The Dundle Anti-Sand Filter

First you need the bits. I had an old bit of wire grid laying at the back of my shed.

Any old sponge will do.

Cutters for the wire, scissors for the sponge and one adult for supervision.

Next pull the air pipes apart and cut the grid to make a round cartridge shape. Note the sides go up the pipe and double back around the joint

Cut the Sponge to fit the pipe being careful not to lose a pinky.

When you get to the sandy places, dip the sponge in oil, place in the cartridge and join the pipes.

Don’t forget which way the air is sucked through the pipe!