Rangehood, the adventure begins!

The first step in building this range hood is build the forms which will shape the curve. To do this, I need a template.

I used 3/4" MDF to make the master template. I started by drawing out the profile of the curve, extending it a couple inches on either end. This involved revisiting high school geometry, which I won't go into.

Once the shape is drawn out, I cut out the negative portion of the curve on the bandsaw, and cleaned it up with the belt sander. The faces of the hood are concave, which can be difficult to vacuum press, so to make my life easier, I make the forms convex. The face of the form describes the outside face of the vent chase.

To help register the template on the foam, I drive two screws through, which will stick into the foam to hold the template in place while I cut the foam on the bandsaw. Notice how this form will have a flat portion near the top of the hood.



The body of the form is made from rigid foam insulation, its light, cheap and strong enough to hold up in the vacuum press. Using the template and bandsaw, I next cut out foam duplicates. I used spray adhesive I glued the foam parts together to make the form body.



Finally, I covered the form face with 1/8" bending plywood. The plywood provides a smooth face and smooths out minor imperfections in the foam.

Here are the completed form, ready to use. It is wider and longer than the working pieces from the panel, this allows working room.