High strength Dielectric Coatings, fact or fiction

[geraldfryjr]

I just found a site that said Shelac only has a 200V per mil break down factor.
I thought is was much higher than this.
Polyurathene or acyrlic is up into atleast the 400V to 500V per mil range or better.
I will research this more and let you know what I find.

I do know that shelac does have higher dielectric constant though but not so much higher to warrant it's use for a large panel.
But it may work very well for head phone drivers though.

jer

P.S. Actually it is not quite bad at all !

http://www.shellacepc.com/properties.html

[geraldfryjr]

Here is a great list of Material properties,

Boedeker Plastics : Material Selection Guide

According to this list Kynar is 1700V/mil, WoW !!
This confirms my testing of this material.
With a Dielectric constant of 8.5.
This looks very inviting for those whom like to use the wire method of building stators !
Hmmm.............


I have been wanting to try Kynar covered wire wrap wire and this might justify the cost of its use.
1700V/mil is the highest I have ever seen for a wire.
The last time I had searched for magnet wire or wire in general,I don't think that I have found this type of rating at all.

jer

[geraldfryjr]

Is This for real?

Kynar Wire Wrap 30 awg - PVC Hook Up Wire

1000' for $37.50 !

It is normaly $30 for 320' which is more than $4.17 for 50' at radio shack.

jer

[moray james]

Ger the second set of panels I ever built for my 0ne plus 0nes were 30 gage kynar wire wrap and those were excellent panels. Great deal. Best regards Moray James.

[bolserst]

Originally Posted by geraldfryjr

According to this list Kynar is 1700V/mil, WoW !!
This confirms my testing of this material.
With a Dielectric constant of 8.5.
This looks very inviting for those whom like to use the wire method of building stators !

Yup, on paper Kynar has always looked to be a step above PVC for ESL stator insulation in terms of dielectric constant and bulk resistivity. As far as the 1700V/mil...remember the insulation thickness on most Kynar insulated wire is 5mil. Most PVC wire has 15mil thick inulation. With PVC having a dielectric strength of about 550V/mil, the overall dielectric strength of Kynar insulated wire is essentially the same as for PVC insulated wire.

[geraldfryjr]

That is Great News,moray james!
I will then consider this for a future build,and to try using segmentation as well.

I wish we could get this stuff as an easy to apply coating!


jer

[moray james]

you can if it`s a coating on wire. You might also look into hypolon (sp?). I admire your hard work and dilligent effort. Don`t get me wrong at one point I was looking into building my own powder coat box and an oven to build panels. Best regards Moray James.

[geraldfryjr]

Yes,I am trying to find it on some Steel wire like copper plated TIG wire or something.
This way they could be self/semi supporting and/or not as fragile.

I have seen tube material available but this is still a bit costly.

Cost factor is my main goal when I do my researches as you can't go wrong with the technology no matter what form of construction you use.

jer

[dochungwell]

James, At no time did I mention Shelac, I did however mentioned that I tested a piece of brass coated with primer, paint and then Polyurethane.

In my controlled test, essentially full insulation of the material using 1 coat of primer, 1 coat of black polyurethane and 4 coats of clear polyurethane. This provide the resistant coating of just under 3kv bias voltage.


Doc

[moray james]

sorry must have been in another active thread where Shelac was mentioned. A white primer as a base coat may well provide some de stressing to the overall coating as the oxides will be conductive enough to let the charge move over a larger area rather than build up in one spot. This technique is employed in high voltage cable designs for the same reason. Hope this is of interest best regards Moray James.