks the easiest and strongest. I also like the way it looks put together with two different toned woods. What do you guys think?

-todd

[Chris Friesen]

Any of them will do the job, given that you don't need to worry about racking stresses.

In this application glued and screwed butt joints would probably be sufficient.

Chris

[DonkeyHody]

Todd, You indicate elsewhere that you have very little woodworking experience. You'll find these joints much more difficult to make with actual wood than they are with computer programs. You will quickly ruin some of your wood and be going back for more if you attempt such complicated joints without more experience under your belt. All of us make mistakes, beginners make more of them. I don't care how smart you are, there are skills involved here you simply haven't learned yet. I assure you that wood glue is plenty strong to hold your bench together with only the simplest joints and a few screws.

DonkeyHody "Good judgement comes from experience. Experience comes from poor judgement."

[Mortimer Schnerd, RN]

Wouldn't it be better for him to learn this constructing something for the shop than something for the living room? Let him try. This is exactly where he should become adventuresome.

Pine is a hell of a lot cheaper than cherry.

[DonkeyHody]

Your point is well taken. I'd just like to see him make some simple half-lap joints before he starts trying to get fancy. I see great potential for him to become frustrated and quit if he bites off more than he can chew.

Reminds me of the time we took the neighbor's 13 year old kid skiing. He had a snowboarding video game and was very good at it. He thought he would be doing jumps and flips right away. That's about all you see people doing on TV, right? By the end of the first day, he was totally demoralized and wouldn't try it again.

DonkeyHody "Good judgement comes from experience. Experience comes from poor judgement."

[Swingman]

Sometimes it is more tragic than that.

I was raised on a horse farm and, at one time in my "yoot", spent a good part of my time astride, from steer roping in rodeos, to riding hunter/jumpers on the SW show circuit, and even got into training for a period after getting out of the service.

One of my mentors was an old man who had owned a thriving stables since the turn of the century, when horses were still a major means of transportation in this part of the world. It is safe to say that Mr. Vaughn Parrish died knowing more about horses than most self-styled horseman today will every know, and was a damn good example of what constitutes a "horseman", by any definition.

So I had to initially laugh last year when a friend told me about this "expert" horse trainer she was letting "train" her show horses ... a 14 year old girl. This girl "had all the horse movies and training videos" and "really knew horses" ... until she put herself, and a horse, in a position that no remotely knowledgeable horseman would have considered.

As a result the young lady is now a quadriplegic, from an unnecessary accident caused by poor judgment and ignorance.

... and the fact that this friend is an MD just further illustrates the state of a culture that hasn't even considered that little bit of wisdom.

[realeyz]

Thanx guys - here is the assembly with the mortise and tenon construction:

know I have no experience with with this kind of wood joinery - I plan to practice on old wood before really using any bought material for the bench. I may use big 1 1/2 dowels for the tenon instead of trying to cut square mortises - those look tough. This way I can just cut the holes with a big forstner bit. In any event I will practice the methods before diving in. If it turns out to be too tough I will just revert back to using doubled up 2x4's

Thanx for all the ideas and encouragement - it is much appreciated!!

- todd

[Andy Dingley]

design is beautifully rendered and very poor mechanically. Look at any other similar piece of framing and study the joinery used and the proportions of the tenons. As a quick clue, mortices shoudl be longer than their width - square is bad, and tenons should have two shoulders, not four.

I suggest reading "The Workbench Book" for starters, and probably something (Tage Frid?) on how to design good proportions for joints.

[realeyz]

OK I have had a lot of feedback about the mortise and tenon being wrong in many different ways so I have adjusted and made some treatments for the different joints. If you would be so kind as to let me know what you think it would be most appreciated.

again - all your comments are mucho appreciated!

- todd

[Andrew Barss]

realeyz wrote: : OK I have had a lot of feedback about the mortise and tenon being : wrong in many different ways so I have adjusted and made some : treatments for the different joints. If you would be so kind as to : let me know what you think it would be most appreciated.

:

seem to have all logical options covered. Why not rely on hundreds of years of past experience? Get Landis' the Workbench Book, and see what's worked in the past (hint: it's not very complicated).

-- Andy Barss

[Ricky Robbins]

Reminds me of an early driving lesson I was giving my daughter. Around the block, and we're approaching the driveway. I wait for her to slow down, we're getting closer to the driveway. I don't want to be overbearing, so wait an instant or two more. We're doing about

20-25 as we approach the driveway. "You have to slow down" I say, and she does - to about 15 for a 90 degree turn. Next thing I'm grabbing the wheel to keep us from climbing the bank beside the driveway, and telling her to hit the brakes. After we stop, I told her you can't turn that fast. Her response: "You can in _Need for Speed_" (video game). Yeah, darlin' but that's a Ferrari, this is an Aerostar.

(She's gotten better over the past five years.)

Ricky

[AAvK]

Todd, if you have a drill press and forstner bits, as well as a 1" chisel and mallet, you can cut mortises.

The forstner bit should be the same size as the mortise will be wide, cut a row with each plunge close together, like 1/3 the size of the bit, wood up against a fence and clamped down on the table. Then it's chisel time, you can figure out the rest of that.

If you have a back saw, 12" to 14" or 16", you can cut tenons too. If it's a more basic quality of saw like a Sears, just cut on the inside of your marking lines, then chisel down to size, cleanly... even with a goddamn Sears chisel!

(just to see one, if you don't know)

Hand experience, as much as possible, is a great way to learn woodworking, this is what I am doing, and using stationary tools like table saws I keep to a minimum.

...hope this helps,

[Leuf]

But save yourself a lot of cursing and sharpening by making sure any knots in the 4x4s are not where the mortises go. I learned that one the hard way..

-Leuf