I use to work in orthopaedics/artifical limbs/etc so I have lots of exposure to vacuum forming. One thing we did on smaller casts of amputed limbs, feet, etc was wrap them in industrial nylons. This would allow vacuum to get into every crack and crevice so there wouldn't be any air pockets. On Larger casts such as a whole back brace we'd insert a large 4" pipe covered in vaseline so we could rotate the cast while we worked on it.

Well one day we ran out of supplies, so there I was running across to the department store to buy their entire supply of white nylons and three jars of vaseline. Trying to explain to the cashier did no good. I've never shopped there since!


Anyways, I'm going to use this occasion to show how to make yourself the most confortable pair of 'MODDED' insoles.

-Buy the softest foam you can that's used for making flower arrangements. (Some brands are too stiff... I bought mine from a dollar store)
-Cut in half. They're too thick.
-Place in box so they don't wander when you step on them.
-When stepping down, realize this foam is more dense then the stuff they
really use so you might have to make sure you put enough pressure down.
-Next pound the area where the toes are... you want this flat. (Toes are suppose to wiggle, not be held confined.)

-Mix up some plaster and pour it into the molds.

-Once hard, break the foam off.

-Shape using a body-filler file.
-Smooth out using a piece of screen (the stuff for keeping bugs out) and some water.
-Note: It's allot easier to take plaster off then to add it.

-Build a box with a false bottom. Hook up a vacuum to compartment underneath. Drill holes to let vaccum through.
-Using a piece of plywood similiarly shaped as the mold will help get a good
vacuum on it.
-Put 1st layer of craft foam on a sheet. (I've also used larger insoles and trimmed them once done, but found they shrink and get slightly harder.) Heat 1st layer in oven. (Old toaster ovens can sometimes be big enough for this.)
-Put 1st heated layer on mold, with vacuum going, cover top of box with a
garbage bag. It'll pull the foam down.
-Let cool, don't remove.
-Glue and heat up a second sheet if one isn't thick enough. You might also have to glue pieces to fill in the arch area.

-Once done, I use an existing insole and a pen to trace out the shape. Cut excess off with knife. A bench grinder would be great, but I've used my belt sander turned upside down to grind edges down.

As with any foot product, if you suffer from bad blood circulation, diabetic, etc... a foot infection, calluses, ulcers, etc an lead to problem such as amputation. If it rubs, don't wear it.