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Bazukaz 10th January 2006 12:57 AM

Diaphragm coating
Hello ,
I would like to ask if somebody knows a good diaphragm coating method ?

Graphite coatings are not uniform , fishing line nylon does not adhere well to mylar, liquid soap seems being not reliable...

I Have searched for hours in the internet , without a success.

Thanks in advance ,

I_Forgot 10th January 2006 01:38 AM

I have had some good results with Licron, a spray-on "permanent" antistatic coating made by Tech Spray. I have not had it on my speakers for long, but others have had it on for years and it is still working.

It is very easy to apply. Just tension and mount the diaphragm, mask off areas as required, and spray on the Licron.

A 10 oz can costs about $40 and holds enough of the spray to make a LOT of ESLs.


Calvin 13th January 2006 11:13 AM


I tested Licron. Itīs easy to apply by spraying action and it gives a good efficiency and quick charge loading. On the other hand, I couldnīt get uniform results, because spraying with such a can, will not give constant results. After drying some segments of my panels looked translucent, while others had the appearance of a salty crust. :-((


I_Forgot 13th January 2006 08:45 PM

It will work just fine anyway.


moray james 14th January 2006 07:20 AM

Something that I will post to stimulate experimentation. Weldbond white glue which is a modified PVA adhesive is made by Frank T. Ross & Sons Ltd. in Toronto. ( when diluted one part glue to five parts water can be sprayed or brushed onto mylar and dries to a fine cloudy thin film. This bonds extreemly well to mylar. You can experiment with quaternium ammonium salts to dope the adhesive to achieve the desired resistivity. The most simple source would be to take a non sented Downy dryer sheet and soak it in some water. Then use the water to dope the adhesive. Many anti static products like hair conditioner or shampoo with added hair conditioner contain such salts and could also be experimented with. Easy to play with and almost free. Weldbond can be found at most any craft store as it is considered a universal adhesive. By the way Weldbond is totally non toxic. Best regards Moray James.

MJ Dijkstra 14th January 2006 04:07 PM

Due to migration effects, the effect of these charged additives may be temporarily. They also depend on the humidty of air to conduct.
Resistance is very dificult to control.
It should also be noted that not all chemical compounds are compatible so you have to know what you are doing.

moray james 15th January 2006 01:41 AM

Finding out
MJ: yes you are completly correct. The best way that I know of to learn what you are doing is to do. With these materials so inexpensive, easy to use and so readily available is to experiment. I would rather spend some of my time playing with mixtures than rubbing graphite which is exactly what the majority of the diy builders use.
Yes there are coatings available (not sure of the cost of the one you use) Licron has now got a good track record but it is expensive. This combination of materials is almost free in comparrison and is totally non toxic. I would be interested in feedback from those who have the interest to experiment with the Weldbond and Quats. I should think that the small amount of mass that the PVA layer will add should also provide some welcome damping to a mylar substrate. I think that it is great to have some diy alternatives to graphite which has for decades been a real bug bear for many (potential) diy builders. I guess time and some trial diaphragms will tell the whole story. Remember that the full cure for Weldbond is about 30 days though in such a fine layer I should think that 20 days (or less) is probably to be expected. If the coating is stable after a month then we can see what kind of long term stability it will offer. Very best regards Moray James.

MJ Dijkstra 15th January 2006 09:37 AM

The effect of damping is very small unless you cover both sides of the membrane and/or are applying a very very thick layer. Both options being awkward and thick layers will cause some other unexpected problems. Usually a single layer adds little weight. For example, my EC-coating adds around 12 mg/100cm2. It is unlikely that such amounts will alter the properties of the Mylar in a siginificant degree. Damping the membrane with silicone dots or with an air-resistance like speaker grill cloth is far more effective. (I personally favor silicone dots)
If you want an alternative for graphite you may try my EC-coating.
Its mechanism of conduction is similar to graphite (electronic conduction) and it doesn't take a month to cure.

Capaciti 15th January 2006 12:48 PM

Hi folks,

i use the EC-coating from Martin Jan and i am wondering why others mass around with graphite or other time consuming methods.

The EC-coating isn't expensive and it works, is very easy to apply and, at least thats what Martin mentions, will have a life cycle of many years.

The only question, which i still asking myself is, why ML or audiostatic quit using EC-coating ??


MJ Dijkstra 15th January 2006 07:27 PM


Neither ML or audiostatic used my EC-coating.

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