It appears that there are quite a few people interested in the sandbox I created about a year ago for my children since it appeared in the June issue of Domino Magazine. This is a little embarrassing for me because the photographer of the story for that issue made it look so interesting! In fact, the sandbox is made very simply from recycled materials - pieces that were left over from other projects mostly. Because we have received more than a few enquiries now related to its manufacture I thought I'd just post how I made it. In fact you can make this same sandbox within an hour or two if you have the right tools - and if not, I'm sure you can either borrow them from a neighbor or have materials pre-cut when/if you purchase the wood. It might help you to draw a simple sketch beforehand so that you give some thought to measurements. And remember, the measurements I give you are basic and you can change them to your own specifics:
Start with a 4 foot by 4 foot plywood piece for the base with a good thickness. I used leftover primer (1 coat) and exterior paint (2 coats) to coat both sides for weather proofing. No need to worry about color, since nobody will really see it. While the paint dries you can prepare the other wood pieces. After the paint dries you can drill some very small holes (anything larger will allow sand to fall through) into the plywood base all over the place randomly to help moisture escape if your sandbox is exposed to the elements like mine is. I set four corner studs using 4 by 4 inch pieces of cedar (perfect weather resistant wood) on top of the plywood base and screwed 4 screws in through the bottom of the plywood attaching the 4 corners. Each piece of corner stud I cut at about 5 inches in length. Halfway across from each corner stud I screwed an approximately 12 inch long piece of scrap 1 by 2 inch wood (that I cut from an existing 2 by 4 inch piece of wood) to the same plywood base. This would help secure the seam along the base when I put my sides on. To this basic frame I screwed in 4 lengths of wood (I had used left over cedar again) measuring 1 by 6 inches. The 6 inch sides would fit perfectly covering the corner studs and over the piece of plywood base. I would screw the sides in at the corners and along the approximately 12 inch long piece of scrap attached to the base to close the seam as tight as possible. It is worth remembering that 2 of the sides, from the 4, will need to be trimmed down 1 inch so that they compensate for the overlapping sides when assembled to the square framework. That means that 2 sides will measure 1 by 6 by 46 1/2 inches and the other 2 sides will measure 1 by 6 by 48 inches.
The most important thing for me was using scrap wood leftover from other projects. I happened to have cedar which is naturally resistant. You could conceivably use something like pine but you'd have to weatherproof it beforehand. If you do paint your wood, I would suggest eco-friendly paint so that you might consider using the wood later for a fire when the kids have outgrown the sandbox. For screws I used leftover drywall screws with good teeth on them. Weather resistant screws would be ideal for use if you have them. And, I don't suggest nails, especially if you live in cold weather climates, since the give and take will expose them sooner or later.
To finish off the project I screwed in some heavy rotating wheels under each corner and one in the middle of the underside for good measure and to handle the load. These you can find easily enough at your local hardware store. The larger the better since you want the sandbox off the ground by a decent amount. Then get yourself some bags of sand and pour them in. Though the sandbox is mobile with the wheels, it still will be heavy especially after you add the sand - so make sure you find the right location beforehand. I move our sandbox around the deck a bit so that I can sweep, etc.... but usually it takes a good push to get it started rolling!
Oh, and the best part about constructing you own sandbox is the satisfaction that you have personalized something your child or children will love to play with for a long time to come. And trust me, it is quite easy to do - by any means I am not the greatest of woodworking professionals. So, there you go.... I think I covered everything - let me know if you have any other questions.......