L3890 Black Rubber Speaker Adhesive Cement

 L3890 Black Rubber Speaker Adhesive Cement

The L3890 Black Rubber Speaker Adhesive is a high-viscosity (3,500–4,500 cps), rubber-based cement formulated for the loudspeaker industry. In addition, it bonds rubber surrounds, dust caps, gaskets, and lead wires to polypropylene, styrene, butyl rubber, and other difficult substrates, and stays flexible, waterproof, and vibration resistant after curing.

Additionally, L3890 is available in sizes from 0.5 oz up to 32 oz, making it suitable for both quick single-speaker repairs and high-volume recone shops.

L3890 Uses

The L3890 works for demanding speaker repair and assembly jobs, including:

• Bonding rubber surrounds to baskets
• Attaching surrounds on high-wattage, high-excursion subwoofers
• Bonding polypropylene, styrene, and butyl rubber surfaces
• Attaching dust caps to polypropylene and composite cones
• Surround lip to frame on subwoofers
• Lead-wire dressing
• Securing gaskets to baskets

Cure Time and Bond Strength

Once applied, L3890 Black Rubber Adhesive tacks up in about 4 minutes, giving you a short window for adjustments. Fixture cure is about 10 minutes. After that, allow 24 hours for full cure. Depending on materials and ambient temperature, maximum bond strength may take 48–72 hours.

Performance Highlights

• Solvent-based rubber-resin cement built for high-performance and industrial loudspeaker work
• Viscosity: 3,500–4,500 cps (high)
• Softening point: 230°F
• Maximum temperature resistance: 250°F
• Bonds difficult substrates including polypropylene, styrene, butyl rubber, and coated cloth
• Remains flexible across a wide temperature range
• Waterproof bond
• Shock and vibration resistant

Storage and Handling

When stored at 60–80°F, shelf life is at least 6 months. However, lower temperatures can temporarily increase viscosity, while higher temperatures may permanently affect it.

Because L3890 Black Rubber Adhesive is solvent-based, the solvent will evaporate if the container isn’t sealed tightly. Therefore, if it thickens after long storage, thin it with a small amount of toluene.

Important Rebuild Note

L3890 Black Rubber Adhesive is not suitable for bonding spider to voice coil or spider to frame — instead, use CA glue or one of our epoxy adhesives (FLXEP860 or BEP870) for these joints.

Safety Warnings

⚠️ Extremely flammable. Therefore, do not use or store near heat, sparks, or open flame. Also, always use in a well-ventilated area.

⚠️ California Prop 65: This product can expose you to chemicals including toluene, which is known to the State of California to cause birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.