ER Audio Conductive Coating

[Ali Tait]

Hi Folks,
I have a pair of built ER Audio Acorns bought from a friend.All the bits and pieces to repair a panel were included,and I recently had to carry out a repair to one of the panels.This worked,but output was very low,so does anyone here know,does the coating they supply have a limited shelf-life?

Thanks.

[geraldfryjr]

Appaarently it does.

Charlie and Mavric seemed to be having the same problem.
I,m not sure but I think it is the same coating. jer

[CharlieM]

Originally Posted by Ali Tait

Hi Folks,
I have a pair of built ER Audio Acorns bought from a friend.All the bits and pieces to repair a panel were included,and I recently had to carry out a repair to one of the panels.This worked,but output was very low,so does anyone here know,does the coating they supply have a limited shelf-life?

Thanks.

Yes, Mavric and I used an unopened bottle of a coating I bought from Just Real Music two years ago, which looks exactly like the ER coating. Anyway, we got almost no sound output from the panel until I recoated the diaphragm with hand soap and then it rocked the house. So, yes, we now know that that coating does deteriorate in a sealed bottle over time.

[MJ Dijkstra]

In fairness to ER one should perform some measurements of the electrical condictivity before stating that the coating has deterioated.
When repairing esls plenty of things can go wrong, the coating just being one of the many possible failures. As the whole process isn't reproducible anyway one should be careful when comparing differnet products.
As the question of the topic starter is directly related to the product of ER one should ask ER first (assuming you didn't). I know ER has some specific recommendations about the shelf-life even if it is not clearly printed on the bottle.

Just my opinion

[CharlieM]

You've made a good point. *I did not mean to imply anything about the
coating from ER Audio. *To be clear, the coating referred to in my post was
not purchased from ER Audio, although it does have a similar cloudy
appearance. **In my case, I used a coating solution that was at least two
years old and I got almost no sound output from the two panels I used it
on. **Since all else checked out and both panels later played loud and
clear after recoating the diaphragms with a different coating, I am
confident that the coating was the problem. *Accordingly, I only posted to
warn others that other coating solutions may likewise have a limited shelf
life beyond which they may no longer work.

[MJ Dijkstra]

Hi Charlie et al,

The succesfull recoating of panels with a different coating still is no absolute proof that the former coating failed. Maybe the second coating had a better contact with the HV-supply to name just a possible cause. The keypoint is that you can only know for sure ,after doing some measurements of the coating itself.
The cloudy appearence is not specific for ER coating

[CharlieM]

Originally Posted by MJ Dijkstra

Hi Charlie et al,

The succesfull recoating of panels with a different coating still is no absolute proof that the former coating failed. Maybe the second coating had a better contact with the HV-supply to name just a possible cause. The keypoint is that you can only know for sure ,after doing some measurements of the coating itself.
The cloudy appearence is not specific for ER coating

Thanks for your reply. I agree that there can be no absolute certainty without measuring the resistance. I will say that I verified power to the stators and the output from the HV supply. My money says the contact to the HV supply was also good but the coating wasn't conducting. Here's why I think so:

http://www.diyaudio.com/forums/attac...s-p4040318.jpg

Rather than a single-point of contact between the diaphragm and HV supply, the diaphragms on both panels contact a copper foil periphery charging ring on all sides, so I think the likelihood of both panels having no contact to their HV supplies is virtually nil.

In any case, I think my bad experience in this case should make everyone wary of aged coating solutions, especially if their makeup isn't known.

[mavric]

Charlie, are we using Licron on both panels? Been a long day and forgot what we spoke about on "that" over the phone. I am ready to rock the house soon. *from my experience so far, this was a costly unfortunate thing, so take into consideration that we spent hours trying do diagnose the problem. *there were no corners cut on material or craftsman ship, i am just happy that the problem was identified and will be fixed and tested, looking forward to this, even though there was a bump in the road. i am all smiles.

[CharlieM]

Originally Posted by mavric

Charlie, are we using Licron on both panels?

Affirmative good buddy... both panels will get new diaphragms and the Licron Crystal coating.

[mavric]

you just made my year! i am sorry posting this on some one elses thread, but there is relevance on this subject. My wife will be happy tonight.
so we are still .0006 film and licron coating, correct? this is so effecient and i will have a hard time sleeping. thanks man. cant wait.