Since the most salient feature of a new toy is generally its novelty, you can make a perfectly adequate play stove by flipping over a cardboard box and drawing some burners on it. This stove is insanely overbuilt; I was mostly looking for an excuse to try out making "plywood" out of cardboard.
So, on to the cardboard laminate. A useful fact from the world of mechanics of solids is that the flexural rigidity of a plate increases with the cube of the thickness. In layman's terms this means that if you double the thickness, you make it eight times stronger. Corrugated cardboard already takes advantage of this fact by weaving a sheet of kraft paper back and forth between two flat sheets of kraft paper, making it much stiffer than it would be if the layers were all flat.
By gluing up many pieces of corrugated cardboard, we can make cardboard panels that are an inch or more thick and as large as we want. At 1" thickness, these panels are already quite strong; they can support several hundred pounds across a 24" span.
Not only are the panels made from recycled materials, they are themselves recyclable, so when all the fun has been exhausted, the stove can go out with the rest of the cardboard recycling.
Step 1: Save Your Cardboard Boxes
Once you have some "big" pieces, let the usual assortment of smaller shipping boxes accumulate until you have a good supply of raw materials, or your spouse starts yelling at you. Break down the boxes and remove any staples or overlapping segments---it's important that all of the pieces in a given layer be the same thickness. If you have boxes of varying thicknesses, sort your boxes by thickness.
The other things you'll need are:
* a gallon container of Elmer's glue
* a plastic drop cloth
* a utility knife
* some kind of saw. (I used a table saw, but a hand saw would work fine and would probably be less scary.)
* kraft paper packing tape
For the play stove, you also will need:
* 4' of bungee /shock cord
* some stove knobs, handles, black paper for the burners etc.
Step 2: Lay Boxes Out on Plastic
Look over your cardboard riches. Pull out the very best (large, flat, rectangular) sheets. Half of these will go on the top of the laminate and half on the bottom. If you can make the entire top and bottom layers from a single piece of cardboard, that's the best; if not, try to minimize the gaps. This is for both structural and aesthetic reasons. Most of the strength of the panel is in the outer layer, and anywhere you have gap it will be weaker. A refrigerator box cut into two big pieces, one for the top and one for the bottom, is ideal.
Anyway, set out the first half of your top-quality cardboard, with the "good" (unprinted) side face down.
Step 3: Glue Up Layers
Here my little helper (age 3 at the time) is spreading glue with a plastic spackling knife.
Step 4: Keep Adding Layers
Just remember to avoid filling the gaps between pieces with glue.
Step 5: Cover With More Plastic Wrap, Weight, and Let Dry
Cover with plastic wrap and put some weight on the whole stack. I think we used boxes of books and magazines that we'd never finished unpacking from our last move.
Step 6: The Big Panel
Using the table saw was a mistake; while you get nice straight cuts that way, the starting panel was so large that it was difficult to work with and therefore dangerous. Due to my excessive use of glue, there were also pockets of liquid glue in the interior of the panel to surprise the unwary and gum up the table saw blade. I haven't tried this, but I think a regular hand saw would work fine (it's only cardboard, after all) and would be a lot safer.
Step 7: Saw Up Into Panels
Step 8: Let's Build a Stove
Actual assembly was done with a hot glue gun and about 22 yards of 3" kraft paper packing tape from McMaster-Carr. This stuff is awesome; it's cheap, it's strong, it recycles better than plastic tapes. I recommend it for all of your packing tape needs.
Step 9: Customer Focus Group
Step 10: Set the Oven Floor
I didn't do the hinge quite right. Since my panels were an inch thick, I should have set the hinge so that there was at least a full inch of space between the inside surface of the hinge cardboard and the rest of the stove. I made the gap too small and had to remove a bunch of material from the door panel.
In order to make the front of the door look smooth I glued another piece of "good" cardboard to the front so everything was flush. With good planning you could use a single piece of cardboard for the whole front of the door, which would look best.
Step 11: Tape, Tape, Tape, TAPE
Step 12: Structural Complete
You really can treat the laminated cardboard like a building material and saw it, drill it etc.
Step 14: Structurally Complete!
We ended up wrapping the entire stove in kraft paper tape because it looked better that way. While I kind of dig the utilitarian look, I think play value for my kids probably would have been enhanced if I'd gotten some bright-colored contact paper from the variety store and covered it in that instead.
You can hide a lot of goofs this way.
Step 15: Door Springs
My first try was velcro, which worked poorly; the velcro-velcro bond was stronger than the velcro-kraft paper bond, so they'd just rip right off. Plus the kids never put the door back up when they were done playing, because they're kids.
Finally I came up with the bungee cord strategy below. This works great; the restoring force increases as the oven is pulled down, but is near-zero when door closes. The cords are held by drilling two closely-spaced holes, threading the shock cord through and tying it on the inside. Simple, safe and reliable.
Step 16: Bling It Up
Little helper is now not-so-little, being 6 years old and 4' 3". Her younger sister is 2. While the play kitchen has never been their favorite toy, the kids do still like it. (At least the pink commercial one isn't any more popular than the home-made one.) Popularity rises when friends come over, as cooking is a good group activity even when it is pretend.
Probably the best feature from my point of view is the large capacity of the oven. It can hold a lot of toys; this means the overlords can sweep in, pick up all the play food etc, and toss it all in the oven.
Step 17: Technical Drawing
The construction is basically:
* Cut out pieces. I started with 7 16" x 24" panels, but some of them weren't that great and being able to cut away parts of them was a bonus. The scrap just goes out with next week's cardboard recycling.
- 2 16"x24"x1" panels ("A"),
- 2 16"x21"x1" panels ("B")
- 3 11"x24"x1" panels ("C")
- 1 18" x 22" x 1/8" (plus tabs and hinge) oven floor panel.
* glue and tape 2 C's (bottom back, bottom front) and 2 B's (sides) to make a 4-walled structure.
* set the oven floor across that box. Do a better job with the hinge than I did.
* glue and tape 2 As (top back, stovetop).
* attach the final C to the hinge.
* bungee cord it.
* add the bells and whistles.
As mentioned I haven't tried standing on the play stove, but I've sat on it. It can certainly hold a couple of hundred pounds. I will be interested to see what other things people can make with laminated cardboard!