How to make blast gates for your woodworking dust collection system
If you are a DIY enthusiast, you will know how much of a problem sawdust can be; however, you can install pipes to channel the dust from different equipment and blast gates to help you collect and control the flow. Here we look at a simple way to make blast gates.
Each blast gate starts with two equally-sized square pieces of plywood six and 11/16 of an inch square. Once you have 16 plywood squares, you need to carefully measure and draw the circle. Four-inch diameter PVC pipe has an exterior diameter of four and 3/16 of an inch. The pipe needs to fit snugly into the hole.
Use a jigsaw or palm router to cut the holes precisely in the centre – they need to line up!
For the next step, you will need PVC pipe coupling; one coupling can be cut in half to provide the necessary pieces. Once you have cut these, you need to sand them gently. This will help to make a ductwork blast gate damper in the style of those sold by retailers such as http://www.dustspares.co.uk/Blast-Gate-Damper.html.
Cut lengths of PVC piping into one and one-quarter inch lengths. These can be fitted into the holes in the plywood squares and fixed with PVC glue. One end of the pipe length should be flush to the plywood, with the other extending outwards. The PVC coupling can be fixed over the protruding pipe.
Now fix the halves together. You need to make spacers to keep the two halves of each gate one-quarter of an inch apart, as the sliding section will be made from one-quarter of an inch-thick plywood. You can fix the spacers and the gate halves with construction adhesive.
Finally, make the sliding gate. The sections of plywood you use here should be 12 inches long. This time, the hole needs to be off centre. You can use the existing gate halves as a template to fit the hole to one side of the sliding section. You can also fit one-quarter inch sections of pipe into the hole once it has been cut.
For ease of use, fit handles to either short side of the sliding section, ensuring that one is removable for maintenance purposes. Fit the sliding section between the two gate halves.