Workbench top: Torsion box or hardwood laminate?

[Carlos]

My next shop project is to make a decent work/assembly bench. I can't decide on a top. I know it needs to be dead flat, and I think it probably should be really heavy, but not sure on that. I know a torsion box will be and will remain dead flat (assuming proper assembly). Will a glued-up top stay flat in the long run? I think so, especially considering our low humidity here. The heavy top would certainly be better for pounding on and things like that. I have a jointer, drum sander, and all the tools needed to glue up a large panel from something like hard maple. I have a local source for hard maple at a decent price.

My intended size is around 6' long by 3' wide, or maybe 2' wide, not sure on that. Seems like both wide and narrow have their advantages. Space is not an issue.

Your thoughts?

[pecker]

A torsion box makes a great assemlbly table, but one of it's benefits is light weight (comparatively).
Often, when building a wokbench, you want a lot of mass to insure the thing doesn't move around while planing, pounding. etc. So the maple top would be more useful, but more work to make.

I ended up making a sandwich of plywood and MDF. It's heavy and flat, and was cheap...which was a consideration for me.

[footprintsinconc]

i dont think that you need to make the top a torsion box. stability will come from how well everything is connected to one another. looking at the above posted picture, you can see that something as simple as what pecker has done is good enough. i think, you have to make sure that the legs are restrained enough at the bottom not to allow any type of movement (laterally braced in both directions). then the connection between the legs and the top and to the table top need to be a rigid one as well again laterally braced in both direction. the top then just needs to be thick enough to span between supports and finished properly to be stable and it will remain flat.

one of the ideas i liked on this site were by scott. after he has constrcucted the top, he has used wood laminate for floors as the top wear surface. he says that the results are a flat surface which is extremely durable and cleans real easy, including the glue that falls on it.

[mpauly]

Ditto what they said.

If you go with a laminate of MDF or Ply, definitely add some topper to be used as a work surface. MDF can swell pretty easily with any liquid and ply chips pretty easily. The laminate flooring is a good idea, but I went with some tempered hardboard which is cheap, easy to clean and easily replaced since I just have it double stick taped to the MDF top.

Michael

[jackellis]

From a structural standpoint, a torsion box is probably overkill unless you're assembling radial aircraft engines on it.

I'll probably go the laminate flooring route on top of MDF or ply since I have a box of the stuff. I need to find the right adhesive - carpenter's glue sure doesn't work well.

[LarryG]

You said space is not an issue, which is indeed what I recall from the SketchUp models of your shop. So my suggestion is: build both. A workbench with a thick, heavy, laminated top, set at normal working height; if you want holes for bench dogs and hold-downs, you can have them. Then build a separate, torsion box assembly table, like the one David Marks has on WoodWorks, with its top a foot or so lower than normal workbench height.

A down-low assembly table is just flat wonderful when doing glue-ups or other types of assembly for furniture-size projects. My TB assembly table measures 42" x 60" and has its top 21" AFF, the last being a minor compromise caused by my shop having only seven feet of headroom (Marks' assembly table top is, as best as I can judge, about 24" AFF). When I'm gluing up flat assemblies, I sit comfortably in a folding card table chair. When I'm doing larger assembles, I stand and everything generally falls readily to hand in the area between my knees and chin. No reaching waaay up over my head, as Norm is often seen doing on NYW.

Workbenches are the ticket for a lot of tasks, but IMO a lower surface makes all the difference when assembling anything but the smallest of projects. If I had to start giving up work surfaces in my shop, my TB assembly table would be the last to go.

[George Cole]

If you use MDF make sure you seal it...all of it and it will not swell or deform. I live in Georgia where humidity is a real bi**h. My MDF top has been on for 5 years ans still as flat as the day it was installed. Just my opinion according to experience.

[Carlos]

Heh, well, space is not an issue for one table, but two could be challenging. One thing I *really* want is a table I can walk around easily while assembling. And that is more of the need than a real "work" area; I simply don't hand plane anything, rarely hand sand, etc. I want a space for assembly, occasional use of the sander, pocket hole drilling, other hand drilling, etc.

The laminated top is a simple, cheap, interesting idea. And fast, I could have that done in a couple hours instead of days (which came first--the workbench or the workbench top which you need to build, and requires a workbench to build it on). It would be solid enough to bolt the pocket hole jig and a vise to.

[footprintsinconc]

mdf top will be fine. just seal both sides and you should be good. there are a lot of people who have done this and no one has said that its been a bad choice.

the only thing with the laminate floor idea is its durability and ease of cleanup of glue, etc.

[LarryG]

Heh, well, space is not an issue for one table, but two could be challenging. One thing I *really* want is a table I can walk around easily while assembling.

Oh, I see ... you meant space was no issue relative to a two- vs. three-foot wide top. Ah.

If you're going to be building full-size furniture, base cabinets, bookshelves, etc, I wouldn't go less than three feet wide, and preferably even more. My assembly table is the size it is because that was the absolute maximum I could squeeze -- and it was a squeeze -- into my previous, smaller shop. Now that I have more room, I'm looking at building one that's 4' x 7'. That'll be a bit of a squeeze, too, but I'm persuaded the larger working surface would be worth it.

Would you consider a low table with clamp-on risers for your pocket hole jig, vise, and so forth, to bring them up to normal workbench height? Would that work for you? BTW, on the issue of table size ... a lower table can be bigger than you'd think, yet not get in your way, because it feels smaller, as you're moving around it, when its top surface is down around your knees instead of up at waist level.

[Carlos]

Some interesting ideas. I suppose a work table with a flip-up extension may make sense, even if it's just a light hollow-core door? I have a decent amount of space but at the same time I'd like to maximize it. It's a three-car garage.

As far as the risers for some of the add-ons, I'm open to anything. Not sure what you mean, though I can picture the concept I've never seen it in use.

Some of the pointers above led me to finding these links, which have some good ideas:

http://www.canadianwoodworking.com/f...ad.php?t=20138

http://www.woodworking.org/InfoExcha...5e16923510b18a

[poolhound]

I have used both approaches. The torsion box does save on weight. I would also suggest a replaceable topper. I banded my main bench with 4" hardwood leaving it a 1/4 proud and then screwed down a sheet of 1/4 hardboard and gave it a few coats of wipe on poly. It has been very resilient but I dont worry too much about it getting dinged if it gets too bad I can just take it off and replace with a new piece.

Jon

[LarryG]

Risers could take many forms, but what I had in mind was the same basic concept as this Rockler dovetail jig stand that I stumbled across the other day.

For example, for your pocket hole jig, instead of attaching it to a slab of 3/4" plywood that you would in turn clamp to the bench/table, you'd add some legs or an open box under it, sized as required to lift the top surface up to normal working height. Then clamp the bottom of the legs or the box to the bench/table. If your assembly table was, say, 24" high, you'd make the legs or box about 8"-12" high (or whatever would yield the appropriate working height for you).

The space below could be used for accessory storage appropriate to whatever is mounted up top, in drawers or behind drawers -- although you'd obviously have to watch the weight.

Another option would be to have a raised section at one end or corner of the bench/table, semi-permanently installed, and then just swap out only the top "slab."

Yet another option is to provide some kind of lift mechanism to raise the whole work top up and down, over roughly a one foot range. I've seen various examples of this in books and magazines, using automotive floor jacks, scissors lifts, a base from an old barber's chair, etc. This would obviously be the most ambitious design but also the most flexible.

BTW, when you wrote "vise," I was thinking of a machinist's vise, as I know you also do metal work. I'm not sure this riser idea could be made to work very well for a woodworker's vise.

[rnelson0]

Heh, well, space is not an issue for one table, but two could be challenging. One thing I *really* want is a table I can walk around easily while assembling. And that is more of the need than a real "work" area; I simply don't hand plane anything, rarely hand sand, etc. I want a space for assembly, occasional use of the sander, pocket hole drilling, other hand drilling, etc.

Check out this ShopNotes mag - http://www.shopnotes.com/issues/097/

I am debating right now but am sorely tempted to build a scaled down version of the main bench. Underneath it is a cart for an assembly table. I like it because it has a lot of storage that you can get at from either side, it can be used anywhere in the garage or outside, and you can walk around it easily. You also get the workbench with the vice. Plus, they tuck underneath so you make good use of the area under the workbench and don't have to have two tables "out" all the time.

[Carlos]

BTW, when you wrote "vise," I was thinking of a machinist's vise, as I know you also do metal work. I'm not sure this riser idea could be made to work very well for a woodworker's vise.

No, I have one of those on the metalworking bench (which was actually much easier to build, as most metal stuff is). I was tempted to use it for woodworking too, since it's certainly solid and heavy, but it's always dirty and I've got the metal vise and bandsaw attached to it.

Thanks for all the thoughts and tips. Gives me a lot of useful things to consider. I think the idea of interchangeable "slabs" will be easy and work well. Something I can slide into the table as needed.