PT4935 Aluminum Filled High Temperature Casting Resin


PT4935 is a gray, aluminum filled epoxy resin that can be used for a wide variety of applications where good heat resistance is required. It has a relatively low viscosity, so it mixes and pours easily, and duplicates details very well without trapping air or leaving surface porosity. The aluminum filler in PT4935 makes it easy to machine when cured. This resin has been especially formulated to be virtually non-settling in long term storage. PT4935 provides accurate, dimensionally stable molds and tooling with very high physical properties. These features make PT4935 an ideal choice for constructing vacuum form molds, compression, injection and blow molds, stretch dies, low production dies; bonding, molding and
nesting fixtures, patterns and core boxes, RTM tooling, general repairs and backup for metal sprayed surfaces. PT4935 utilizes the latest material technologies, it contains no hazardous classified or restricted ingredients, for improved safety in the work place.

PT4935 can be used with Part B hardener for smaller castings and where a faster cure is needed. Part B1 hardener has a longer pot life for slower cures and less shrinkage. The longer pot life allows ample time to add aluminum needle bulk filler if desired for cost savings and lower shrinkage in larger masses. Part B2 hardener has a very long working time that will allow the casting of larger masses without bulk fillers.

 PT4935 A
PT4935 B
PT4935 B1
PT4935 B2
ASTM Method 
72000 cps
1700 cps
150 cps
200 cps
Specific Gravity, gms./cc
Mix Ratio, by Weight

100 : 9.5
100 : 12
Pot Life, 4 fl oz Mass @ 77°F
40 – 50 min.
2.5 – 3.5 hr.
8 – 12 hr.


Castings made with Part B or Part B1 hardeners will gel hard at room temperature, and the castings can be demolded for further curing if desired. Care should be taken if the castings are to be demolded before post curing, as high temperature service hardeners typically give somewhat brittle cures at room temperature only. This is not as much a concern with Part B, but a definite consideration with Part B1. Hardener Part B2 is a very slow curing hardener, and castings made with it should be cured entirely on the master pattern. Castings using Part B should be allowed to cure at room temperature on the pattern for a minimum of 18 hours before post curing. Hardener Part B1 will require a 24 hour minimum room temperature cure on the pattern before post curing. Hardener Part B2 will require longer than 24 hours before post curing, the exact time being determined by the size of the casting and the amount of any bulk filler content.

An oven post cure is recommended for all castings for the maximum stability in service. A typical cure cycle would be: Gel for the required time at room temperature, plus 3 to 4 hours each at 150°F, 250°F and 350°F. This schedule represents the minimum recommended cure schedule. Longer time at room temperature followed by longer times at smaller incremental increases will usually result in lower shrinkage and less stress buildup in the finished castings.


PT4935 B
PT4935 A
PT4935 B1
PT4935 A
PT4935 B2
Quart Kit
3 lb.
.3 lb.
Gallon Kit
12 lb.
1.16 lb.
12 lb.
1.5 lb.
12 lb.
1.5 lb.
Pail Kit
55 lb.
5.25 lb.
55 lb.
6.75 lb.
55 lb.
6.75 lb.
Drum Kit 600 lb.
2 @ 36 lb.
600 lb.
2 @ 36 lb.

Inasmuch as PTM&W Industries, Inc. has no control over the use to which others may put material, it does not guarantee that the same results as those described herein will be obtained. The above data was obtained under laboratory conditions, and to the best of our knowledge is accurate. This information is presented in good faith to assist the user in determining whether our products are suitable for his application. No warranty or representation, however is intended or made, nor is protection from any law or patent to be inferred, and all patent rights are reserved. Before using, user shall determine the suitability of the product for his intended use, and user assumes all risk and liability whatsoever in connection therewith. In no event with PTM&W Industries, Inc. be liable for incidental or consequential damages. Buyer’s sole and exclusive remedy in such instances shall be limited to replacement of the purchase price.

 PT4935 A/B
PT4935 A/B1PT4935 A/B2
ASTM Method
ColorMetallic Gray
Mixed Viscosity, @77°F, centipoise
25000 cps
11000 cps
12000 cps
Cured Hardness, Shore D
91 Shore D
Shrinkage, in/in,.0047
(Mold #1
.53 Gal)
(Mold #3,
1.23 Gal)
(Mold #3,
1.23 Gal)
Specific Gravity, grams, cc
Specific Volume,  cu. in./lb.
Tensile Strength, psi 
7790 psi
8255 psi
8813 psi
Elongation at Break, %
1.46 %
1.82 %
2.02 %
Compressive Strength, psi
21,846 psi
21,440 psi
21,510 psi
Glass Transistion Temperature, Tg, TMA:
285°F358°F358°F D3386


PTM&W epoxy products are made from raw materials carefully chosen to minimize or even eliminate toxic chemicals, and therefore offer the user high performance products with minimum hazard potential when properly used.  Generally, the PTM&W epoxy resins and hardeners will present no handling problems if users exercise care to protect the skin and eyes, and if good ventilation is provided in the work areas.  However, all epoxy resins and hardeners can be irritating to the skin, and prolonged contact may result in sensitization; and breathing of mist or vapors may cause allergenic respiratory reactions, especially in highly sensitive individuals.  As such, avoid contact with eyes and skin, and avoid breathing vapors.  Wear protective rubber apron, clothing, gloves, face shield or other items are required to prevent contact with the skin.  In case of skin contact, immediately wash with soap and water, followed by a rinse of the area with vinegar, and then a further wash with soap and water.  The vinegar will neutralize the hardener and lessen the chances of long term effects.  Use goggles, a face shield, safety glasses or other items as required to prevent contact with the eyes.  If material gets into the eyes, immediately flush with water for at least 15 minutes and call a physician.  Generally, keep the work area as uncluttered and clean as possible, and clean up any minor spills immediately to prevent accidental skin contact at a later time.  Keep tools clean and properly stored.  Dispose of trash and empty containers properly.  Do not use any of these types of products until Material Safety Data Sheets have been read and understood.