ESL Diaphragm coating

[arend-jan]

I'm posting this on behalf of harry_at, a member of diyAudio.com but he's unable to post right now (because of a login problem).

For the record, I had similar experience with the Shackman (Reromanus) coating.


Hi folks,

I'm a longtime Quad Esl-63 enthusiast and owner.

Last year (June) I have ordered VLC07 and VLC09 from reromanus to do some experiments. After some days VLC07 (Art.Nr.:45701) was delivered and should give a surface resistance of 10^7 Ohm



In the first hours and days the sound was very promising, but then the sensitivity of the Quad got lower and lower. After opening the panel, I saw that the coating has lost its "grip". You can see (attached picture) that the coating is concentrated only in small areas. Nothing in between. The surface resistance was way to high. It was humid at that time, but a coating which is not adhering to the film and/or is not wetting the film, is not the
best thing for Esl speakers. And it didn't have the desired and promised resistivity for the Esl-63.



Of course I told that Mr. Römer and he replied that the coating was produced with a wrong formulation. They will make a new one. No problem I thought, lets wait a week or two and then I will get a new bottle. No way! Some weeks later he didn't answer my emails. No money back, no new coating.

But the story does not end here. Eight months!!! later I got a new formulated VLC07 bottle (picture attached). Life can be so wonderful! But the surface resistance of this coating is 10^11 and not 10^7 and it smells like a washing detergent...and it doesn't stick to the film...and it doesn't really dry...



And if you are wondering what happened with the VLC09 order? Yes, I'm still waiting and waiting and waiting...

So here's my deal folks: I still have the old and the new VLC07 coating. Drop me a mail which one you will have and I will send it for free worldwide. The "best" things in life are free...Take your choice and try yourself.

Best regards,

Harry



You can reach Harry by sending a message with the diyAudio contact page, his moniker is harry_at.

[SY]

Arend-Jan, thanks for the follow-up. This is a classic example of the effects of no surface pretreatment.

Calvin, a Tesla coil can be relatively easily constructed. That's all a corona treater is anyway.

[MJ Dijkstra]

This is a classical example indeed.



Please note the measuring glass '' package''' Reiner Romer uses
This expensive high quality type of glass is used for quantitative analysis.
The thin line at the upper part of the glass is used to adjust the volume very precisely at 10,00 ml. If the hollow meniscus of the fluid level (the lowest level) 'touches' the thin line you have 10,00 ml. Of course there are larger values than 10 ml, all calibrated.

[JonasKarud]

I thank You, arend-jan, for showing the Shackman (Reromanus) coating.

Glad I didn't order it, but wanted a sample instead!

Now I do not want a sample.

[SY]

This expensive high quality type of glass is used for quantitative analysis.

$3.50 at our local supply house in onesy-twosey.

[MJ Dijkstra]

Originally posted by SY


$3.50 at our local supply house in onesy-twosey.

Yep, but I compare it to a conventional and more appropriate HDPE package which is cheaper, lighter and can't break into peaces.
There could be reason of course to do it this way, I don't know.

[SY]

It looks cool. Gotta justify the price.

[MJ Dijkstra]

Originally posted by SY
It looks cool. Gotta justify the price.

Hi,

59 euro - $3,5= 55 euro

Not anymore, thanks to SY!

[SY]

Got the exchange backward (I'm not happy about the weak dollar). $3.50 = 2E50. Though we don't pay VAT, so maybe it evens out.

[MJ Dijkstra]

Originally posted by JonasKarud

With professisional help from a chemical lab, I developed a coating 15 years ago myself and sent 20 ml samples for free all over the world.


I had to stop when one of the ingredients needed wasn't manufactured anymore.

Hello Jonas Karud,

A second attempt,
are we talking about the bright pink coloured coating called 'Karud coating' distributed until recently by the company Audio4 in the Netherlands??????