PT5355 Fire Retardant Epoxy Laminating Resin


PT5355 is an epoxy laminating system with cured fire retardant characteristics that meets the requirements of the FAR 25.853 specification. Independent lab tests show that this material significantly exceeds the minimum requirements of this specification. The cured physical properties of PT5355 are quite good, and laminates made with it will give long service in the most demanding applications. It has well-balanced handling characteristics for ease of use and quick fabrication capabilities. There are two hardeners available for use with PT5355 resin for different size laminates. PT5355 Part B has a 30 minute pot life, and is intended for smaller items and patching applications. PT5355 Part B1 has a 1 hour pot life, and is intended for larger laminates. Both hardeners will cure completely at room temperature and provide very similar properties when cured. PT5355 is a good candidate for any application where tough cured properties are needed and a self extinguishing system is required.

 PT5355 A
PT5355 B/B1
ASTM Method
1500 – 2000 cps
200 – 300 cps
Specific Gravity, gms./cc
Mix Ratio, by Weight
100 : 19
Pot Life, 4 fl oz Mass @ 77°F
Part B: 30 min.    Part B1: 1 hour D2471


Both the Part B and Part B1 hardeners for PT5355 will cure completely at normal ambient temperatures (75°F nominal), and do not require an oven heat cure. Laminates made with the Part B hardener can be demolded after an overnight cure (18 hours minimum). When using the Part B1 hardener, 24 hours should be allowed before the laminate is removed from the pattern. Higher ambient temperatures will shorten these requirements, and conversely, longer cure times will be necessary in colder temperatures.


Gallon Kit
PailDrum Kit
PT5355 Part A 9 lb.
42 lb.
450 lb.
PT5355 Part B/B1
1.75 lb.
8 lb.2 @ 43 lb. ea. (86 lb.)
Kit10.75 lb.
50 lb.
536 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.

 PT5355 A/B/B1
ASTM Method
Mix Ratio, by Weight
100 : 19
Mixed Viscosity, @77°F, centipoise
900 – 1000 cps
Pot Life, 4 fl. oz. Mass @ 77°F
Part B: 30 min.
Part B1: 1 hour
Cured Hardness, Shore D
88 Shore D
Shrinkage, inch/inch
Part B: .0005
Part B1: .0003
Specific Gravity, grams, cc
Density, lb./cu. inch
Specific Volume, cu. in./lb. 23.3
 Cast SampleLaminate* 
Tensile Strength, psi
7,273 psi
45,775 psiD638
Elongation at Break, %1.26 %
1.5 %D638
Tensile Modulus, psi
624,274 psi
2,754,557 psi
Flexural Strength, psi 12,346 psi
59,437 psiD790
Flexural Modulus, psi 
668,455 psi
2,894,587 psiD790
Compressive Strength, psi
11,265 psi
Compressive Modulus, psi 455,294 psi
Izod Impact Strength, Method A, Notched
Glass Transition Temp.,  DMA  Tg, 
127°F D4065
Heat Deflection Temperature, @ 264 psi136°FD648
Coefficient of Thermal Expansion,
Range 50°C to 100°C
8.22 x 10-3 in./in./°F

*These properties were derived using a 1/8″ thick laminate, Style 181 fiberglass cloth, with a 45% resin content.


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.