Ideas for joining a workbench top to the legs (Schwartz inspired)

[kooshball]

My first real woodworking workbench build is well under way with the most of the design input coming from Schwartz' latest book. I have created a Mongrel of sorts as I have combined different design elements, vise types, and construction materials. Without a drawing the best description of my design is a SYP Holzhapffel type bench but with a large Jorgensen cast iron front vise and a quick-release vise mounted in the end.

The top is 3" x 27" x 6'6" and the legs will be 4" x 4" to give a height of 34".

I am building this as a workbench and not a piece of furniture so I am looking for function over form and as a result am considering mounting the top with 4 carriage bolts going through the top and the top stretcher. If I don't make any mortise and tenons will this be enough to keep the bench from racking? Also, if I do decide to go the m&t route, how should I account for seasonal movement of the top, just oversize the rear mortises as Schwartz suggests (but won't this compromise the stiffness and rack resistance of the bench)?

Thanks

 

[bluthart]

I attached a photo of my version of the 21st Century Workbench. I used side stringers joined by glueing mortise and tenons and drawbores. I drilled through and countersank lag bolts to attach it and haven't noticed any seasonal movement issues.

 

[kooshball]

You lagged the bench top to the top stringers or have I misunderstood?

Thanks?

 

[CrealBilly]

The top is 3" x 27" x 6'6" and the legs will be 4" x 4" to give a height of 34".

How about big ole hardened pole barn nails? Seriously drill a hole and sink them into the the top of the legs. Cut off the heads, drill a hole on the under side of the top and slip it overtop the nails. Somthing that big and heavy ain't likley to go nowhere and besides if you ever do want to move it, simply lift off the top and away you go.

 

[Gofor]

I went up through the center of the end stretchers with a 5/16" lag bolt on mine. Doesn't move and I can lift/drag the bench by the top without any problems. My top was about 2" thick, so I buried the lag bolt into it about 1". That way there is no metal on the top surface. Bolts in the center allow the top to expand and contract.

Go

 

[Bill Clemmons]

I went up through the center of the end stretchers with a 5/16" lag bolt on mine. Doesn't move and I can lift/drag the bench by the top without any problems. My top was about 2" thick, so I buried the lag bolt into it about 1". That way there is no metal on the top surface. Bolts in the center allow the top to expand and contract.

Go

I've used a similar approach to Mark. I used two lag bolts through the end (cross grain) stretchers, each a couple of inches in from the legs, and elongated the holes to allow for some movement.

Bill

 

[eyekode]

I don't think you have to worry about racking if the base is sound (the stretchers on the base are what really prevent racking, not the top unless it is a roubo style...). I have been researching the same subject and found it interesting that Frank Klausz attached the top of his workbench with two bullet shaped dowels from the stop stretchers mating into holes in the top. I.e. it is not fastened at all. It is heavy enough that friction and those two indexing dowels keep it from moving.
Salem

 

[ChrisB]

I don't think you have to worry about racking if the base is sound (the stretchers on the base are what really prevent racking, not the top unless it is a roubo style...). I have been researching the same subject and found it interesting that Frank Klausz attached the top of his workbench with two bullet shaped dowels from the stop stretchers mating into holes in the top. I.e. it is not fastened at all. It is heavy enough that friction and those two indexing dowels keep it from moving.
Salem

I built a bench very similar to Klausz's and used 1/2" dowels centered on the top stretchers that mate with holes in the top. After 25 years of hand planing, gluing, routing, and all the other abuse a workbench top takes I've never had it move or lift off the dowels. I also attached the long lower stretchers with long bolts and captured nuts so I could take it apart to move the bench in parts if necessary - which I've done 3 times since building it.

Chris

 

[bluthart]

You lagged the bench top to the top stringers or have I misunderstood?

Thanks?

I think that's what I did...

The two side stringers (I guess you call them stringers) are higher than the front and back "stringers" and come right up under the bench, which may be hard to see on the photo. The side stringers under the benchtop were very sturdy.

 

[bluthart]

I think that's what I did...

The two side stringers (I guess you call them stringers) are higher than the front and back "stringers" and come right up under the bench, which may be hard to see on the photo. The side stringers under the benchtop were very sturdy.

Here's a photo from underneath...

 

[kooshball]

Got it; thanks!

Looks like I may have over complicated things again. I am glad to see that so many folks have simply used dowels or lags and had good results.

Here's a photo from underneath...

 

[Mike Wilkins]

My own maple workbench is similar to yours in size, just a little wider. For attachment purposes, I just drilled a hole in the center of each top stretcher, using a 1/2" drill bit, wiggling it to enlarge the hole. In the benchtop underside I drilled a hole about 1 1/2" deep for a 1/2" lag bolt. I just used a ratchet wrench to screw in the bolt with a large washer on the underside of the stretcher.
Of course the bolts are centered on the stretchers and benchtop, so the top is free to move in either direction. Not a single problem in the 15+ years of use.