work bench/table and holdfasts

[Absinthe]

Hi,

I am just setting up my shop now that I have the room to do it. First thing I did was make 2 work benches/tables to give some flat surface area and additional storage. They are both the same 2'x4', 2x4 construction with a "top" and a bottom shelf.

I just finished cross bracing and attaching the .5" birch plywood shelf.

For the top I had planned 2 pieces of 3/4" birch plywood laminated together with perhaps a sheet of Masonite attached with DST for easy removal/replacement.

These things are rock solid, the "L" design on the legs gives them enough surface area that I will with I put casters on it. I was able to get on top of it and rock back and forth without sliding or racking. I think I could actually plane on this. Not bad for 7 8' 2x4's each with very little waste.

Anyway, I am considering perhaps adding some holdfasts but I wonder, will 1-1/2" of birch plywood be enough to support them, or will they just make oval holes? Do I need to perhaps add some additional wood underneath the holes or should this be sufficient?

 

[Mark Gottesman]

Here is a previous thread that will help you decide. http://www.ncwoodworker.net/forums/showthread.php?t=39439

 

[KenOfCary]

Good question - I think 1-1/2 is going to be insufficient for standard hold fasts such as the Gramercy one's. However Lee Valley sells some specialty bench dogs and hold fasts that would probably work just fine. They are not cheap, but are very versatile and would definitely work in the less thick top you describe.

 

[Absinthe]

I promise I searched first, and didn't find that thread. Of course when I do the same search now it comes up. Sorry.

 

[smallboat]

just a thought, but you would only need the additional thickness in the area of the dog holes.
would a strip or two added underneath solve the problem w/o doubling the thickness of the whole bench top?

I'm in a similar place having built a truss box style work surface (wouldn't call it a bench)
Pondering next steps

 

[Rwe2156]

If you really want a ww'ing bench, then as we say in these parts "you're going away from home" building it as you describe (IMHO).
If its just a "bench" bench its ok, but if you want a bonifide ww'ing bench you need a solid wood top and a solid, massive undercarriage to support it.

But if you're sold on doing it this way I would suggest adding a couple sheets of 3/4 MDF to add some stiffness and density.
A sandwich of ply|MDF|MDF|ply laminated together with contact cement would be my suggestion.
But before you do it make sure you've got a planar surface to do the glue up or you'll have a warped top.
When I build a torsion box top for my assembly table, I set up my saw horses with a level, some jointed 2x4's and winding sticks to make sure my plywood was dead flat before assembling it.

Anyway, if you do a thicker top you'll have plenty of thickness for bench hooks.

 

[Absinthe]

DrBob, I am not sure how to follow the thread relative to replies since they all seem to come at the bottom. However, if this was meant for me, I would agree that my benches are not true woodworking benches by Roubo or even Scott Landis' standards. 2'x4' is well undersized or such things, and it doesn't have nearly the requisite $1000 worth of laminate hardwood in the top. I was going for utility tables that would provide a nice work/layout area and some under table storage. I went with some of the advise that Swartz gives in the Nike vein of "Just Do It" and get to working. All benches, and for that case (all flat surfaces) become work benches in my shop. Usually all it takes is a clamp. I could put some holes and fasten hold down clamps to the top, or even make big enough holes and put a clamp through it. But I thought, if the top would handle it, then a hold fast might be convenient.

 

[pviser]

Rwe2156 (DrBob) is definitely on target about achieving a planar surface. This is difficult to manage with plywood, but it can be done. There are various techniques used, but my two cents worth is this: a planar surface is worth its weight in gold, and the time you spend on this will repay you countless times in the years ahead.

 

[Gofor]

My bench has a 2" thick white oak top, and hold fasts work just fine. I think if you glue 1 more layer of 3/4 under the top in the area of the hold fast holes, it will be plenty.

JMTCW

Go

 

[merrill77]

A woodworking bench is any bench that effectively assists your ww'ing. There are no hard/fast rules on the specifics.

For a mostly power tool woodworker, you'll want a variety of ways to hold the wood. For more hand tool oriented work, the bench needs to also resist the (mostly) lateral forces produced during sawing, planing, etc. That can be accomplished in a couple of ways. A lightweight bench can be attached to or oriented against a wall to add that stability. A free-standing bench needs to resist the forces on its own: (1) it must remain in place either by being attached to the floor or by sheer weight & friction and (2) it must be stiff enough to not bend/rack in use.

With good design, this can all be accomplished without a massively thick top and legs.

In my experience, the holdfasts will benefit from more thickness in the top...but only the area arount the holes needs it. They work great in my 2.5" oak top. IIRC, Gramercy recomends at least 2".

 

[KenOfCary]

The benches that we have on the Outreach trailer are essentially torsion boxes with metal leg assemblies. They have to break down and be assembled over and over so that is part of the reasoning there. The torsion boxes have framing members inside wide enough to drill 3/4" dog holes all the way through. This is an option.

 

[Gofor]

My bench has a 2" thick white oak top, and hold fasts work just fine. I think if you glue 1 more layer of 3/4 under the top in the area of the hold fast holes, it will be plenty.

JMTCW

Go

To clarify, I was suggesting adding one more 3/4" layer under the double layer top for a total of 2 1/4".

Go

 

[Rwe2156]

DrBob, I am not sure how to follow the thread relative to replies since they all seem to come at the bottom. However, if this was meant for me, I would agree that my benches are not true woodworking benches by Roubo or even Scott Landis' standards. 2'x4' is well undersized or such things, and it doesn't have nearly the requisite $1000 worth of laminate hardwood in the top. I was going for utility tables that would provide a nice work/layout area and some under table storage. I went with some of the advise that Swartz gives in the Nike vein of "Just Do It" and get to working. All benches, and for that case (all flat surfaces) become work benches in my shop. Usually all it takes is a clamp. I could put some holes and fasten hold down clamps to the top, or even make big enough holes and put a clamp through it. But I thought, if the top would handle it, then a hold fast might be convenient.

Yes it was meant for you and as I said, if this is more of a work bench, then the multiple layers or, even better, a torsion box top is still a good investment going forward.

The main reason I said multiple layers was to give you at least 2" of top, the minimum thickness to use holdfasts effectively.

Good luck, just take care of your lungs if you do go with MDF.

 

[Absinthe]

Thanks DrBob, I should be close to 2" with 2 layers of ply and 1 masonite, but I am not opposed to adding some 2x4 pieces under the holes.
I have watched the videos on torsion boxes and they really seem like a lot of work. Perhaps for a different table.
Hopefully I will not be doing any MDF work until after I get the ClearVue1800 going. I have to figure out where everything is going, or come up with a flexible way of laying out the ducting first. (and attach the whip.) But it is mounted One step at a time.

 

[Rwe2156]

My bench has a 2" thick white oak top, and hold fasts work just fine. I think if you glue 1 more layer of 3/4 under the top in the area of the hold fast holes, it will be plenty.

JMTCW

Go

Can't compare a hardwood to plywood its a far better, stronger top.

Hes using plywood. If he uses holdfasts, the holes will get wobbled out pretty fast.
Best way to get around that is make it thicker.
....IMO, of course

 

[Rwe2156]

Thanks DrBob, I should be close to 2" with 2 layers of ply and 1 masonite, but I am not opposed to adding some 2x4 pieces under the holes.
I have watched the videos on torsion boxes and they really seem like a lot of work. Perhaps for a different table.
Hopefully I will not be doing any MDF work until after I get the ClearVue1800 going. I have to figure out where everything is going, or come up with a flexible way of laying out the ducting first. (and attach the whip.) But it is mounted One step at a time.

Actually a torsion box is pretty easy to build and I think its well worth the investment.

 

[Gotcha6]

Can't compare a hardwood to plywood its a far better, stronger top.

Hes using plywood. If he uses holdfasts, the holes will get wobbled out pretty fast.
Best way to get around that is make it thicker.
....IMO, of course

This may be going around your elbow to get to your thumb, but why not over bore the hold fast holes and use a shouldered insert glued & screwed in from the bottom? Make it about 2-1/2" in diameter (Or square) with a shoulder on it to glue from beneath? It could even be a stacked & glued assembly.

 

[Absinthe]

Actually a torsion box is pretty easy to build and I think its well worth the investment.

Just seemed like a lot of exacting and leveling and such.

 

[Mark Gottesman]

I have been looking at building a workbench in the near future. I plan to make the "New Fangled Workbench" from FWW. The first runner up was a "Torsion box Workbench" http://www.popularwoodworking.com/projects/toms-torsion-box-workbench . My feeling after reading the article and a few web threads is that the build was well within the scope of a maker with a basic shop and would yield a flat and stable surface with minimal effort.

JMTCW