attaching quick release vise question

[Steven Lee, NC]

My current workbench is an mdf torsion box about 3.5 inches thick. I want to add a quick release vise but am feeling that attaching it straight to mdf is not a great idea? I forget if its 1/2" or 3/4" mdf. Think gluing 1" board to the torsion box bottom and then attaching the vise to that will work or should I go thicker?

I want to do a flush mount version

Vise-installation-1.jpg

[Mac McQuinn]

I also used a torsion box for bench top although went with 3/4" MDO. I anticipated installing a Record 52-1/2 so glued in place two 2x6" blocks inside the corner of Torsion box. This gave me approximately 3-3/4" of material thickness to bolt to. I then attached the vice which is pretty heavy with lag bolts. Very secure.
Mac

[glenn bradley]

A solid area inside the torsion box in the anticipated vise location would be best. Solid areas leading out from the vise location for dog holes are also advised. At 3-1/3" thick already, adding more material to the bottom places your torque point (vise screw[s]) rather low. I went with a vise as opposed to vise hardware for just this reason on my 3" thick top. Realizing your torsion box is already constructed, I would still not hesitate to cut in from the bottom and install some solid material to mount to. JMHO.

[Steven Lee, NC]

unfortunately I thought I had a great idea and put in a bunch of t track thinking I could clamp things down with it but it's not working out so well. So I have no wood inside the cells to drive into.

[Steven Lee, NC]

hrmm,never thought of going in through the bottom, I'll check it out when I get home tonight

[Erik Christensen]

Steven - I agree with Glenn - I would cut out of the bottom skin a square access hole to let me add a solid block of wood that would fill the hole & be flush with the bottom skin when installed. Flip the bench upside down, cut the hole, fit the 'wood plug' and epoxy the crap out it. if you want even more support for the block interior to the top - after the epoxy is dry drill a few holes around the plug and fill the void with expanding foam - once that sets you should have a good attachment point for your vise.

[Mike Zilis]

I was going to suggest mortising out space on both the top and the bottom for a flush fitting hardwood insert. This way you can get the screws to anchor at both ends while passing through a layer of MDF in the middle.

[Jim Matthews]

+1 on MZ's method.

There's some necessary excavation, ahead.