What is Poly-Seal AF Butyl Tape?

Poly-Seal AF is an aluminum-faced, pressure-sensitive butyl mastic designed for duct joints, roof seams, and exterior sealing.

Where is Poly-Seal AF used?

It is used on HVAC ducts, metal roof seams, flashing joints, and general exterior waterproofing applications.

What makes Poly-Seal AF different?

Its aluminum foil facing provides superior UV, oxidation, and weather resistance for outdoor applications.

Can Poly-Seal AF be customized?

Yes. It can be produced in standard roll widths or precision die-cut shapes for specific applications.

What is Poly-Seal CR Butyl Tape?

Poly-Seal CR is a coating-ready butyl tape for roof seams and duct joints that can be painted or coated after installation.

Where is Poly-Seal CR used?

It’s used on metal roofs, flashing, and HVAC seams that require coating compatibility and aesthetic finishes.

What makes Poly-Seal CR unique?

Its surface accepts coatings while maintaining butyl flexibility and long-term adhesion.

Can it be painted immediately?

Allow the tape to bond to the substrate before applying coatings for best adhesion.

What is Poly-Seal PE-801?

Poly-Seal PE-801 is an HDPE-backed butyl sealant for hip-and-ridge roof sealing and flashing applications.

Where is it typically used?

It’s used in roofing joints, RV roofs, flashing corners, and other areas requiring instant waterproof sealing.

Is Poly-Seal PE-801 solvent-free?

Yes. The composition is free from asphalt and solvents for clean, long-lasting performance.

Can it be installed without primer?

On clean, dry, non-porous surfaces, primer is not required for a durable bond.

What is Poly-Seal SB Butyl Tape?

Poly-Seal SB is a 100% butyl adhesive tape used for bonding, gasketing, and sealing in HVAC and construction.

Common in HVAC joints, metal flanges, and outdoor sealing where durable watertight performance is required.

No. It bonds instantly with hand pressure and requires no curing or heat.

Can it self-heal around fasteners?

Yes. The butyl compound flows to fill gaps and seal around screws for leak-proof joints.

What is Poly-Seal TPO Butyl Tape?

Poly-Seal TPO is a butyl-based seam-sealing tape formulated for TPO and other roofing membranes requiring watertight joints.

Where is it typically used?

It is commonly used on metal roofs, HVAC curbs, skylights, RV roofs, and exterior flashing seams.

Yes. It is UV- and weather-resistant for long-term outdoor exposure.

Does it require heat or curing?

No. It forms an instant, watertight seal with hand pressure.

What is BF-1000 Silicone Foam?

An extra-soft closed-cell silicone foam for low-pressure sealing, vibration damping, and long-term environmental protection.

Where is BF-1000 used?

In lighting, HVAC, aerospace, transportation, and defense applications requiring durable flame-resistant seals.

What distinguishes BF-1000?

Low compression force, outstanding weather resistance, UL 94 V-0/HF-1 rating, and minimal compression set.

Is BF-1000 food-safe?

Yes, it complies with FDA CFR 177.2600 for indirect food contact.

Can BF-1000 have adhesive backing?

Yes, available with silicone or acrylic PSA options.

An ultra-soft, highly compressible closed-cell silicone foam for low-closure-force sealing and cushioning.

Where is BF-2000 used?

Electronics, avionics, HVAC, and aerospace applications needing minimal clamp force and long-term sealing.

How is BF-2000 unique?

Very low compression deflection, excellent UV resistance, and UL 94 V-0 rating.

Can it be die-cut or laminated?

Yes, available in sheets, rolls, and custom die-cut parts.

A medium-firm closed-cell silicone foam for industrial sealing, moisture resistance, and shock absorption.

Where is HT-800 used?

In enclosures, control panels, HVAC gaskets, and equipment requiring durable sealing.

What distinguishes HT-800?

Balanced density, strong resiliency, and UL 94 V-0 flame rating with wide temperature tolerance.

Can HT-800 be ordered as tape?

Yes, it is available as foam tape with various adhesive backings.

A soft closed-cell silicone foam with low closure force and enhanced sealing for electronics and transportation applications.

Where is HT-870 used?

In environmental seals for electronics, HVAC, and aerospace equipment where flame safety is critical.

What makes HT-870 unique?

Low compression deflection, minimal compression set, and UL 94 V-0 / HF-1 flame ratings.

Can HT-870 include adhesive backing?

Yes, high-temperature silicone and acrylic PSA options are available.

A soft silicone sponge providing light weight and durable sealing for outdoor and industrial applications.

Where is RS-870 used?

Outdoor lighting, electronics enclosures, HVAC panels, and vibration control pads.

How does RS-870 perform in heat and weather?

Maintains flexibility and sealing up to 392 degrees F with excellent UV and ozone resistance.

Is RS-870 available with adhesive backing?

Yes, available with pressure-sensitive adhesives and custom die-cut formats.

What is 2368 Conductive Silicone?

A silver-aluminum filled conductive silicone used for EMI/RFI shielding that meets MIL-DTL-83528 Type B.

In military and aerospace enclosures, radar, communications, and panel-to-chassis grounding.

What are its key properties?

Balanced conductivity, corrosion resistance, and high compression-set resistance with >120 dB shielding.

Can 2368 be die-cut or molded?

Yes. It is available as sheets, extrusions, or molded gaskets.

What is 2571 Conductive Silicone?

A high-durometer silver-copper filled conductive silicone for EMI/RFI shielding, meeting MIL-DTL-83528 Type K.

In rigid aerospace enclosures, structural panels, and defense systems requiring high compression stiffness.

What are its conductive properties?

Volume resistivity of 0.0006 Ω·cm and shielding effectiveness >140 dB across wide frequency ranges.

Can it be molded or extruded?

Yes, available in custom shapes, sheets, and extrusions for MIL-spec sealing applications.

What is 2573 Conductive Fluorosilicone?

A silver-copper filled conductive fluorosilicone designed for EMI/RFI shielding in chemical and fuel-exposed environments.

In aerospace and defense enclosures, connectors, and panels exposed to jet fuels and hydraulic fluids.

BISCO® HT-1240 General Purpose Solid Silicone Pads

SPECIFIC GRAVITY:

1.1 g/cc

DUROMETER, SHORE A [ASTM D2240]:

40 ±5

COMPRESSION SET, 70 HOURS @ 302˚F @ 25% [ASTM D395]:

≤25%

TENSILE STRENGTH [ASTM D412]:

1110 psi

TENSILE ELONGATION [ASTM D412]:

≥240%

HARDNESS CHANGE AFTER HEAT AGING 70 HOURS @ 437˚F [ASTM D573]:

±10

TENSILE STRENGTH CHANGE AFTER HEAT AGING 70 HOURS @ 437˚F [ASTM D573]:

-20%

ELONGATION CHANGE AFTER HEAT AGING 70 HOURS @ 437˚F [ASTM D573]:

-40%

CHANGE IN VOLUME [ASTM D471]:

+10%

CHANGE IN HARDNESS (SHORE A) AFTER OIL IMMERSION 70 HOURS @ 302˚F [ASTM D471]:

-10 to +5 pts

TENSILE STRENGTH CHANGE AFTER OIL IMMERSION 70 HOURS @ 302˚F [ASTM D471]:

-10%

ELONGATION CHANGE AFTER OIL IMMERSION 70 HOURS @ 302˚F [ASTM D471]:

-15%

VOLUME CHANGE AFTER OIL IMMERSION 70 HOURS @ 302˚F [ASTM D471]:

+5 %

A-A-59588:

Compliant

AMS 3301-3305:

Compliant

FDA 21 CFR 177.2600:

Compliant

NSF 51 [File MH62230]:

Compliant

Product Overview

BISCO® HT-1240 — Solid Silicone (Shore A 40) — Technical Overview & FAQs

Product Overview

BISCO® HT-1240 is a soft, general-purpose solid silicone rubber engineered for superior flexibility, low compression set, and outstanding environmental durability.
It offers excellent sealing performance at low clamp loads and maintains elasticity after long-term exposure to heat, UV, ozone, and weathering. This 40-durometer grade is ideal for applications requiring gentle compression and reliable performance in demanding conditions.

Applications

Soft environmental gaskets and door/panel seals
Outdoor lighting and HVAC system sealing
Medical and instrumentation gaskets where low compression force is required
Cushioning and vibration-isolation pads for industrial assemblies

Key Properties

Specific Gravity: 1.10 g/cc
Hardness: 40 ± 5 Shore A
Compression Set (70 hrs @ 302 °F, 25 %): ≤ 25 %
Tensile Strength: 1050 psi
Elongation: ≥ 700 %
Heat Aging (70 hrs @ 437 °F): Hardness ± 10 pts; Tensile – 20 %; Elongation – 40 %
Oil Immersion (70 hrs @ 302 °F): Volume + 5 %; Tensile – 10 %; Elongation – 15 %
Operating Temperature Range: – 80 °F to 450 °F continuous
Compliances: A-A-59588 Class 2A, AMS 3301–3305, FDA 21 CFR 177.2600, NSF 51

FAQs

What is BISCO HT-1240 used for?
HT-1240 is ideal for low-clamp-load sealing applications such as lighting, electronics, and environmental gaskets where soft compression and long-term elasticity are essential.

How soft is HT-1240 compared to other grades?
It’s the softest in the HT-1200 series (40 Shore A), offering excellent conformability and sealing on delicate or uneven surfaces.

Can HT-1240 handle high temperatures?
Yes — it operates continuously to 450 °F (232 °C) and retains its mechanical integrity after heat aging.

Is HT-1240 safe for food or medical applications?
Yes — it meets FDA 21 CFR 177.2600 and NSF 51 requirements for non-toxic, clean-room use.

Can HT-1240 be ordered with adhesive backing?
Yes — it can be laminated with silicone or acrylic PSA for peel-and-stick installation.

Request samples or custom HT-1240 gasket fabrication from H-O Products — your specialist in precision silicone converting and material engineering - contact us.