Is Licron Crystal good/suggested or not?
Hello Friends,
I finally got a can of Licron Crystal a few weeks ago, but still no time to do the job.
So, before to go, do you confirm Licron Crystal to be among the best coats or not?
The last posts from Legis and Gerald made me some confusion.
Many thanks and kind regards,
Andrea
Hello Friends,
I finally got a can of Licron Crystal a few weeks ago, but still no time to do the job.
So, before to go, do you confirm Licron Crystal to be among the best coats or not?
The last posts from Legis and Gerald made me some confusion.
Many thanks and kind regards,
Andrea
I used Licron Crystal on my current panels that I refurbished about 2 1/2 years ago, using one coat sprayed "just wet". I haven't done any measurements; just relying on my ears, but my speakers still sound great so I figure if there were a significant degradation occurring, I would have noticed it by now.
I should also point out that my panels use a copper foil charge ring around the panel edges, rather than a single point connection to the bias supply.... not sure it matters but I suppose it could.
Didn't mean to sound confusing.
But I swear by it as I haven't had any issues with it so far.
Like Charlie said just make sure that you have a good wet coat when you spray it on as it will cure so thin you won't believe that it is there.
My little panels still worked flawlessly with no degradation after two years of its application.
I talked to our friend Maveric the other day and he says his panels are still kickin A$$ and he was one of the first ones to use Crystal on his very first panels after I had tried it, as it has only been about for about 3 years now.
I think the main issue has been that it is not cheap and some try to use it sparingly and/or try to make it thinner so that it is not as cloudy.
This may be possible but it will take some experimenting to get it any thinner and still have a reliable coating.
Even with a generous coat or two I can't measure the resistance with my 20 Meg ohm DVM or its exact thickness as it is only a few microns.
jer
But I swear by it as I haven't had any issues with it so far.
Like Charlie said just make sure that you have a good wet coat when you spray it on as it will cure so thin you won't believe that it is there.
My little panels still worked flawlessly with no degradation after two years of its application.
I talked to our friend Maveric the other day and he says his panels are still kickin A$$ and he was one of the first ones to use Crystal on his very first panels after I had tried it, as it has only been about for about 3 years now.
I think the main issue has been that it is not cheap and some try to use it sparingly and/or try to make it thinner so that it is not as cloudy.
This may be possible but it will take some experimenting to get it any thinner and still have a reliable coating.
Even with a generous coat or two I can't measure the resistance with my 20 Meg ohm DVM or its exact thickness as it is only a few microns.
jer
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Hello Legis,
When you recoated with ERaudio coating, did you replace or recoat the copper tape charge ring around your panel?
I'm wondering if perhaps you had a problem with the Licron coating being "eaten" away around the edge of the copper tape, rather than the coating as a whole.
http://www.diyaudio.com/forums/planars-exotics/109789-esl-diaphragm-coating-59.html#post3097958
Did you happend to measure or test the coating for conduction before and after the recoat? An easy test is to place two coins down on the coating a few inches apart and apply the HV supply with charge indicator to the coins, ground to one coin and HV output to the other. If the coating is still good you will see flashing on the charge indicator. Rapid flashing = lower resistance, slow flashing = higher resistance.
If the two coin test shows good coating conduction in the middle of the diaphragm, you can test the charge ring be placing one coin an inch or so away from the copper tape at various locations along it's length. With the HV supply connected to the charge ring, connect the coin to ground and look for flashing of the charge indicator. You would like to see rapid flashing at all positions along the copper tape.
Hi,
I did not replace the charge ring nor it's coating, just treated the radiating area of the membrane. I put triple coating over the charge ring back then. I did not measure the surface R that way, but that is a good trick to know in the future, thanks. With other indicators it's quite clear to me that the surface R got lower because of the ER audio coating.
Thanks for the clarification on the recoating and charge ring.
Your experience is very puzzling/concerning as this is the first I have heard of anybody having issues with Licron coating evaporating after a few months of use. I have one pair of panels that have been in daily use for nearly 3 years with no loss of sensitivity or change in charge rate.
Did you notice any difference in the appearance of the coating?
For instance, did you notice a pattern of rings that match up with the perforations in your stators? This might indicate low level ionization from the sharp edges of the stators was attacking the coating.
Your experience is very puzzling/concerning as this is the first I have heard of anybody having issues with Licron coating evaporating after a few months of use. I have one pair of panels that have been in daily use for nearly 3 years with no loss of sensitivity or change in charge rate.
Did you notice any difference in the appearance of the coating?
For instance, did you notice a pattern of rings that match up with the perforations in your stators? This might indicate low level ionization from the sharp edges of the stators was attacking the coating.
After reading this a thought occurred to me:
I've always attached the diaphragm to one stator and the charge ring to the opposing stator and I haven't experienced any problems so far. Although this obviously provides a workable electrical contact, perhaps the contact is not so intimate as to prevent arcing between the charge ring and diaphragm coating. For the charge ring, I use adhesive backed copper foil from McMaster-Carr, which is available with either a conductive or a non-conductive adhesive backing. Now I'm thinking it might be better to use the foil with the conductive adhesive and place the charge ring on the same stator, with its conductive adhesive directly against the diaphragm coating. I'm thinking this would provide a more intimate electrical coupling, less prone to arcing... any thoughts on this?
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I always recommend using the conductive adhesive version of the copper tape stuck down on top of the the coating. It is definitely less prone to corona discharge along the edges of the tape. Try it in the dark with the top stator removed. The non-conductive tape will glow purple long before the conductive tape will.
Calvin's recommendation of a thin layer of paper soaked with conductive coating fluid layed over the copper tape out on to the coating also helps avoid the large resistance discontinuities which leads to corona forming along the tape edges.
BTW, corona discharge along the tape edges becomes more of a problem for HV bias levels above 3kV.
The coating looked untouched, nothing had changed compared to when I applied it (at least to my eyes). It had not even collected any dust that is worth to mention, even though I vacuum cleaned the membrane (through the stators) only once during this time. I used 4,6kV bias the whole time and the stats were completely turned off for every night to avoid dust collection.
Has someone else noted that the feel of presence, attack and dynamics change when the surface resistance of the coating changes, even though the sensitivity does not change much? The net effect to the sensitivity was only 1,5-2dB, and I could still play >100dB(C) with music material (Radioshack meter), but the sound was much gentler, politier and lacked the huge drive that is there when the surface resistance of the coating is lower (meaning normal Licron). Sounded a tad like the sound was not projected from the speaker/membrane, but little behind it, if it does make any sense.
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I'm stumped.
You don't use particularly high bias voltage or stator voltage.
There was no obvious physical change to the coating.
Is it possible that your assembly method could have physically stressed the coating along the spacer boundaries adjacent to the copper tape? I remember you mentioning cranking down on the bolts that hold the front and rear stators together.
Yes I have dampened the stators with nylon bolts, but I don't think they affect the membrane. The front stator is mainly clamped towards the rear stator, so the membrane should not be affected much. Maybe there could be a slight difference but I can hardly believe it has caused this gradual effect.
I have wondered if the reason is the slightly porous (not completely transparent) surface that the sponge application method gives? Maybe this affects somehow, combined with the very thin layer to which the sponge application results.
Measuring the adhesive side of copper foil with non-conductive adhesive I get > 100 Mohm between probes placed one inch apart.
For copper foil manufactured with conductive adhesive, I get about 10 ohm.
I was wondering about possible clamping stresses on the left and right side spacers adjacent to the copper tape. The thought was this might slowly cut off the inner area of the diaphragm coating from the outer coating strips on the spacers that contain the copper tape.
It's certainly possible, but I haven't experienced anything similar to date.
I will keep my eye out for similar behavior with thinner, sponge applied Licron coatings on some of my test panels.
The reason I had previously asked about any changes in appearance was that I did some destructive testing of Licron coating, subjecting it to hours of heavy corona discharge and ozone. Once I started to notice changes in the physical appearance of the coating in the areas of most vigorous corona I could also measure increase in the resistance. These areas appeared to be thinned and slightly more hazy.
Hi,
So finally I have been able to source a full can of Licron crystal, as the current small sample is running out. I have had to carry it to the plane, so spilled the pressurized can to small bottles.
Anybody knows what is the shelf-life of it after having received contact with air(bacterial attack, etc.) ?
Regards,
Lukas.
So finally I have been able to source a full can of Licron crystal, as the current small sample is running out. I have had to carry it to the plane, so spilled the pressurized can to small bottles.
Anybody knows what is the shelf-life of it after having received contact with air(bacterial attack, etc.) ?
Regards,
Lukas.
Told ya! Use water based staff! Check Finland distributor of 6300/6400
Armeka Engineering ESD | Yritys Ask for 4oz bottle.
back to the subj
I believe it would be O'K as long as solvent stays in as in any lacquer/paint. It's alcohol based: go figure.
quote
10. STABILITY AND REACTIVITY
STABILITY: Stable under normal conditions.
POLYMERIZATION: Will not occur.
CONDITIONS TO AVOID: Heat, flames, ignition sources, and incompatables.
HAZARDOUS DECOMPOSITION PRODUCTS: Hazardous decomposition products include oxides of carbon,
silicone, and nitrogen.
INCOMPATIBLE MATERIALS: Oxidizing materials
end quote
Hello Bazukaz,
the next time you wanna buy a can of Licron Crystal, I kindly suggest you to buy it in Europe.
You should contact (as I did) the master distributor ITW Contamination Control: www.itw-cc.com
ITW Contamination Control
Saffierlaan 5
2132 VZ Hoofddorp
The Netherlands
Tel. +31 88 1307 400
Fax. +31 88 1307 499
Email: info@itw-cc.com
They will address you to the nearest /proper reseller.
Regards,
Andrea
the next time you wanna buy a can of Licron Crystal, I kindly suggest you to buy it in Europe.
You should contact (as I did) the master distributor ITW Contamination Control: www.itw-cc.com
ITW Contamination Control
Saffierlaan 5
2132 VZ Hoofddorp
The Netherlands
Tel. +31 88 1307 400
Fax. +31 88 1307 499
Email: info@itw-cc.com
They will address you to the nearest /proper reseller.
Regards,
Andrea
After thinking about your description a while, I think I may have experienced something similar once with an Acoustat panel. It seemed to be totally lacking in low end authority and sounded a little more distant. The panel did have slightly less output than others I had on hand, but not enough to make me think that was all there was too it. After more careful measuring with mic positioned close to diaphragm, there were some areas of the diaphragm that weren't producing near the SPL of other areas. The far field result was that for midrange and higher frequencies, the SPL was not that affected although there was some phasiness induced from the multi-source effect. For low frequencies, the areas of the diaphragm not receiving as much driving force were being driven backwards by the areas around them that were receiving full driving force, resulting in diminished bass authority.
After cracking the panel open, I could see damaged areas in the coating that were leading to the problem.