Transcript of By: Alex Brett, R.T.O.(c). Prosthetic foot shell or life cast 40 Durometer urethane Urethane...
- Slide 1
- By: Alex Brett, R.T.O.(c)
- Slide 2
- 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
- Slide 3
- Slide 4
- 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.*
- Slide 5
- 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
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- 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.
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- 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.
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Once the foam has cured, we will demold, clean up and reduce
the overall thickness of the forefoot by approximately 1 cm.
- Slide 26
- Slide 27
- Slide 28
- 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.
- Slide 29
- Slide 30
- Slide 31
- 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
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Once the urethane has cured, demold the foot and smooth the
transition with a 180X cone.
- Slide 36
- Slide 37
- Slide 38
- Rotate 1 final layer of urethane (minus the toes) to seal the
transition up.
- Slide 39
- Slide 40
- It is best to post cure in the oven @ 50C for 4-6 hours. This
will assure the urethane is fully cured and acheives maximum
strength.
- Slide 41
- Slide 42
- We will then buff the exterior with 320X sandpaper to take the
shine off.
- Slide 43
- Slide 44
- Remove foot from cast and trim as desired
- Slide 45
- Slide 46
- Slide 47
- Your foot is now ready for a test fitting! Urethane can be can
cut and modified easily with scissors, and a 180X sanding
cone.
- Slide 48
- 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.
- Slide 49
- Slide 50