Raising Workbench Height

[Jonmustang]

I recently scored both a heavy, 6' long, steel table and a 9' solid-oak workbench with a 1-1/2" thick plywood top... both for free. However, both are 30" high, and I think something more like 36 inches would be a lot more comfortable to work on.

I'd like the steel workbench to become my welding table, and I suppose I will just fabricate some steel feet around 6" tall and weld them on. Raising the height of the oak workbench is a bit more of a question. I'd want it to be very strong, and just attaching a few more inches of oak to the bottom with some basic joinery technique might be fine, but perhaps there are some alternate bright ideas out there?

I have considered 6" casters, but wouldn't want it to roll around at all when I'm working on something heavy. Perhaps rigid casters instead of swivel? Are there extremely heavy-duty, solid steel, height-adjustable feet that can be bolted on to the bottom of 4 x 4's?

 

[The Cobbler]

if you are a welder, which by admission you seem to be, weld up 4 collars that slip over the 4x4 legs and fasten them . add whatever height or adjuster you want to the bottom of them.

 

[kbs2244]

I used 4x6 timbers from leg to leg to raise a table enough to get my knees under it.
Simple and cheap.
And easy to un-do if I ever need to.

 

[Cyberbear]

Go to your used metal yard and look for some heavy wall square tubing that will slide over the existing bench legs. Fabricate some simple extensions, fasten them accordingly, and you're good to go...