Hi,
if it all were that easy, we all had wonderfully working ESLs at home, won´t we?
Sandblasting sounds nice as long as You get the metal sheets back as sheets and not as something warped. Etching is a process that rather takes off of the surface of the flat sides than the edges itself. To get rid of the edges electropolishing would be the solution (not cheap). Etching and e-polish can be useful with regard to the stiction of the coating to the metal.
Cheap powder isn´t good powder, thin powdering, isn´t good powdering.
To get the needed thickness of at minimum 0.3mm (better 0.5mm, especially at the hole edges!) You should look for special formulations that enable a condiderable thicknes over sharp edges. Most powders are not formulated for this condition, but need a radius of several mm for constant thickness.
The next major prob is general coating thickness. Spray painting the powder is not sufficient at all, even if a second maybe third layer could be sprayed on. If You put on further layers of wet painting of a PU-laquer it will work (actually this works excellently
) Only fluidized bed coating would supply for such thick coatings as needed. With this procedure the heated metal is dipped into a powder bath. But(!!) and this is a big BUT! The powder needs a certain temperature for a certain period of time. The metal sheet with its low mass normally cool down too quick to get the needed thickness. Even if You reach the desired coating thickness its not granted that the powder is completely molten! The result can be a uneven surface and -more serious- far lower flashover treshold than what the material specs would indicate (If the powder doesn´t completely melt it leaves tiny ´cracks´along the unmolten microscopic powder globe surfaces and an arc will develop along the surfaces). The stator will still arc through as if there were nearly no coating at all.
This is a very special coating problem, so don´t expect a perfectly working powder coating to be cheap! Expect that many coaters back off, when You tell them what You actually demand!
I´d suggest as a cheap solution to sand the sheet thoroughly but softly and to laquer the metal with a spraygun using clear PU-laquer (this laquer is solvent based, so exect that it stinks as hell and that You´ll be quite high at the end of the day It is used for staircases and boats and a 5L can may cost You 80-100Bucks)
It´ll be a hell of work since You must coat 10 times or more (and most of the laquer is wasted), but at least You can control quality and thickness. And You can reach a near perfect finish and excellent insulation on Your own.
The second solution would be to build a wire stator. Thats the cheapest method and quite reliable too, but it is a lot of work to get a perfectly flat stator.
Not everything that appears easy actually is easy! ESLs are very sensitive to detail solutions...just one reason why only very few try to fabricate and market them.
jauu
Calvin
if it all were that easy, we all had wonderfully working ESLs at home, won´t we?
Sandblasting sounds nice as long as You get the metal sheets back as sheets and not as something warped. Etching is a process that rather takes off of the surface of the flat sides than the edges itself. To get rid of the edges electropolishing would be the solution (not cheap). Etching and e-polish can be useful with regard to the stiction of the coating to the metal.
Cheap powder isn´t good powder, thin powdering, isn´t good powdering.
To get the needed thickness of at minimum 0.3mm (better 0.5mm, especially at the hole edges!) You should look for special formulations that enable a condiderable thicknes over sharp edges. Most powders are not formulated for this condition, but need a radius of several mm for constant thickness.
The next major prob is general coating thickness. Spray painting the powder is not sufficient at all, even if a second maybe third layer could be sprayed on. If You put on further layers of wet painting of a PU-laquer it will work (actually this works excellently
) Only fluidized bed coating would supply for such thick coatings as needed. With this procedure the heated metal is dipped into a powder bath. But(!!) and this is a big BUT! The powder needs a certain temperature for a certain period of time. The metal sheet with its low mass normally cool down too quick to get the needed thickness. Even if You reach the desired coating thickness its not granted that the powder is completely molten! The result can be a uneven surface and -more serious- far lower flashover treshold than what the material specs would indicate (If the powder doesn´t completely melt it leaves tiny ´cracks´along the unmolten microscopic powder globe surfaces and an arc will develop along the surfaces). The stator will still arc through as if there were nearly no coating at all.This is a very special coating problem, so don´t expect a perfectly working powder coating to be cheap! Expect that many coaters back off, when You tell them what You actually demand!
I´d suggest as a cheap solution to sand the sheet thoroughly but softly and to laquer the metal with a spraygun using clear PU-laquer (this laquer is solvent based, so exect that it stinks as hell and that You´ll be quite high at the end of the day
It is used for staircases and boats and a 5L can may cost You 80-100Bucks)It´ll be a hell of work since You must coat 10 times or more (and most of the laquer is wasted), but at least You can control quality and thickness. And You can reach a near perfect finish and excellent insulation on Your own.
The second solution would be to build a wire stator. Thats the cheapest method and quite reliable too, but it is a lot of work to get a perfectly flat stator.
Not everything that appears easy actually is easy! ESLs are very sensitive to detail solutions...just one reason why only very few try to fabricate and market them.
jauu
Calvin
Hi Bigwill,
You really should read calvins advice once over again.
He said:
I´d suggest as a cheap solution to sand the sheet thoroughly but softly and to laquer the metal with a spraygun using clear PU-laquer (this laquer is solvent based, so exect that it stinks as hell and that You´ll be quite high at the end of the day It is used for staircases and boats and a 5L can may cost You 80-100Bucks)
It´ll be a hell of work since You must coat 10 times or more (and most of the laquer is wasted), but at least You can control quality and thickness. And You can reach a near perfect finish and excellent insulation on Your own.
He actually gives us the information to build a good stator that will work perfectly, without any problem and with good sensitivity.
But you have to take the right way and don't try to choose a quick or easy path.
Me , I have always build wire stators, and I really use a simple method.
But it takes some weekends and a clean straight working method, but at the end, if I fire the stators up, I just know that they always work good .
So I just wanted to say , that Calvin gives you the exact simple method, to prepare and coat, with good results a metal sheet stator, and yes it ll take some time
Why should you try again a quick acrylic paintjob instead?
In the end, all quick ore cheap tryouts end up in an expensive and frustrating learning school.
I'm sorry, I really don't want to sound too patronizing, but I see a lot of beginners making the same mistakes over again and it should not be if one just takes the time and do the job thorougly with the tested methods and materials.
Geert
You really should read calvins advice once over again.
He said:
I´d suggest as a cheap solution to sand the sheet thoroughly but softly and to laquer the metal with a spraygun using clear PU-laquer (this laquer is solvent based, so exect that it stinks as hell and that You´ll be quite high at the end of the day It is used for staircases and boats and a 5L can may cost You 80-100Bucks)
It´ll be a hell of work since You must coat 10 times or more (and most of the laquer is wasted), but at least You can control quality and thickness. And You can reach a near perfect finish and excellent insulation on Your own.
He actually gives us the information to build a good stator that will work perfectly, without any problem and with good sensitivity.
But you have to take the right way and don't try to choose a quick or easy path.
Me , I have always build wire stators, and I really use a simple method.
But it takes some weekends and a clean straight working method, but at the end, if I fire the stators up, I just know that they always work good .
So I just wanted to say , that Calvin gives you the exact simple method, to prepare and coat, with good results a metal sheet stator, and yes it ll take some time
Why should you try again a quick acrylic paintjob instead?
In the end, all quick ore cheap tryouts end up in an expensive and frustrating learning school.
I'm sorry, I really don't want to sound too patronizing, but I see a lot of beginners making the same mistakes over again and it should not be if one just takes the time and do the job thorougly with the tested methods and materials.
Geert
Calvin said:Hi,
if it all were that easy, we all had wonderfully working ESLs at home, won´t we?
Sandblasting sounds nice as long as You get the metal sheets back as sheets and not as something warped.
My powedercoating man woukld place the sheets against some steady background if I would ask him...
Geert's right...
acrylic is not what you want to do if you want to do this right. You can futz around till the cows come home and waste a lot of time and money or you can do it right. If you coat the stators with acrylic you will have to remove it if you want to powder coat. If you decide to powder coat you need to use "nylon 66" as this is THE material of choice because it has the right electrical qualities but most importantly because of all the powder coats it will give you the thickest build at the edges which is where you will need it the most. Anything else is a crap shoot (which means when it does not work you are left with crap). Even then I can tell you right now (and I don't care what your friend or aquaintance tells you) yu will have a hard time finding a professional powder coater that has ANY experience doing a job like this or coating this heavy with the necessary even coating thickness. Almost all of these guys coat for esthetics or enviornmental protection of the part NOT for electrical purposes.
I am not trying to put a damper on your experiment or to prevent you from learning, however you need to go into this with your eyes open and a clear head. I spent considerable time on the phone and over the fax discussing this with the company that does the panels for Martin Logan many years ago. They were are probably one of the most high tech and experienced powder coaters in the country. They had a steep learning curve with lots of trashed attempts to show for thier efforts. The point is that you are spending a lot of money to PC a set of stators and to naively expect that the local guy with a powder coat set up will get right the first time is not in your best interest. Even ML has rejects of some percentage with a very experienced coater.
Any Coater can coat your stators and make them look like a million bucks but they probably won't be able to hold back 10Kv. That's not to say that you might luck out and get a good working set of stators, you might, just understand that it will be a matter of luck. Calvin gave you some good advice and I think that I have too. It is up to you to decide what to do. The right way may seem harder and more expensive and it is but it's what will get the job done with the least amount of grief. Like Calvin said if it were really so easy everybody wouldl/could do it for you and that is not the case.
acrylic is not what you want to do if you want to do this right. You can futz around till the cows come home and waste a lot of time and money or you can do it right. If you coat the stators with acrylic you will have to remove it if you want to powder coat. If you decide to powder coat you need to use "nylon 66" as this is THE material of choice because it has the right electrical qualities but most importantly because of all the powder coats it will give you the thickest build at the edges which is where you will need it the most. Anything else is a crap shoot (which means when it does not work you are left with crap). Even then I can tell you right now (and I don't care what your friend or aquaintance tells you) yu will have a hard time finding a professional powder coater that has ANY experience doing a job like this or coating this heavy with the necessary even coating thickness. Almost all of these guys coat for esthetics or enviornmental protection of the part NOT for electrical purposes.
I am not trying to put a damper on your experiment or to prevent you from learning, however you need to go into this with your eyes open and a clear head. I spent considerable time on the phone and over the fax discussing this with the company that does the panels for Martin Logan many years ago. They were are probably one of the most high tech and experienced powder coaters in the country. They had a steep learning curve with lots of trashed attempts to show for thier efforts. The point is that you are spending a lot of money to PC a set of stators and to naively expect that the local guy with a powder coat set up will get right the first time is not in your best interest. Even ML has rejects of some percentage with a very experienced coater.
Any Coater can coat your stators and make them look like a million bucks but they probably won't be able to hold back 10Kv. That's not to say that you might luck out and get a good working set of stators, you might, just understand that it will be a matter of luck. Calvin gave you some good advice and I think that I have too. It is up to you to decide what to do. The right way may seem harder and more expensive and it is but it's what will get the job done with the least amount of grief. Like Calvin said if it were really so easy everybody wouldl/could do it for you and that is not the case.
jrevillug said:
Hi
These are my most recent ESL's , I build 4 of them for my home theater + 2 subwoofers
An externally hosted image should be here but it was not working when we last tested it.
and here you can find a description with a lot of foto's of the building process, in dutch
But the foto's are universal language
The wire I have used here is an old bobin that I had of 24AWG wire-wrap wire with outer width 1mm.
These are older ones, in use in my living room for more then 5 years
An externally hosted image should be here but it was not working when we last tested it.
greets
Geert
Ongelofelijk goed werk Gvy!
Sorry for the dutch, but really very nice work. For people that understand dutch it's a nice read as well, incredibly inspiring!
Still have to start building some myself, but with all the people in hospital right now there's simply no time....
I will build wire stators for sure!
Sorry for the dutch, but really very nice work. For people that understand dutch it's a nice read as well, incredibly inspiring!
Still have to start building some myself, but with all the people in hospital right now there's simply no time....
I will build wire stators for sure!
if you check out...
the two threads on this page (under Moray James) you will find a hole pile of information that I think may be useful.
http://www.diyhifi.org/forums/viewf...start=25&sid=2639e94ba0bcfb5e3ba92c98de2d8b3e
the two threads on this page (under Moray James) you will find a hole pile of information that I think may be useful.
http://www.diyhifi.org/forums/viewf...start=25&sid=2639e94ba0bcfb5e3ba92c98de2d8b3e
Hi,
Thank you for the compliments.
The nails are "wafferhead nails" 1mm x 15mm (plain simple nails with a flat head).
Since the wire is also 1mm, you can simply turn the wire around thet nail to have a distance of 1mm, between the wires.
Nails of 1mm can be hammered in MDF, wood ore multiplex without predrilling.
I have once made stators with 1,5mm wire and I used nails of 1.5mm then. These you have to drill holes before hammering al those nails.
Before beginning I make an autocad drawing of the naildesign.
Watch out because the bottom design is not exactly the same as the upper one.
I print this out and cut the paper with scissors and lay the design in its place. This makes it easy to exactly position all the nails. Afterwards you can take the little paperstrokes away.
Bending the frame:
The framelength is 1240mm.
In the middle , I fix the frame with a clamp.
Unther both ends I put a piece of wood of about 18mm.
I just tension the wires loose and once I remove the clamp and blocks the statorhalf springs back (like a bow) tensioning the wires.
IT STAYS IN A BOW. But then I fix the statorhalf on both ends with 2 clamps, completely flat on my working table. Now the wires are all very tensioned.
Then I glue them on the wooden bars and let it harden for a night.
After releasing the statorhalf it still stays in a very little bowform ( not much).
But that is no problem because the 2th statorhalf has the same tension and once you bold them together (after fixing the mylar etc...) both forces become equal and you have a perfect straight stator with wel tensioned wires.
Geert
Thank you for the compliments.
The nails are "wafferhead nails" 1mm x 15mm (plain simple nails with a flat head).
Since the wire is also 1mm, you can simply turn the wire around thet nail to have a distance of 1mm, between the wires.
Nails of 1mm can be hammered in MDF, wood ore multiplex without predrilling.
I have once made stators with 1,5mm wire and I used nails of 1.5mm then. These you have to drill holes before hammering al those nails.
Before beginning I make an autocad drawing of the naildesign.
Watch out because the bottom design is not exactly the same as the upper one.
I print this out and cut the paper with scissors and lay the design in its place. This makes it easy to exactly position all the nails. Afterwards you can take the little paperstrokes away.
Bending the frame:
The framelength is 1240mm.
In the middle , I fix the frame with a clamp.
Unther both ends I put a piece of wood of about 18mm.
I just tension the wires loose and once I remove the clamp and blocks the statorhalf springs back (like a bow) tensioning the wires.
IT STAYS IN A BOW. But then I fix the statorhalf on both ends with 2 clamps, completely flat on my working table. Now the wires are all very tensioned.
Then I glue them on the wooden bars and let it harden for a night.
After releasing the statorhalf it still stays in a very little bowform ( not much).
But that is no problem because the 2th statorhalf has the same tension and once you bold them together (after fixing the mylar etc...) both forces become equal and you have a perfect straight stator with wel tensioned wires.
Geert
For what its worth, I used rustoleum oil based paint. I applied it with a roller in a pan (essentially dip coating the panel in large excess of paint) and then suspended it horizontally to dry. I used a can of air to blow out areas where the holes in the perforated metal had filled in.
Repeated about 5 times to get a very thick coating. I don't know exactly what the electrical properties are, but I haven't had any problems with arcing and they work fine.
-WRL
Repeated about 5 times to get a very thick coating. I don't know exactly what the electrical properties are, but I haven't had any problems with arcing and they work fine.
-WRL
Hi GVY,
Thanks for sharing your experience with us.
Another question, what is the voltage rating of your 24awg wire?
Would it be ok if I just use ordinary wire-warp wire of a few hundrad volt rating? I recon there won't be insulation breakdown between the stator wires, and the wooden frame will give some air space between the wire and the "outside world".
Cheers
Thanks for sharing your experience with us.
Another question, what is the voltage rating of your 24awg wire?
Would it be ok if I just use ordinary wire-warp wire of a few hundrad volt rating? I recon there won't be insulation breakdown between the stator wires, and the wooden frame will give some air space between the wire and the "outside world".
Cheers
Hi,
It is infact a wire used for telephone applications, so it is not intended to be used for high voltages. It is not PVC insulated , I think Kynar, but I am not shure, because it is an old bobin and I didn't have specs of it .
I have in the past also used PVC insulated wire with voltage ratings of 500V.
This is also perfectly OK.
I have done insulation tests with a high voltage megger up to 5000V, without any problems.
Anyway, here in Belgium and Holland, most of the "serious" diy esl builders make wire stators and use PVC insulated wire.
These are safe and work ok.
So in my opinion, you can use ordinary wire wrap wire.
Geert
It is infact a wire used for telephone applications, so it is not intended to be used for high voltages. It is not PVC insulated , I think Kynar, but I am not shure, because it is an old bobin and I didn't have specs of it .
I have in the past also used PVC insulated wire with voltage ratings of 500V.
This is also perfectly OK.
I have done insulation tests with a high voltage megger up to 5000V, without any problems.
Anyway, here in Belgium and Holland, most of the "serious" diy esl builders make wire stators and use PVC insulated wire.
These are safe and work ok.
So in my opinion, you can use ordinary wire wrap wire.
Geert
An externally hosted image should be here but it was not working when we last tested it.
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