Vacu-Form Table

The purpose of a vacu-form table is to heat a sheet of plastic to its glass transition temperature then force it to conform to a given shape by means of vacuum pressure.

The frame for the vacuum box.

Vacuum box with bottom attached.

Had to do a lil math for the parabolic reflector contour.

Ribs for the parabolic reflectors.

Ribs inserted into the heating element box.

Bending the aluminum sheet for the reflectors. Aluminum has far better reflectivity than steel at infrared wavelengths. Infrared heating elements are the heat source to bring the plastic to its glass transition temperature.

More bending...


Still bending.....

Test fitting the first reflector. The purpose of these is to uniformly distribute the thermal radiation onto the plastic.

Another view of the heater box.

Better view of bending the sheet metal. Who needs a sheet metal bender when ya gots plywood and muscles!

Reflectors fully installed.

Using extra aluminum for heating element brackets.

More bending...

The brackets are shaped like a rectangular 'J'.

The Brits call it "al-oo-min-ee-um".

Bend it...

Smash it...

Throw in some heating elements and ya got yourself a heater for the winter too!

3/4" electrical conduit used to hold the heater box above the vacuum box. Pardon the messy shop. Next project, "Operation Declusterfication!"

From below.


Fully assembled and operational. Unfortunately, the two heating elements are not enough to efficiently heat up the plastic to the proper temperature, so two more heating elements were later installed.

The ribs and parabolic reflectors proved to not work as efficiently as anticipated. They were removed and the entire interior of the oven box was lined with the aluminum. 3/4" wide steel flats were installed to serve as the brackets for mounting the four heating elements. The heating elements used were purchased from

Sample of the table's capability. This is a 1 square foot piece of HDPE.

 The other side.

I grabbed a bowl to test plexiglass.

The table is able to use 2' x 2' sheets of plastic. But for smaller shapes, I made this stencil to hold 1' x 1' pieces to conserve material.

Plexiglass is not the easiest plastic for forming. This picture shows the first test in which it didn't get hot enough. Thus, it didn't conform fully to the shape. The second test was bizarre. By the time it got to its glass transition temperature, it was sagging severely. The excess surface area turned into webbing, which was cool looking, but wasn't representative of the shape. The second piece shattered when being removed from the stencil, thus the lack of a picture.

Tests were performed using:
1/8" HDPE (High Density Polyethylene) - turns kinda gooey
1/8" Plexiglass (Acrylic) - tends to bubble and sag excessively
1/16" and 1/8" HIPS (High Impact Polystyrene) - perfect for vacu-forming
1/16" and 1/8" PETG (Transparent Polyethylene) - good for vacu-forming and it's transparent


  1. What is the base metal, with all the holes in it, and where would I get it, and it name if you dont mind saying... it looks like a metal vent plate for heating and air venting...

    1. My apologies for the late response. That's a 1/16" thick piece of perforated stainless steel. The holes are 3/16" diameter spaced at 1/4" apart hexagonally. I bought it at Lowes.

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