Hi Few,
I haven't tried the original Licron but I've read posts that described it as being quite thick. The Licron Crystal coating is not very thick. I put a micrometer on a test coat and (not a micron scale instrument) and I estimate it to be about 1.5 microns thick when sprayed "just wet"-- that is; just wet enough that the aerosol droplets merge together into a continuous wet film. The wet film looks very thick but 95% volatiles. It takes a good 30-40 minutes to flash off dry and several hours before you'd want to handle it. When I sprayed it on there were some fingerprints on the diaphragm that didn't want to wet over so I used a small foam brush to smooth it over and it did then cover over the fingerprints. Since I now know that you can smooth it out wet with foam brush, I suspect you could obtain a much thinner coating using a foam brush-- perhaps spray some on the brush first to wet it, then spray a mist coat on the diaphragm and then "wet it over" with the brush. It may have even higher resistance if it's thinner and and that would be a good thing too, since the advertised resistance as sprayed is a bit lower than optimum @ E7-E9 ohms. The downside is an 8 oz can will cost you about $50 with shipping. BTW, how's that wire stator coming along?
The newer Licron Crystal 1756 is vast improvement over the original. It is much more durable, has higher resistance, goes on thinner, and is optically clear(if that is important to you). I have been using an air-brush to apply a single thin layer rather than using the spray can nozzle. The results are very uniform durable 2E-9 ohm/sq. coating.
http://www.diyaudio.com/forums/planars-exotics/109789-esl-diaphragm-coating-20.html#post1942380
Yes,It seems that others as well I has had much much better results with the new licron formula.
So I will be sticking with it for the time being.
Someday after I get everything else done and some decent measuring devices I will do some more experimenting with different types coatings as I enjoy R&D.
Steve,have you tried any dilution methods to see if you can bump up the resistance a point or two?
I have found that on my panels they still play even after I try to discharge them.
Only after they have been sitting around for a few days is when I barely here any sound out of them compared to when I first fire them up.
With the old formula I can discharge them and there done playing. jer
So I will be sticking with it for the time being.
Someday after I get everything else done and some decent measuring devices I will do some more experimenting with different types coatings as I enjoy R&D.
Steve,have you tried any dilution methods to see if you can bump up the resistance a point or two?
I have found that on my panels they still play even after I try to discharge them.
Only after they have been sitting around for a few days is when I barely here any sound out of them compared to when I first fire them up.
With the old formula I can discharge them and there done playing. jer
Ger: if you dilute you will raise the resistance of the coating which will make it harder for charge to discharge off of the diaphragm. If you want the diaphragm to discharge faster you will need to decrease the resistance of the coating. About one Gig ohm is an excellent resistance to prevent charge from migrating during play on low notes.
"Ger: if you dilute you will raise the resistance of the coating which will make it harder for charge to discharge off of the diaphragm. If you want the diaphragm to discharge faster you will need to decrease the resistance of the coating. About one Gig ohm is an excellent resistance to prevent charge from migrating during play on low notes.
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moray james "
I was just wondering if any one has tried this with any of the licron formulas because I don't have a air-brush setup yet. jer
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moray james "
I was just wondering if any one has tried this with any of the licron formulas because I don't have a air-brush setup yet. jer
No, I hadn't tried diluting Lycron Crystal.
A surface resistance of 1e-9 ohm/sq seems to be a good compromise between reducing charge migration and distortion while keeping charge time and humidity effects low.
Charging and discharging a panel that uses Licron Crystal shouldn't take more than 15 -20 seconds or so.
If you are having issues with long charge or discharge times it could be:
1) You are experiencing poor connection between the coating and the HV contact.
2) You have some areas of your diaphragm that are not uniformly coated and don't have good charge/discharge paths to the HV contact; think islands of charge on the diaphragm with no place to go.
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For painting the stators do you just paint the outside parts that are exposed to the world and leave the inside bare?
I currently have Maggies, but only got them because I could never afford Martin-Logans or the likes (even back when $2K actually got you real ESL, the Aeries). And now I'm getting interested in building some ESL's. But we just welcomed our first baby to the family so I have to think about "murphy's law" here.
I currently have Maggies, but only got them because I could never afford Martin-Logans or the likes (even back when $2K actually got you real ESL, the Aeries). And now I'm getting interested in building some ESL's. But we just welcomed our first baby to the family so I have to think about "murphy's law" here.
The stators have 12 mils of polyurethane on both side and it's important to also get a good coating on the panel edges. Generally, a paint gun is to be held perpendicular to the surface being sprayed but for stators, angle the gun slightly, let's say +45 degrees on one coat, then -45 degrees on the next coat--this to insure the paint coats the hole edges-- also apply first coats with a mist and allow tack time between coats-- if you spray real wet the paint will run away from edges. I used a vernier caliper to check the paint thickness but you could also use a micrometer or even use something of known thickenss for visual comparison. I measured before spraying and during also-- when the panels measured +.024", I knew I had 12 mils (.012) on each face. The automotive paint was about $60.
pics
Charlie, if you want, i will post pics of you spraying my panels.
your back ground with auto body work is simply awesome, and some may not understand without seeing with their own eyes.
I like the word "ouch" ,
still trying to find an EQ to atennuate certain frequencies, still have alot of pics with the RTA,
I hope you have a something to get you going again, this is addicting. later
Charlie, if you want, i will post pics of you spraying my panels.
your back ground with auto body work is simply awesome, and some may not understand without seeing with their own eyes.
I like the word "ouch" ,
still trying to find an EQ to atennuate certain frequencies, still have alot of pics with the RTA,
I hope you have a something to get you going again, this is addicting. later
Charlie, lets us be clear.
you inspired me on the panels, the best sound i have ever heard.
I was reading from your first post, on this toppic.
Tell you this, still amayzed, nothing sounds like this AND i am still trying to find something even close, thats where the RTA came in, nothing has this sound, or even close.
thanks man, you Jazzman.
you inspired me on the panels, the best sound i have ever heard.
I was reading from your first post, on this toppic.
Tell you this, still amayzed, nothing sounds like this AND i am still trying to find something even close, thats where the RTA came in, nothing has this sound, or even close.
thanks man, you Jazzman.
Well, this is a bit different than what you described in your original question in post#25.
But, it may be a result of the same problem of a poor diaphragm contact.
It is not unusual for an ESL diaphragm to acquire a slight charge when it is unplugged for some length of time. So, even without a bias charge hooked up you will get some sound out of the panel. If the acquired charge is negative and your bias charge is positive, when you hook up the bias voltage the panel will momentarily get quieter before getting louder as the diaphgram charge goes from negative to zero and then positive.
I think what you are saying is that you have to increase the bias voltage above a certain voltage level before the panel starts charging. One possible reason for this is a poor HV contact on the diaphragm. You can investigate this using a charge indicator. If you don't see any indication of charging taking place until your bias voltage reaches a certain level and then charging starts, you probably have a problem with your HV contact.
See the following post for more details.
http://www.diyaudio.com/forums/planars-exotics/153773-esl-technical-questions.html#post1958015
After painting, the mating stators are assembled using 3-M double-sided foam mounting tape (3/4" wide x 1/16" thick). The tape is applied to the periphery edges of both stators. On one stator the tape holds the diaphragm in place. On the mating stator, a 1/4" wide copper charge ring is applied, then the stator halves are mated together. The foam mounting tape is what holds the two stators together. On the speaker itself, the wooded frame is rabbitted (relief-cut) to accept the thickness of the panels and wooded strips hold the panels into the rabbits with screws. No screws go through the panels, though.
I could post a sketch of the wooded frame if that would help. Also see my blogpage to see how the panels are assembled with the foam mounting tape.
If you check out Mavric's threads, his panels are assembled the same way and there are photos that may help clarify. The great thing about the 3-M double sided mounting tape is that it serves as both the spacer between diaphragm and stators and it's the adhesive that holds everything together-- it's very easy and fast and no mess. The downside is that the ozone in the air may deteriorate the foam after a few years and the panels would then need to be rebuilt (new tape and diaphragms replaced).
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