2x4's and plywood or cardboard grow box?

I'm planning on building my first grow box pretty soon, but I can't decide what I should make it out of. I saw this YouTube video (watch below) of someone who made a grow box by attaching two cardboard boxes together using bolts and washers. I thought of making one just like that, but after doing some research it doesn't look like the safest idea, and lots of people were saying that making one this way is a big fire hazard. The other idea I had was making one out of 2x4's and plywood, but I'm not sure how to make one this way, could anyone tell me the best way to make a box this way?http://youtu.be/gyo17C6rOR0

Use PVC for framing and panda film for the walls. Pretty simple.

Man, if you don't already have the wood working knowledge to build yourself a competent box, to be honest, not trying to be a dick, you will be better off buying a tent.
They're made for it, with holes and everything already there for you, and probably cheaper than buying 2x4's, sheets or half sheets of wood, silicone to seal it, Mylar or paint, screws, etc.

I agree a tent will be cheaper and safer then building your own unless you have the know how then by all means build away, because I know the feeling of wanting a custom room the way you want it.

building your own box is not difficult. Make sure to measure twice and cut once tho. Like everyone else said the cost to build your own unless your have all the tools and things needed is almost the same as buying a tent.

i got my 2x4 in tent today, cost $80. i already know the investment is worth it this is built very nice

Your mama raised a smart boy. Let us know how you do.