ESL Diaphragm coating - Page 70 - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 9th December 2012, 03:42 AM   #691
fperra is offline fperra  United States
diyAudio Member
 
Join Date: Jan 2008
Location: Lakewood, WA
Here are a couple of sources for the mylar:

Mylar Film for Model Airplane Covering|Turner Toys.com

1/4 MIL metalized - FAI - 5.75 - FAI Model Supply

http://domino-35.prominic.net/A55C2D...257A0E00550A19
  Reply With Quote
Old 9th December 2012, 03:55 AM   #692
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
FYI- You Don't want to use Metalized Mylar for a ESL.

Use the clear stuff only.

Thanks for the links !!!

FWIW

jer
  Reply With Quote
Old 9th December 2012, 04:12 AM   #693
diyAudio Member
 
DeltaStar's Avatar
 
Join Date: Mar 2012
Location: Handel SK
Hi Jer, I wonder if the film used to cover windows would work, the stuff you heat gun shrink for inside winter use, it's clear as day and is very strong. Al
  Reply With Quote
Old 9th December 2012, 04:13 AM   #694
fperra is offline fperra  United States
diyAudio Member
 
Join Date: Jan 2008
Location: Lakewood, WA
Quote:
Originally Posted by geraldfryjr View Post
FYI- You Don't want to use Metalized Mylar for a ESL.

Use the clear stuff only.

Thanks for the links !!!

FWIW

jer
You're right ger. I didn't catch the metalized part. But they also have clear. Here's another source:
Products
  Reply With Quote
Old 9th December 2012, 05:50 AM   #695
diyAudio Member
 
Join Date: Aug 2003
Location: Calgary on the Bow
Quote"Hi Jer, I wonder if the film used to cover windows would work, the stuff you heat gun shrink for inside winter use, it's clear as day and is very strong. Al "

This materials is not a suitable choice. You want a C grade Mylar or the equivalent material from an alternate vendor. Mylar is made by DuPont. As it has been explained shrink film provides just enough tension to get the job done. HS 65 Mylar is what your Acoustats uses, it is made by DuPont and is about as good as it gets for quality HS film the stuff you will find in home window insulation kits is not even close.. A proper quality C grade film (capacitor grade) is what you want and is one which will stand high tension. if you can find tensilized film buy it as that is even stronger but is almost impossible to find. In fact I would doubt most vendors who might claim to have tensilized film. A simple stretching frame is all you need but there are a number of good ideas for stretching film in the archives here. I hope this helps. Best regards Moray James.
__________________
moray james
  Reply With Quote
Old 9th December 2012, 09:04 AM   #696
diyAudio Member
 
JonasKarud's Avatar
 
Join Date: May 2008
Quote:
now only if I could find 5um mylar

How do You need, and where do You live?
  Reply With Quote
Old 9th December 2012, 11:37 AM   #697
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
I had gotten some of that window film but never tried it as it was too thick.

Then I had read that the the backing that comes on it that you peel off and discard is what you use and was Mylar.
It may be some kind of PET film but I don't believe that it is mylar.
It seemed to be too soft and stretchy so I never used it.

I still have that very same roll of it 10 years later.

I was looking to build some larger wider panels at the time but I had never built any at all yet.
So that was when I settled on my smaller versions and used what I have as I knew it was the right stuff.
As I mentioned I used model airplane covering's for my very first diaphragms until I had my construction techniques and coating method down pat as not to waste what I do have.

I was using Graphite at the time.
Graphite is a PIA to do and is very hard to get a good consistent coating.
It took a lot of practice to get it right and I wasted a bit of material trying to do so.
Not to mention that it is very messy and it gets on the stator and other piece's where it is not wanted and causes charge leakage issues when it does.


Yes, tensilized mylar is what you want to use as if it isn't then it will keep stretching over time until it finally stops so a mechanical stretcher is a very good thing to have as mechanical stretching is how they tensilize it in the first place.

I have some kapton but it is very expensive and difficult to locate in thin grades as well.
It does not stretch at all like maybe about .5% at most.
Also, It will not shrink using a heat of any temperature unless it starts to burn or melt.
So, A mechanical stretcher is a must and is required for working with this material.

I have fancied the idea of using it for some ESL's designed for the high heat environment of automobiles in the summer time as well as the cold.
Mylar's tension changes in in these extreme types of temperature changes and from what I have read Kapton does not.

Since this is a thread about Diaphragm Coatings, Stator Coatings must not be over looked as well !!!!

This cannot be stressed enough as I have done quite a bit of research on this subject.

I have had to replace more than my share of precious mylar diaphagms due to burn holes because of stator coating failure.
My last panel that had burned up still had it's original mylar and licron diaphragm that I made for it 10 years ago.

Have you given this some thought?

Checkout the my latest pictures of arc testing my new stator's here,

A Segmented Stator Desktop ESL

Although this new panel won't be run at at 13.6kv of bias voltage, the voltages across the stator's will easily reach and exceed these values.
10kv is my goal for 100% stability as I was their before and above this the voltages becomes very very difficult to contain.

It wasn't the High Bias voltage alone that killed the last panel as it was only at about 6.5kv at the time it had burned.

It was the added voltage out of the transformer at about + 25kv p-p on a high frequency peaks across the stators is when the breakdown occurs mostly.
Remember, I had only a .075" D/S.

This is not so much of a problem for larger ESL's as it is for a smaller ones.
This is due to its larger surface area as they rarely need to be driven that hard to reach the same high SPL's.


FWIW

jer

Last edited by geraldfryjr; 9th December 2012 at 11:53 AM.
  Reply With Quote
Old 10th December 2012, 11:38 AM   #698
Bazukaz is offline Bazukaz  Lithuania
diyAudio Member
 
Bazukaz's Avatar
 
Join Date: Nov 2005
Location: Vilnius
Send a message via Skype™ to Bazukaz
So, let's go back to the original topic .

I was curious about the nylon coating quad used in their quad 57 and refurbishing process to more or less similar specs as the original.
There is an "Electrostatic Speaker Conductive Coating Elvamide 120g" on sale in EBay.
However there are different grades of elvamide with different moisture content.
Table below suggests that 8023R/8066 are preferable(0-5%) and 8061/8063(0-0.7%) are not.
Also the datasheet says that 8061 comes in 3 mm cubes(and is the only type which comes in cubes). Since elvamide on e-bay also comes in cubes my conclusion is that they are selling 8061 and this should not be suitable as a coating.
Any experience?

Regards,
Lukas.
Attached Images
File Type: png Elvamide_datasheet.PNG (40.8 KB, 119 views)
  Reply With Quote
Old 10th December 2012, 12:40 PM   #699
oshifis is offline oshifis  Hungary
diyAudio Member
 
Join Date: Mar 2004
Location: Budapest, Hungary
I am not sure if this has been cited along this thread (sorry if it was):

OriginalCoating
  Reply With Quote
Old 10th December 2012, 04:54 PM   #700
diyAudio Member
 
brian t's Avatar
 
Join Date: Apr 2002
Location: england
Have been using the ebay elvamide recently and although it works its not easy to get a uniform coating and it does not dry very transparent so i am waiting to try some turtle wax f21 as suggested by tyu which should arrive in a couple of days.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
PCB coating rs1026 Parts 10 2nd December 2011 11:08 PM
ESL Diaphragm Coating - HELP GlidingDutchman Planars & Exotics 9 14th March 2008 10:53 AM
Help with diaphragm coating furly Planars & Exotics 6 17th January 2006 08:23 PM
Diaphragm coating Bazukaz Planars & Exotics 9 15th January 2006 07:27 PM
ESL diaphragm coating I_Forgot Planars & Exotics 58 4th April 2005 05:54 AM


New To Site? Need Help?

All times are GMT. The time now is 04:58 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2