| |
| Pourable
Polyurethane Mold Rubber |
 |
74 Series
& 75 Series RTV Liquid Rubbers
Features
 |
- Pourable
or Brushable
- Very
hard to very soft grades
- Lowest
cost of any mold rubber
- Easy,
1:1 mix grades
- Excellent
cured shelf life
- Low
shrinkage grades
- No
plaster build-up
|
Description
|
These
popular products are made of liquid Part A and Part B, which
after mixing, cure overnight at room temperature to flexible,
high strength RTV mold rubbers.
|
Uses
|
They
make long-lasting, easy releasing molds for casting gypsum plasters
and waxes without release agents. They are also excellent for
casting cement and resins of epoxy, polyester, urethane and
acrylic with proper release agents. Poly 75 Series economy mold
rubbers have been prepared for good economy with elevated performance.
Poly 75-60 rubbers may produce staining of some casting materials.
Molds may shrink after extended use. The final properties are
not affected by the varying color of Part B.
Part
C for Softer Molds: Part C Softener may be added to these
products to soften the cured rubber and lower the viscosity
of the mix. When Part C is used, there will be a loss of strength,
slower cure and increased tendency to shrink after repeated
castings. In order to soften Poly 74-30 to a Shore A-15 hardness,
add one part C to one part A plus one part B, by weight. The
amounts necessary to soften products will vary and should
be established by conducting tests. |
UV-Additive
For Improved Exterior Exposure
|
When
thoroughly stirred into Poly Urethanes, UV liquid additive improves
exterior durability and greatly reduces surface degradation
caused by sunlight and UV light sources. Use at 0.5% of the
total weight of the liquid mix before curing. Carbon black thoroughly
dispersed at levels of 5% also improves exterior exposure considerably.
Available in 4 oz. and 1 lb. bottles. |
Thickening
for Brush-On Molds:
|
74
Series rubbers may be thickened with Cab-O-Sil (See Accessories). |
Physical
Properties: |
|
74-55 |
74-45 |
74-44 |
74-40 |
74-30 |
Clear
74-30 |
74-29 |
Mix
ratio, by weight |
4A
to 1B |
1A
to 1B |
2A
to 1B |
2A
to 1B |
1A
to 1B |
1A
to 1B |
1A
to 1B |
Hardness,
Shore A |
55 |
45 |
45 |
40 |
30 |
30 |
30 |
Pour
time |
15
min. |
30
min. |
20
min. |
20
min. |
30
min. |
30
min. |
60
min. |
Color |
Clear
yellow |
Gray |
Gray |
Translucent
blue/gray |
Amber |
Clear
amber |
Black |
Viscosity,
mixed |
4,000
cps. |
2,500
cps. |
3,500
cps. |
3,400
cps. |
2,000
cps. |
3,400
cps. |
2,800
cps. |
Cubic
inches/pound |
27.5 |
27.5 |
27.5 |
27.5 |
27.5 |
27.5 |
27.5 |
Shrinkage
during cure |
Nil* |
Nil* |
Nil* |
Nil* |
Nil |
Nil |
Nil |
|
|
|
|
|
|
|
|
|
75-80 |
75-75 |
75-70 |
75-60 |
75-59 |
|
|
Mix
ratio, by weight |
2A
to 1B |
2A
to 1B |
1A
to 1B |
1A
to 1B |
1A
to 1B |
|
|
Hardness,
Shore A |
80 |
75 |
70 |
60 |
60 |
|
|
Pour
time |
45
min. |
20
min. |
40
min. |
10
min. |
10
min. |
|
|
Color |
Yellow/
Amber |
Amber |
Gray |
Amber |
Amber |
|
|
Viscosity,
mixed |
5,000
cps. |
4,000
cps. |
3,000
cps. |
1,200
cps. |
2,500
cps. |
|
|
Cubic
inches/pound |
26 |
26 |
27 |
27 |
27 |
|
|
Shrinkage
during cure |
Nil* |
Nil* |
Nil* |
Nil* |
Nil* |
|
|
|
|
|
|
|
|
|
|
*
In large masses rubber may become slightly warm and some thermal
shrinkage may occur on cooling.
Part B's of 74-40, 74-30 and 74-29 require stirring before
use. |
Packaging: |
|
Containers |
|
|
Size |
Net
lbs. |
Product |
Weight/lbs. |
A |
B |
A |
B |
74-29,
74-30, Poly 75-59, 75-60, 75-70
Mix
Ratio
1A to 1B |
4 |
1
qt. |
1
qt. |
2.0 |
2.0 |
16 |
1
gal. |
1
gal. |
8.0 |
8.0 |
80 |
5
gal. |
5
gal. |
40.0 |
40.0 |
900 |
55
gal. |
11x55
gal. |
450.0 |
450.0 |
|
|
|
|
|
|
74-40,
74-44, Poly 75-75, 75-80
Mix
Ratio
2A to 1B |
6 |
2
qt. |
1
qt. |
4.0 |
2.0 |
24 |
2x1
gal. |
1
gal. |
16.0 |
8.0 |
120 |
2x5
gal. |
5
gal. |
80.0 |
40.0 |
675 |
55
gal. |
30
gal. |
450.0 |
225.0 |
1,350 |
2x55
gal. |
55
gal. |
900.0 |
450.0 |
|
|
|
|
|
|
74-55
Mix
Ratio
4A to 1B |
5 |
2
qt. |
1
pt. |
4.0 |
1.0 |
20 |
2x1
gal. |
1/2
gal. |
16.0 |
4.0 |
40 |
5
gal. |
1
gal. |
32.0 |
8.0 |
100 |
2x5
gal. |
2
1/2 gal. |
80.0 |
20.0 |
562.5 |
55
gal. |
15
gal. |
450.0 |
112.5 |
|
|
|
|
|
|
|
74
Part C Softener: 1
pint (1.0 lb.), 1 gal. (8.0 lbs.), 5 gal. (40.0 lbs.) |
|
