ESL Diaphragm coating

This thread has been going for 17 F-ing years! Unbelieveable!

I used a combo of scraping and GoofOff to get the glue off the grids before replacing the diaphragms. I glued the new diaphragms using 4693H contact cement. Unlike the factory glue, 4693H actually bonds to the film and the grid.

I just rebuilt a pair of Quad ESL-63s. I checked resonance of the drivers before and after spraying with Licron Crystal. Resonance dropped about 1 Hz. Resistivity was 10^8-10^9 Ohms/square. I have drivers that I sprayed with Licron (before "crystal") back in the early to mid 90s (IRIC) and they still read 10^8 Ohms/square (and the 4693H glue is still holding). The stuff works, lasts, and takes only seconds to apply, it's pretty cheap, and widely available. I don't see much point in using anything else.

Here's how I masked the drivers for spraying- 3D printed masks fit over the ends of the drivers and cover the center holes. Note the blue masking tape covering the long sides of the driver. I make four quick, right to left passes over the driver with the Licron Crystal. I sprayed all eight drivers in about 10 minutes. This is, by far, the easiest part of restoring these speakers to as-new operation.

ESL-63 driver with spray masks.jpg



Here's the resonance before and after spraying with Licron Crystal - this one is typical.

ESL-63 driver 31043 resonance BL.jpg


ESL-63 driver 31043 resonance WL.jpg



ESL-63 driver 31043 resistivity.jpg
 
This thread has been going for 17 F-ing years! Unbelieveable!
The stuff works, lasts, and takes only seconds to apply, it's pretty cheap, and widely available. I don't see much point in using anything else.

Well it also depends on your specific application. Your ESLs are pretty well protected against UV for example. A naked audiostatic is not. Some people have their own opinion about the best resistance, added weight etc, each his own up of tea