By: Alex Brett, R.T.O.(c)

 Prosthetic foot shell or life cast  40 Durometer urethane  Urethane pigment  25 lb/cu ft. Flexible urethane foam  Replicator silicone  5 Durometer silicone  Cast sealer  Mixing cups  Mixing sticks  1” Disposable brushes  1oz Felt, Nylon stockinette  Renia PUR primer  Aquaseal adhesive and leather for sole

 When working with urethane foams and rubbers: always wear gloves and assure there is adequate ventilation (or use a suitable respirator). Avoid contact with skin.  If you are ever unsure of a material, consult the MSDS prior to using.  *All the products used in fabrication of this partial foot are completely safe as long as they are used properly and with care.*

 We will start by fabricating 2 negative molds of a prosthetic foot shell or a life cast.  1 with Renew materials silicone replicator  1 with Renew materials 5 durometer silicone

 We will now seal the cast, pigment the urethane and brush on four layers. A nylon should be added for reinforcement on the fourth layer.

 We will now scuff the surface of the socket, and fit it into the replicator mold. After that we will pour 25lb flexible foam into the mold to create a basic foot shape.

 Once the foam has cured, we will demold, clean up and reduce the overall thickness of the forefoot by approximately 1 cm.

 We will then brush 3 more coats over the socket and foamed forefoot to encapsulate the foam.  This foam is used so that the foot will be lightweight yet still flexible. Pure urethane can be used but this will result in a very heavy partial foot.

 We will now take the 5 durometer silicone negative, pour urethane into it, and pull it over the foot to give the finished piece a high definition appearance

 Once the urethane has cured, demold the foot and smooth the transition with a 180X cone.

 Rotate 1 final layer of urethane (minus the toes) to seal the transition up.

 It is best to post cure in the 50C for 4-6 hours. This will assure the urethane is fully cured and acheives maximum strength.

 We will then buff the exterior with 320X sandpaper to take the shine off.

 Remove foot from cast and trim as desired

 Your foot is now ready for a test fitting!  Urethane can be can cut and modified easily with scissors, and a 180X sanding cone.

 Always fabricate partial feet 1 size under sound side. They tend to appear larger, so 1 cm under sound side is usually well received.  Aquaseal adhesive can be used to repair or glue a sole to your urethane partial foot.  Renia PUR primer works great to prep urethane surfaces that have cured fully between steps.