Does Silver Conductive Paint work for panel diaphragm?

[FPN]

Hi Guys,

I have Aerius with dead panel due to age and have several plan like purchase new panel or purchase the repair kit.
Before I do my plan, I think no harm for me try to repair by myself and did some experiment with my dead panel.
I did read a lot of article in this forum and from others how to coat the diaphragm.
I can't find transparent conductive liquid in my country buy I did found someone sell the Silver Conductive Paint from Electrolube and from Leitsilbher (L100) with grey color (not transparent)
They sell very cheap $25 for Electrolube and $19 for L100.
I'm wondering if any of you have the experience doing re-coating use silver conductive paint.
Does it work well with ML diaphragm?
Thanks in advance for all of your information.
Cheers.

 

[roberto]

Hola FPN. Well, I haven´t used the silver paint on the panels, but yes at the printed circuit boards. I think that you might found a good conductor for the red cable that must be touching the diaphragm. Martin Logan use bare wire (red) with about one inch peeled and with the aid of a adhesive tape, holds this wire against the diaphragm. Please tell us your findings. I do not know any reason why not to use the silver paint for this matter. Secure the wire with this kind of tape too. There is noting to loose and many things to win. Again, tell us your findings. Happy listening!

 

[FPN]

Hi Roberto,

Nice to hear from you!
I'll try in the near time and update the result in the forum.
Maybe the apprearance will be ugly (not transparent) and the color may not match with the stator and frame, but who care if it's work.
Thanks mate.

 

[roberto]

Where the cable is located, is a hidden part and you are not able to see it. It is located at the bottom of the stat panel, and usually is placed at the lower center. With much care, perhaps with this silver liquid you could make a better contact. Just hope that the silver coating with not react with the oxygen. Remember to place the adhesive tape back again. Happy listening.

 

[greg2putt]

Just a request for the curious, perhaps you could video your process and reassembly with red tape, etc. so that we could all learn from your experience no matter the outcome.
Thanks

Greg

 

[FPN]

Thanks for the advice Roberto, I'll try to re-coat the cable connection.
I do hope the silver paint didn't corroded and long lasting as I'll dilute them into solvent to make it spreadable and create very thin film so it doesn't add too much weight on the diaphragm.
By the way, I did saw picture of someone in this forum who repair his panel put new copper trip to the other side of the diaphragm then make line to the existing line through the bottom of the panel.
Do you know why he just cover the bottom line copper strip use double tape, where he didn't cover the other side?
Thanks.

Where the cable is located, is a hidden part and you are not able to see it. It is located at the bottom of the stat panel, and usually is placed at the lower center. With much care, perhaps with this silver liquid you could make a better contact. Just hope that the silver coating with not react with the oxygen. Remember to place the adhesive tape back again. Happy listening.

 

[FPN]

Just a request for the curious, perhaps you could video your process and reassembly with red tape, etc. so that we could all learn from your experience no matter the outcome.
Thanks

Greg

Hi Greg,
Maybe not with video as this may too difficult to take video while I'm working with the panel.
But let me try and for sure I'll take many picture for and give comment on the detail/difficulty/problem so everyone will learn from my experience.
I'll start my project this weekend once I back from business trip.
Wish me luck mate..
Thanks.

 

[MPS]

Generally high resistance coating is considered preferable but that doesn't mean that (high conductive?) silver paint doesn't work. I would also be somewhat concerned about the durability of the paint, is it elastic enough not to chip off..

 

[FPN]

Generally high resistance coating is considered preferable but that doesn't mean that (high conductive?) silver paint doesn't work. I would also be somewhat concerned about the durability of the paint, is it elastic enough not to chip off..

Hi MPS,
To be frankly, I'm also not sure.
The idea is make very thin silver paint solution in solvent so they are spread able and hope the paint bonding agent still work as adhesive.
I might not coat the diaphragm too thick as the objective to pit the silver paint on the mylar and hope doesn't chip off.

 

[roberto]

Hola. Where this red one inch bare wire (red) goes, there is no movement at all...just the DC bias for the whole panel. The connection of this wire to the diaphragm is made only by contact and the tape secures the wire against the diaphragm. This had being done since. You can relocate the wire moving it up to two or three inches to the left or the right of the diaphragm. The silver paint will make a better connection. I am going to ask to the service department if this will be a way to do it. Stay tuned for their response. Happy listening!

 

[Tosh]

Generally high resistance coating is considered preferable but that doesn't mean that (high conductive?) silver paint doesn't work. I would also be somewhat concerned about the durability of the paint, is it elastic enough not to chip off..

It won't work because the paint will be too heavy, too conductive, and will either not stick to the diaphragm, or worse, might react with (dissolve) it.
You need a proper resistive coating solution (IF that is even the reason the panels are not working....?) Look on DIYAudio.com for options about ESL diaphragm coatings.

 

[Tosh]

On second thought I think the conductive paint will stick without harming the mylar, so it could be used to repair the connection to the wire. But don't expect paint to work for re-conditioning the resistive coating, as it is too heavy, which leads to weak highs and poor efficiency.
What exactly are the symptoms of the "dead panel due to age"? I understand that in an aging panel the highs kind of fade away.

 

[FPN]

Hola. Where this red one inch bare wire (red) goes, there is no movement at all...just the DC bias for the whole panel. The connection of this wire to the diaphragm is made only by contact and the tape secures the wire against the diaphragm. This had being done since. You can relocate the wire moving it up to two or three inches to the left or the right of the diaphragm. The silver paint will make a better connection. I am going to ask to the service department if this will be a way to do it. Stay tuned for their response. Happy listening!

Hi Roberto,
Thanks for your help!
Very appreciated.

 

[FPN]

On second thought I think the conductive paint will stick without harming the mylar, so it could be used to repair the connection to the wire. But don't expect paint to work for re-conditioning the resistive coating, as it is too heavy, which leads to weak highs and poor efficiency.
What exactly are the symptoms of the "dead panel due to age"? I understand that in an aging panel the highs kind of fade away.

Hi Tosh,
Thanks for your response.
Interesting thought...
My panel not 100% dead, still can hear the sound but very2 weak, I must put my ear very near to the stator to hear the sound.
I did vacuum (didn't work) then shower it (improve with very small margin) with no success.
The only choice now is to repair it or replace with new panel.
I did email Rob from ERAudio in Aussie and he suggest to recoat the diaphragm.
Rob is very helpful man and he actually provide the repair kit for cheap price $90, but going up to $190 if I damage the mylar (need mylar replacement).
If I fail to recoating my panel, I'll order the repair kit from him.
I just want to doing DIY and nothing to lose.
I also call Martin Logan service team, Scott suggest me to replace the panel due to age (my Aerius made in 1992) and their distributor quote me $1,200 incl. shipping.
I can't justify to purchase the replacement panel due to fact that my Aerius is too old and with that cost I can purchase 2nd hand ML in working condition in my place.
With your information, I'll did experiment before apply silver to the diaphragm.
I have choice to use carbon conductive liquid for recoating the mylar.
What do you think, is it will help to reduce the weight?
Thanks.

 

[roberto]

Hola. First of all, the silver paint must be placed exact where the peeled one inch red cable will be touching the diaphragm. No other coating must be use. The diaphragm is an atom level vapor deposited with a special adhesive. There is no way, unless you use the same way, to make this plastic diaphragm to be conductive again. If you use a different material, conductive way to make it to sing again, you might change their sound and efficiency. On the other hand, If you decided to buy, you get two brand new panels, and also you get, from their serial number, the five year Martin Logan warranty. If any problem arise with those panels, the factory will replace them free of charge. On the other hand, yes, it is expensive. Also, you are right. The speakers are 21 years old. It is time to think to replace them or re-panel them. Just my thoughts: I will have again, the sound of my Aerius as new! Will have a warranty with the same as a brand new product for the panels only. Difficult decision. Happy listening.

 

[FPN]

Hola. First of all, the silver paint must be placed exact where the peeled one inch red cable will be touching the diaphragm. No other coating must be use. The diaphragm is an atom level vapor deposited with a special adhesive. There is no way, unless you use the same way, to make this plastic diaphragm to be conductive again. If you use a different material, conductive way to make it to sing again, you might change their sound and efficiency. On the other hand, If you decided to buy, you get two brand new panels, and also you get, from their serial number, the five year Martin Logan warranty. If any problem arise with those panels, the factory will replace them free of charge. On the other hand, yes, it is expensive. Also, you are right. The speakers are 21 years old. It is time to think to replace them or re-panel them. Just my thoughts: I will have again, the sound of my Aerius as new! Will have a warranty with the same as a brand new product for the panels only. Difficult decision. Happy listening.

I see..
Thanks for the input.

 

[FPN]

Hi Roberto,

You are correct, I try to coat the diapraghm with silver paint but it doesn't work.
They are too heavy and not well spreadable and not even. They also tend to flak and I guess it will chip easily.
I'll try to use Calvin recipe from DIYAudio just for testing purpose as I spoil the mylar on top and bottom when try to split the stator..

 

[FPN]

Hi Guys,

Just finish restoring my Aerius.
Both panel work now!
Thanks to all of you for your input and contribution!
It's really pleasure to hear such SOUND!
I did repair my panel only cost me $4!!
Hope long lasting!
Thanks for CALVIN and WACHARA from DIYAUDIO for all the tip and recipe.
And not forget thanks to ROB from ERAUDIO...
I'll post step by step with many of picture so all of you who willing to DIY your panel can try.
Now I'm proud become MLO with functional speaker and I really enjoy the sound!
Thanks everyone!

 

[Leon]

Looking forward to your report. Glad to hear that it worked out and ended well.

 

[FPN]

Hi All,

Below is my report on re-coating my Aerius.
Any question please don't hesitate to ask me.
Re-coating Martin Logan (ML) Aerius Panel

Material to prepare:
• Big plastic spoon
• Cutter
• PVAc glue (white glue/school glue/wood glue)
• Black Ink (Chinese ink/permanent ink)
• Electrical tape (vinyl tape)
• Textile tape (any other non-conductive tape)
• Facial Tissue (toilet paper/towel paper)
• Water distillation (car battery water/tap water)
• Alcohol 70%
• Hammer & towel (rubber hammer)
• Screw driver
• Pipet (tools to drop liquid, usually use to drop children medicine syrup)

1. Open the panel from the frame:
I didn’t explain this step in detail as someone files it (I’ll attach to my post later) with very good step by step explanation and picture. I’ll explain in brief just to refresh. Lay down the speaker with panel facing up, remember to put cushion or something height enough to make gap between the binding post with the floor (I use a small bench) so it will not stressed the binding post. Punch the bottom side rail (one by one) start from left side rail then right side rail use rubber hammer (I use iron hammer but use thick towel as cushion between rail and hammer when I hit the rail. Do until the rail sliding and out from the quick lock.
After the rail gone, pull the panel each side (one by one) to remove the Velcro bonding (yes ML use Velcro to hold the panel to her frame) and put aside. Then loose the screw at terminal block to pull panel wire (black, red and blue cable).

Now you detached the panel from the frame!
2. Split the panel:
Below is the picture of the panel with stator (perforated metal) at front and back of the panel then diaphragm (Mylar) in between stator. To keep Mylar away from the stator ML use double tape as spacer.

ML panel is curve and hence create difficulties when try to split it as the double tape in between Stator and Mylar is very sticky due to age (mine is 21 years old). The double tape only exist at the top and bottom of the panel, the side panel is not attached by double tape as ML use the frame to create tension between the panel sandwich. You need to be really careful when try to split the panel, if possible don’t damage the Mylar (I did!).
Stand the panel in vertical, then use pipet to drop the alcohol in between the stator and Mylar (yes, drop the alcohol to the double tape from end to end). Wait around 2-3 min and let them to run down and soften the tape.
Use the cutter to cut the double tape, cut as near as the front stator (so you not damage the Mylar) to create gap (Mylar stick on the back stator) so the big plastic spoon can push into the gap to split the panel. Start from the edge and don’t use force to much, while the spoon inside you slide spoon little by little and always drop the alcohol to soften the double tape (pic. 1 & 2).

Picture 1

Picture 2
If you have difficulty with the soft sticky tape which carry / damage the Mylar use the cutter to cut them and localise the damage. Better to have minimal damage then you lost entire Mylar!
After split the panel you can see that the double tape only exist on top and bottom of the panel and the Mylar stick on back stator (pic. 3).

Picture 3

Do the same technique to split the bottom panel, be careful not to damage the copper strip and the cable when doing bottom panel as the wire is not soldered to the copper strip, just attached use twisting the bare cable at the copper strip. Once you split the panel un-twist the bare wire and loose it from the copper strip for safety (not to spoil the copper strip) see pic.4.


Picture 4
I did made damage on top and bottom of the Mylar for my first attempt for left speaker, lucky ML use section by section diaphragm separation so there is still enough tension at the Mylar at the un-broken section so don’t worry too much if you spoil the top and bottom section (the sound maybe a not as good as the original but still work!) see pic. 5 and 6.

Picture 5

Picture 6
Put the back stator + Mylar in flat place r bench work (I carton box just for easy to find when I work on it).




3. Clean the stator and Mylar:
Here is the picture of the back stator with Mylar attached on it :

Picture 7
You can see the 21 years dirt on the Mylar! Clean uses tissue/paper towel and alcohol. Rub panel use tissue wetting by alcohol section by section, try to change the paper as often as possible to avoid the dirt stick back to the Mylar. Don’t forget to peel the copper strip tape paper (the copper strip use copper tape and there is a protection paper on top of it) and scrap it as you need to clean the copper strip and make new connection on with the Mylar.

Picture 8

Picture 9

After clean, don’t peel the original/existing double tape as you may damage the Mylar just peel the “safe” double tape which contain dirt only, later we cover the old double tape use electrical tape (nylon tape).
Clean Mylar picture:

Picture 10
You also need to clean and peel the excessive double tape on the front stator. Once it clean then you can start working with front stator, cover the top and bottom front stator with electrical tape (1 layer is enough but you can make it 2-3 layer if you wish) to create new spacer (protecting Mylar not to touch front stator). Picture 11

Don’t peel the front layer double tape protection otherwise you will stick the Mylar with front panel later and this is not good when you want to clean or replace Mylar in the future. Here is the finished electrical cover on front stator:

Picture 12



4. Prepare the coating liquid:
Put 80ml of water into plastic can (this can use to coat many panel!) then add 20 gram of PVAc glue then stir until glue dissolve into water and create suspension. Add 1 drop (0.1 ml) black ink into the suspension and stir well until the suspension colour become grey-is. Then coating is ready!

Picture 13
5. Re-coating the Mylar:
I use the sponge and cut the end with 45 degree angle just to make it easy when spread the liquid into the Mylar.

Picture 14
Apply the coating use sponge and squeeze the sponge so the sponge not carry excessive liquid as we only need to apply the coating in very thin layer. I do suggest spreading only 1 times and not twice as maybe too thick but it depend on you how to apply it. Spread section by section, start from 1 end to other end in one goes, just run your sponge in one way. It’s important to coat the copper strip (by section only no need to put coating liquid on to whole copper strip!) and near the end of the Mylar but don’t over spread and touch the stator. Also important not to coat the middle spacer which create the section as it will create spark when you run the speaker. You also need to coat under the end of copper wire which will connect to the red cable.
Make sure you make even coating and not to apply circular or return coating as it may effect on the thickness of the coating and also the transparency of your panel!
Below are the pictures for easy understand what I done:

Picture 15

Picture 16
Let it dry in open air (I’m living in tropical country with 32C and 98% humidity so it will dry in less than 2 minutes) then you will see a grey-is colour on the Mylar, make sure there are even coating.

Picture 17

Picture 18


Picture 19


Picture 20

Picture 21
After dry, attach the red cable to the copper strip. I didn’t use solder to connect wire as I might have to replace the copper strip and the wire in the future so what I did just to secure the connection as tight as possible and later I fixed the connection with electrical tape. I cover all the cover strip from top to bottom and cover the horizontal top and bottom of the Mylar.

Picture 22



Picture 23

Picture 24

6. Assembly the front and back stator:
Assemble back and front stator to its original position. Please take note that both of my panel didn’t align between front and back stator and when I assemble I did back to the original position even it’s not nice. It’s important to put back both segment spacers into its original place as it may effect on the tension (and the sound) of the Mylar as this is tunning by ML. You can use the double tape at the top and bottom of the panel like it’s original if you want (it’s neat and make sure you use 3M VHB double tape as normal foam double tape wouldn’t strong enough to hold the front stator) but I didn’t put double tape as it will difficult to dismantle when I need to clean up the Mylar in the future. I use the textile tape (but not performing well, I’ll replace with the better quality or maybe use other tape or clear packaging tape) to hold the top, bottom and side of the panel. You don’t need to worry with the side panel as it hold tight by the side rail (make sure you have good and thick side double tape and don’t peel the top protection at your frame as the original) and wouldn’t move.
Below id the picture when finish:

Picture 25

Picture 26
7. Assembly the panel to frame:
When you finish, assemble the panel to the frame and try to play the music.

Do for the other speaker as above step then……
ENJOY THE MUSIC!!!


HAPPY LISTENING!!!
Regards,
FPN