Materials
Resources / Boston-centric
Kelly Heaton, 1999-2001
kelly@media.mit.edu
index
Acrylic (lasercutting, machining):
Commercial Plastic / Mr. Plastic: 352
McGraff Hwy in Sommerville (MA). Stock acrylic for use
on a laser cutter. Other plastics include lexan for machining and thermoforming
materials. Mr. Plastic also stocks glues, sratch remover etc.. for acrylics.
J. Freeman (Dorchester). Only sells 4 x 8 foot sheets, but has the best
selection in the Boston area.
McMaster Carr is good for small sizes of sheet plastics, among many other
things. http://www.mcmastercarr.com/
Solter Plastics, Inc. (310) 473-5115; (310)-478-5228. Located in Los
Angeles, this place has an enormous selection of plexiglass colors (request
a sample box for ~$30). Also makes custom colors.
Industrial Plastic Supply:
212-226-2010;
309 Canal Street NYC
Canal Plastics Center: 212-925-1032;
345 Canal Street, NYC
Sheet
plastics (thermoforming):
Mayfield Plastics: Phone:
508-754-3476. Contact: Ron Gaulin. HDPE: Heat the sheet plastic in an 800-900
degree F oven for approx 70 seconds. This time will vary from oven to oven,
and depends upon the material thickness. .060 thickness works best, but .030
will also form well if you heat it properly. The plastic should be removed from
the oven at the precise moment that it becomes clear - no longer! The melting
temperature of HDPE is 325 degree F. If the material begins to sag, buckle or
bubble, it will not form well. Evidence of stretching may indicate that the
material has been overheated; if the material does not pull neatly into place
during vacuum forming then it is likely too cool. It is far preferable to heat
the material quickly in a hot oven than slowly in a cooler environment. For
best results, make sure that the mold is warm prior to forming (i.e. 130 degrees
F) - this can be achieved with a blow torch, or by forming several sheets of
.060 HDPE and allowing them to cool on the mold. Be aware that HDPE will shrink
considerably when it cools, and can stick to some molds, especially if the mold
is textured. An alternate material to HDPE that thermoforms easily is PETG.
Patriot Plastics: 16 Fowle Street in Woburn, MA. Phone: 781-935-3990.
They carry sheet HDPE and LDPE in .020, .030 and .060 inch thicknesses.
Plywood:
Boulter Plywood (Sommerville): 1/8" Okume is especially good
for bending and laser-cuts well.
Rubber
stock:
Greene Rubber:
Phone: 781-937-9909. Carry stock rubber tubing, o-rings, sheet rubber, etc...
O-rings:
American Seal, Inc.
http://www.americanseal.com
Contact: Jody.
phone: 713-675-7325. Purchase orders or COD only.
Casting
resin:
Hapco; contact:
Robert Hale; phone: 781-826-8801; purchase orders or COD only
- amber colored
polyurethane: Hapflex 666. Works great with the Pearl-Ex dry pigments, but yellows
with time and exposure to UV.
- white resin: Ultraloy 50 - dries to a hard, mostly opaque white (tint with
Hapco white for a pure, opaque white).
Hapco also carries
both opaque and transparent dyes for tinting casted resins and rubbers (see
"pigments for tinting polyurethane," below).
Polytek Development Corporation offers
a variety of resins and rubbers, plus a useful catalogue full of samples (cost:
$10). http://www.polytek.com/
Epoxy:
System 3 epoxy, glass microspheres,
thixotopic powder, etc:
Merton's Fiberglass Supply,
413-736-0348 (Joe Merton. See
also Walter
Black -- for custom body work. (413) 543-1857). System 3 epoxy manual is
an excellent guide to boatbuilding technique (avail. for purchase thru Merton's.)
Stone Auto Body Supply: Rich
Carlson, Manager. One of several suppliers for the auto body industry in Cambridge
area.
Casting rubber:
Smooth-On polyurethane
rubber ( see mold-making materials) is easier to work with in terms of curing
time and air bubble removal, but the color is a translucent brown (= coloring
options are limited).
Hapflex 766: This
polyurethane resin cures to a hard , colorless rubber. (65A durometer). The
gel time is 10 minutes, so air bubbles must be removed quickly using a vacuum
chamber. The rubber does not fully cure for nearly a week, although the curing
process may be accelerated by heating - an 80 degree C oven for four hours was
recommended by the manufacturer (but be careful to avoid heating at a higher
temp, b/c the material will burn).
Clear silicone rubber (medical grade): avail. through
Applied Silicone Corp: http://www.appliedsilicone.com
Phone: 805-653-5638
Rubber specs: 5000062
liquid silicone, durometer: 25, 30 or 40. The mixture I tested was 10:1 (part
A to part B); price: $12.60 per gallon.
NOTE: This mixture
takes several days to cure. Air bubble removal can be a real pain unless you
have a high-powered vacuum or have the time to leave it under vacuum for awhile.
The longer curing silicone would probably be fine if vacuumed for an hour or
so (it's super-viscous and full of bubbles when you first mix it).
See also (under
casting resin):
Polytek Development Corporation:
http://www.polytek.com/
Mold-making materials:
Smooth-on:
http://www.smooth-on.com
(they won't sell
direct; Boston-area distributor is Waldo Brothers: 445-3000.) Smooth-On (grey)
silicone mold-making material: avail. at Pearl Paint. Easy to pour (low air
bubbles) but rigid and succeptible to cracking. Mold lifetime: approx. 10 castings.
Smooth-On polyurethane rubber for casting is also good, but needs a release
agent (Smooth-On Universal Mold Release). Polyurethane rubbers are also stiffer
and more succeptible to tearing than silicone. The most flexible of the Smooth-On
silicones (used in the colored-light objects) is Smooth-Sil 912. Air bubbles
are a problem - use a vacuum chamber prior to pouring. In general, I found that
a two part mold made from half silicone and half polyurethane worked well- the
silicone is good for parts which require significant flexibility during demolding,
and the urethane makes a good, firm counterpart.
See also (under casting resin):
Polytek Development Corporation: http://www.polytek.com/
Pigments for tinting polyurethane resin (and some rubbers*):
Note:
Adding pigment at or below 3-4% of total mixing weight does not require alteration
of resin proportions (A to B); however, any additonal pigment will require adjument
of the proportions - consult the manufacturer.
Hadco (781-826-8801):
carries a variety of non-flourescent colors in both transparent and opaque dyes.
Pearl-Ex powder pigments
(non-toxic, non-conducting).
Avail. at Pearl
Paint (Cambridge): 547-6600; or NYC: 212-431-7932
Also avail. by
calling: 800-442-0455, or 707-433-9577 (this is their distributor; ask for a
color chart)
Pearl-Ex powders work great in Hapflex 666 (polyurethane resin), but not so
great in urethane rubbers - it gets sticky.
Plasticolor: pigments (esp. flourescent) for dying resin and other chemicals
http://www.plasticolors.com
Plasticolor phone: 440-997-5137
Day-Glo Color Corporation: specializes
in flourescent yellow dyes and pigments. http://www.dayglo.com/
BASF Corporation: huge
chemical supplier; good for intense pigments. http://www.basf.com/index.html
* Be careful to test colorants in a small sample first, as certain materials
take pigments better than others. Too much pigment will cause the material to
cure improperly.
Apex Resources Inc: Distributor
of mica powders. Contact: Vinita Gupta; e-mail: apexr@bellsouth.net;
Phone: 502-326-3118
Metal
Powders:
Atlantic Equipment Engineers: 800-486-2436;
http://www.micronmetals.com/index.htm
United States Bronze Powders, Inc.:
Brass, nickel silver, bronze and copper powders for use in cold casting.
Phone: 908-782-5454
For conductive silver powder: see
also, Progressive Fillers International, Incorporated (Micaclad conductive silver)
Oil Paint:
Williamsburg. Hand-made
paints are avail. through Pearl Paint in NYC (212-431-7932),
or direct (phone #?).
General
Arts and Crafts:
MassArt:
232-1555 / store: 739-4770
School of the Museum of Fine Arts: 267-6100
Utrecht Arts and Crafts:
262-4948
Pearl Paint (Cambridge):
547-6600
Waldo Brothers (Boston distributor for Smooth-on products): 445-3000;
contact: Gary Cook
Mr. Plastic (Sommerville) (see
sheet plastic / rubber)
Altech Plastic
(South Boston - they also have full machining capabilities)
Pearl Paint (NYC):
212-431-7932