1. PLASTICS; a Brief overview.
a. Thermoforms.
Acrylics, Polycarbonates, ABS, Styrene,
Vac-forming, Drape forming, compression forming, bending,
Walls for molds
Solvent bonding
b. Thermosets
Urethane resins, 36-xxx, ptmw 8949-8, BJB line of elastomers and hard resins
Polyester resins, Epoxies
Additives Like cabosil, glass micro-spheres, Calcium carbonate.
c. Foam boards. Thick (2-4") sheets used for tooling and prototypes
Foaming urethanes. Pour Foam- 2-part liquid that foams to 3 times it's size
Ren board, styrafoam,
d. Solvents and glues; Ridout plastics
Methylene chloride(Weld-on 3 or 4),MEK (Methyl ethyl ketone), Tetrahydrafurane(THF)
Filled glues, Weld-on 16(syrup-like glue for acrylic and Polycarbonate), pvc pipe cement.
Five minute epoxies, West system epoxies.
Bondo, hot glue, rubber bands and string?
e. Molding compounds
Clay (Non-hardening Plasticene)
Silicone RTV (Tin based or Platinum based)
REPRO (2 part 1to1 filled urethane, good for hard tooling,) and other hard cast resins.
Plasters and cements
2. Shop casting equipment and tools
a. Accessories (Hand tools and expendables.)
scales for mixing ratios.
syringes (reliefs, frames?)
b. Pressure Pots(dangerous if not careful!)
Heat bands for faster cures,
different sizes for paint cans,
c. Vacuum pumps and chambers.
also dangerous if not careful.
Vaccuum lids need to be very thick."> - see page for warnings.
3. TYPES OF PARTS
a. Solid backed (one sided mold)
Detail or skinning parts
Logo or wall mounting sculpture (reliefs, frames?)
b. Thin wall, hollow parts (two part mold-inside and outside)
Model kit type
Shell-like parts,
c. Figural sculpture or posed character
Separate parts (arms, legs, articulated.)
Full character- needs critical parting line established
d. Complex parts (oh-oh!)
Extreme negative draft interior or exterior
Lots of holes or pass throughs
Odd Projections or thin oblique angled arms
4. TYPES OF MOLDS
a. One sided open pour
Multiple varying parts possible.
Hard backing plate can be applied
Time to manually poke out bubbles or tilt and rock to ‘skin’ a thin wall
b. Two-half feed and vented.
Single pour (sliced parting line)
2 pour (established parting line)
Mastered halve hard casts for repeating molds
c. Locating the halves.
Half parting line. Usually to the back of figure
Full parting line (2 halfs with locators and shell if needed)
d. Complex molds .
Dummy blocks to take up volume or help location. (Large molds)
Multiple pins or items like screw inserts, (hardware capture),
Suspended inclusions like extra weight, internal skeleton, reinforcing items
5. Molding quirks
a. Mold life (20-30 part)
Talcum powder
Barrier coats (spray primer, Pouring or brushing flash coat.
Releases (silicone, PTFE, Stearate powder,)
Cleaning and care (tlc)
b. Reservoirs and delivery systems.
Gravity feed
Syringe, or other screw based pump,
Verticle surface venting, controlled flash venting, edgemounted strips
Cup or cone reservoirs
c. Heat and pressure.
Heat means fast, fast means hurry, hurry leads to suffering...
A pressure pot is your dangerous friend that makes it so much better.
Additives can give you a light foaming action.
6. Contacts and Suppliers
a. Freeman MFG & Supply Releases, tooling resins, Repro-line
1101 Moore Rd. Avon, Ohio 44011
440-934-1902 800-321-8511 Fax 440-934-7200 www.freemansupply.com
b. Vagabond Corporation Model-Cast 36xxx urethane + supplies General purpose resin
PO Box 39 Warner Springs, CA 92086-0039
760-782-3136 Fax 760-782-3138. www.vagabondcorp.com
c. PTM&W Industries Resins and supplies (8949-8948 urethanes)
714-734-8450 Fax 714-734-8929
d. Micro-Mark The ‘everything modelmakers need’ catalog
www.micromark.com
e. Walco Materials Group Silicones, resins, releases, BJB line of resins.
www.walcomaterials.com (5.7 MB mold-making guide PDF on site)
2121 Chablis Court #100 Escondido, California 92029
760-520-1020 800-297-4541 Fax 760-520-1025
I would like to thank the people for attending my seminar at 2005 San Diego Comic-con.
The feedback I recieved was much appreciated and has inspired me to continue with casting
and mold-making educational projects. Please feel free to
E:mail me with comments or questions about the seminar.
Please check this site often for news
on upcoming seminars and projects.
I would also like to thank;