PT4151 Versatile Epoxy Casting Resin


PT4151 is a medium viscosity, easily poured epoxy casting resin specifically formulated to provide a non-galling, self-lubricating cured surface. PT4151 contains a special blend of non-metallic fillers that provide easy mixing and handling, low shrinkage and special cured properties. This resin is ideally suited for metal forming operations as well as a variety of general tooling uses. PT4151 has been designed to be virtually non-settling when stored under moderate temperature conditions. If the resin is quite old, or if it has been exposed to higher than normal temperatures, it should be stirred before use as a normal precaution.

As PT4151 is an economical resin, it has been used extensively as a tooling backup resin, with the incorporation of a variety of bulk fillers. The mixed viscosity of the system is sufficiently low to allow the addition of large quantities of sand, aggregates or other clean, dry bulk fillers to provide low-cost tool backing.

Part A
Part B
Part B1
ASTM Method
Viscosity, @77F, centipoise
140,000 cps
850 cps
700 cps
Specific Gravity, gms./cc
Mix Ratio 100 : 25 By Weight**PTM&W
Pot Life, 4 fl. oz. Mass @ 77F
 100 : 26 By Weight**

** These are variable ratio hardeners that will provide good cures over a wide ratio range. The optimum ratio range for these hardeners is 20% to 30%. In this range, the highest cured hardness and best physical properties are obtained. Increasing the amount of hardener will lower the final cured
hardness and increase the flexibility of the casting.


When using PT4151 with Parts B or B1, the material will cure completely at room temperature. The amount of time to cure will depend upon shop temperature, thickness of the casting and the insulating properties of the pattern/mold material. PT4151 Part B hardener is recommended for medium sized castings and for instances where bulk fillers are to be incorporated. PT4151 Part B1 hardener is intended for larger solid mass castings. The cure times for PT4151 were determined with 1000 gram mixtures cast into metal quart cans at 75oF ambient temperature. Under these conditions, PT4151 Part B required 24 hours, and PT4151 Part B1 required 48 hours to reach full properties.

 Gallon Kit
Pail Kit
PT4151 Part A
11 lb.
30 lb.
PT4151 Part B
2.75 lb.
7.5 lb.
PT4151 Part B1
2.9 lb.
8 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.

 PT4151 A/B
PT4151 A/B1
ASTM Method
Mix Ratio, By Weight
100 : 25
100 : 26
Mixed Viscosity, @77F Centipoise
6,500 CPS
6,000 cps
Pot Life, 4 fl. oz. Mass @ 77F
2 hours
5 – 6 hours
Cured Hardness, Shore D
85 Shore D
84 Shore D
Shrinkage, in./in., Mold #2, Vol: .344 gal
Specific Gravity, grams, cc
Density,             lb./cu in. , lb./cu gallon
.0485, 11.2
.0474, 10.9
Specific Volume, cu. in./lb.
Tensile Strength, psi 9,200 psi8,900 psi
Flexural Strength, psi
13,500 psi
11,500 psi
Compressive Strength
17,000 psi
14,500 psi


The chart below is provided to illustrate the effects of varying the mix ratio of PT4151 resin and hardeners. As is typical of the variable ratio type hardener, when the amount of hardener is increased above the optimum, the cured hardness of the casting is correspondingly decreased.


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.