Product Specifications: PC2021AB

Tough-Seal 21 is a tough and durable fast gelling Potting Compound and Sealant with excellent Thermal Cycling Stability. This medium viscosity material is self-leveling and flows like honey around electrical components to ensure complete coverage of your entire PCB or electronic assembly.

Tough-Seal 21 has a faster 10-20 minute working time and a Shore Hardness of 64A, which is similar to the hardness of a car tire. Tough-Seal 21 reaches 94% of its full hardness after an overnight cure or with a heat cure of 1 hour at 80°C (176°F). Tough-Seal does not exotherm or shrink during curing, therefore there is no embedment stress induced on the electronic components that could cause damage and failure of the PCB or electronic assemblies. Sensitive electronics can be potted safely with low embedment stress Tough-Seal.

With a high elongation of 225% when fully cured, Tough-Seal 21 maintains exceptional flexibility and thermal cycling stability from –40°C to 150°C (-40°F to 302°F) without pulling back, wilting, or cracking. This ensures a tough seal that will stop moisture or other contaminants from damaging sensitive PCB’s and electronics.

Tough-Seal has very aggressive adhesion to aluminum, making it a perfect choice for potting aluminum housings in LED lighting applications. Tough-seal bonds extremely well with most polymers. For housing and wire insulation materials that are exceptionally difficult to bond to, we offer our KEY PR1200 PRIMER, an aggressive adhesive promoter that is simple to use.

Product Information Bulletin (PIB) and Safety Data Sheet (SDS) Downloads

PIB (PC 2021AB)

SDS (PC2021A)
SDS (PC2021B)

PIB (Key PR1200 Primer)
SDS (Key PR1200 Primer)

(Typical Properties)

	Physical Properties
	Color, Part A	Off White
	Viscosityat 25°C, cP, Part A, (RVT #5, 20 RPM)	7,000
	Specific Gravityat 25°C, Part A	1.32
	Densityat 25°C, lbs/gal, Part A	11.0
	Color, Part B	Black
	Viscosityat 25°C, cP, Part B, (RVT #5, 20 RPM)	11,000
	Specific Gravityat 25°C, Part B	1.28
	Dielectric Constant,25°C – 60 Hz	5.75
	Dissipation Factor, 25°C – 1 MHz	0.026
	Dissipation Factor, 25°C – 1 kHz	0.028
	Dissipation Factor, 25°C – 60 Hz	0.064
	Heat CapacityCp, 25°C, J/g°K	1.37
	Thermal Conductivity,25°C, W/m°K	0.26
	Coefficient of Thermal Expansion, ppm/ °C
	(-) 65°C to 75°C	135
	75°C to 100°C	0
	100°C to 150°C	75
	Coefficient of Thermal Expansion, ppm/°F
	(-) 85°F to 167°F	75
	167°F to 212°F	0
	212°F to 302°F	42
	Hardness vs Temperature
	(-75°C / -103°F)	88 A
	(-25°C / -13°F)	75 A
	5°C / 41°F	69 A
	25°C / 77°F	64 A
	50°C / 122°F	62 A
	66°C / 150°F	61 A
	80°C / 176°F	62 A
	100°C / 212°F	57 A
	120°C / 248°F	51 A
	150°C / 302°F	47 A
	Hardness vs Ambient Cure Time
	1 hour	15 A
	2 hours	26 A
	4 hours	31 A
	8 hours	35 A
	12 hours	35 A
	1 day	39 A
	2 day	46 A
	3 days	52 A
	4 days	57 A
	1 week	60 A
	1 month	68 A
	Mechanical Properties
	Tensile Strengthper ASTM D638, 25°C, PSI	450
	Elongationper ASTM D638, Type I, 0.125 in, 25°C	225%
		Co=Cohesive Ad=Adhesive
Tensile Lap Shear Strengthper ASTM D1002, 25°C, psi **
	Aluminum Bare	540 Co
	Steel Bare	530 Ad
	Steel Ground	480 Co
	Primed Steel	530 Co
	Galvanized Steel	560 Co
	Tin Plated Steel	470 Co
	Chrome Plated Steel	560 Co
Tensile Lap Shear Strengthper ASTM D3163, 25°C, psi **
	FRP – Polyester Fiberglass	540 Co
	Garolite G-9 Melamine/Glass	530 Co
	Garolite G-10 Epoxy/Glass	550 Co
	Garolite XX Phenolic/Paper	570 Co
Tensile Lap Shear Strengthper ASTM D3163, 25°C, psi **
	Acrylic	560 Co
	Acrylic/PVC	430 Co
	PVC – Polyvinyl Chloride	530 Co
	CPVC – Chlorinated PVC	660 Co
	ABS – Acylonitrile Butadiene Styrene	500 Co
	PETG – Polyethylene Terephthalate	610 Co
	Lexan – Polycarbonate	520 Co
	Nylon 6/6 – Polyamide	520 Co
	Polypropylene	50 Ad
	Polyethylene LDPE	20 Ad
	Polyethylene HDPE	40 Ad
	Teflon PTFE – Polytetrafluoroethylene	40 Ad
	Noryl – Polyphenylene Oxide/Polystyrene	220 Ad
	Ultem – Polyetherimide	540 Co
	**20 mil Bondline, 1 in x 4 in Adherands, 1 in Overlap