Sound Varnish, a lacquer for coating loudspeaker driver cones and diaphragms.

Directions for use. Please read carefully.

Working with "Sound Varnish": how to apply the lacquer, which type of brush should be used?

It is best to use a soft brush (that shouldn’t lose its hair)

The entire diaphragm / cone should now be coated with "Sound Varnish", however, excluding the surround of cone speakers and the star-shaped dampers of Manger sound transducers. After applying the varnish to synthetic diaphragms / cones a glossy surface should develop. Depending on weather conditions and ambient temperature the varnish should be left to air-dry for 48 hours. The drying process should not be accelerated by using a hairdryer or by applying any other type of heat.

The completely dried layer of varnish shouldn’t be sticky anymore ("fingernail test"). An entirely dried-up coat contributes significantly to the desired, positive result. Therefore, a little patience is advisable. A second layer should be applied now, and in case the first two layers were quite thin, a third coat is essential. Important is to let the varnish dry adequately, keeping in mind that the more layers of varnish have been applied the longer the dying process will take. Several thin layers should be given preference to just one thick coat.

Dome tweeters and similar driver types should receive only two layers, carefully applied with a small, soft brush. The purpose of coating is not to add unnecessary weight to the diaphragm.

Sound Varnish-D

This is a special version for metal diaphragms / cones and those made of hard synthetic materials (like e.g. fibre glass or Kevlar, but not carbon). Since this varnish possesses a deliberately higher damping, it’s not suitable for bending wave transducers (Manger sound transducer)! Otherwise, the directions for use are the same.

Why is it that important to give "Sound Varnish" enough time to dry completely?

"Sound Varnish" is made of natural resin and belongs to the group of oil based lacquers, meaning that it polymerises when the solvent evaporates. Therefore, a second coat should only be applied on a completely dried first coat. If the first coat is not entirely dry, it crumbles and is lifted of the surface – equivalent to total destruction.

Spirit based lacquers, for example, behave differently: a second coat applied on a not completely dried first coat would lead to partly dissolving the first layer. Afterwards both, combined layers would dry (just leaving unpleasant streaks).

The brush used may be cleaned using commercially available thinners (e.g. turpentine or turpentine substitute. These thinners should, however, not be used for thinning the varnish.

Safety precautions

Last but not least: the varnish should only be used for its intended purpose! Skin contact should be avoided. After accidental contact with "Sound Varnish" the skin should be first cleansed with spirit (unless a person is allergic to spirit) and then with soap and afterwards rinsed with a lot of water. Varnishing should only be done in ventilated rooms; vapours should not be inhaled. The varnish is highly inflammable – keep away from open fire and glowing objects. "Sound Varnish" has been tested successfully on a variety of surfaces – every new manufactured batch is tested again. Nevertheless, the use of the varnish is at one's own risk. Neither the manufacturer, nor the distributor is liable for objects that have been treated with "Sound Varnish". It is recommended to apply the varnish first to a small sample, since the priming coat might be dissolved and destroyed. "Sound Varnish" should not be applied to polystyrene (Styropor®) and other synthetic, foam-based materials.

For further questions please contact: Ultee Audiotechnik, 48607 Ochtrup, Germany. E-mail:

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