Ok, so. about using those steel electrical junction boxes.

[trotskyismyniece]

I originally bought plastic boxes from radio shack for my first two projects.  However, I hate how cheap and light they feel, and although i tried covering the entire insides with aluminum duct tape I don't feel like they're shielded.  Do those junction boxes provide shielding even though they're steel and not aluminum and has holes in them?  Are there any other downsides other than the difficulty of drilling holes in them?

[squidsquad]

They work well.
I use them often...easy to find & cheap.
Sometimes the holes that are already there may be slightly in the way of where you wanna drill for pots & jacks though.

[squidsquad]

Oh yeah...drilling near them semi-cut outs can also be tricky.
I punched out one accidentally once...had to use JB Weld to put it back.

[petemoore]

  I use credit card to spread JB weld...all across the outsides, and also put helper dabs on the inside to better re-inforce the punchouts I want to drill through, still have to use a backstop or clamp for drilling or take it easy when drilling...larger drill bits can grab and yank really hard.

[aron]

They work but they chew up drill bits and are really hard to drill compared to aluminum. A cheaper alternative (not as strong) is bent aluminum boxes.

[Chawk]

  I use credit card to spread JB weld...all across the outsides, and also put helper dabs on the inside to better re-inforce the punchouts I want to drill through, still have to use a backstop or clamp for drilling or take it easy when drilling...larger drill bits can grab and yank really hard.

Are you saying that JB weld can be used as shielding material?

[squidsquad]

Shielding needs to be conductive...JB Weld is not.  (I don't believe small holes are an issue for shielding)