Building a sandbox

I wanted to build a sandbox for the kids to play with on the patio. Kurt quite liked playing with a "sandbox" that just consisted of a plastic tub at Rachel's parents, so I figured anything bigger than that would be ok. I settled on 60x90 cm, because all four sides for that could be cut from a single 10' (3m) piece of 2x6.

I cut the pieces to length on the table saw, as always. I don't have a miter saw. You pretty much need to dedicate a whole wall to such a saw to use it effectively, and I would rather not.

The corners are joined with very coarse sort of "box joints", which I cut using a small table saw sled and a sturdy wooden shop square that is meant for jigging things up with and clamping to.

For the joints shown here, I cut the slot wider on one side so I could easily get in there with the bandsaw to cut out the bottom.

for the other parts I was able to cut the shoulders won the tables saw.

The ends of the joints will protrude a bit (that's easier than getting it exactly flush), and I bevelled all the ends on the belt sander...

... except for the inside corners, which I sanded on the strip sander.

I could have used a knife for these too, but with the strip sander next to the belt sander, it was easiest to just move over to that one.

Test fitting the box together. My initial thought had been to just make the sides of the box out of one 2x6, so it would be 5.5" or 14 cm deep, but then I decided to add another 2x4 below that to bring the depth up to 9" or 23 cm.

I wanted to use screws to join the side pieces next to each other. Glue is usually a bad idea for things that get wet periodically. But the longest deck screws I find were 3.5" long.

So I drilled holes in the 2x4 pieces so I could sink the head way into them without risking cracking the 2x4.

Plus a pilot hole all the way trough. If the thread on these deck screws engages both pieces, then the thread prevents the head from being able to pull the pieces together effectively.

I also cut out a 4 cm deep notch on one of the long sides to make it easier to reach into the sand box.

And pilot holes in the box joint shaped ends. With the screws so close to the ends, I didn't want to risk splitting the wood.

Then screwing the 2x6 frame together. The box joint ends make for two screws from above and one screw from the end.

I then screwed the 2x4 frame together and screwed it to the bottom of the 2x6 frame (the box frame is upside down in this picture).

Then screwing 1" thick cedar boards onto the bottom. These are inset from the edges to to hide them a little. I also bevelled the ends.

These two pieces will form legs to raise the box up a bit.

These legs are screwed on from the inside, so I flipped the box over again, carefully positioned the legs under it and measured where they should be and screwed down into them.

I wasn't originally planning to make a lid for this box, but everybody warned me about stray cats pooping into sandboxes. I haven't seen any cats wandering in our yard so far, but I figured I'd make a lid just to be safe.

I started by making a frame out of 1" thick cedar.

I got a scrap of roofing sheet metal just large enough from a friend.

I cut it to size by making a deep score with a utility knife where it needed to be cut.

Then bending it across the score line. At first, it's hard to see how this will break it because it only bends slightly more on the score line than everywhere else, but enough so that it yields more on the score line, and by the second back and forth, the score line forms a sharp corner. a few more bends and it breaks on the line.

I then bent it down over the edges of the frame. I was able to bend down the ribs quite nicely by making a short cut down the middle and then folding down either half.

But folding the ends down over the frame got real inelegant and the result didn't come out as nice as I had imagined. A proper metal brake would be nice, though with the corrugated metal, even a brake might make a mess of it.

But I decided that it was "good enough". There are still some exposed edges, but I sanded them all so they don't cut, and realistically, this thing doesn't have any sharper edges than other things the kids already play with.

Rachel dumped five 20 lb bags of "play sand" into it. I think four bags for a box that size would have been enough, but we already bought the five. In time I'm sure the level will go down!

I put a piece of polyethylene foil in the bottom before we dumped the sand in. This will keep the sand from going through gaps between the boards and will also help to keep the floor of the box dry.

The kids were very enthusiastic about playing with this sand box. And the way it's sized and off the ground, its easiest to play with while standing next to it as opposed to sitting in it. I'm hoping that this will make for less sand getting into the house.

The whole box is designed so there aren't a lot of places where moisture gets trapped in the wood, so hopefully, it will last a long time without anything rotting out.