High strength Dielectric Coatings, fact or fiction

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Spraying it on is a better choice.
It will allow for a more consistent and stronger,smoother coating.
A roller will introduce contaminants and air bubbles into the coating material.
Not to mention what will be wasted in the roller as the stuff is very costly enough.

It does not surprise about the type-o.
Now that have my HV supply done maybe I can one day soon bring some truth to some of these claims!

jer :)
 
I would not use this product until it was tested first. So far my research and my experience has led me to use Hellmans Spar Varnish. It is about $38.00 a gallon and I spray it on applying multiple coats after first applying the primer and black under coats.

Although I should have taken Charlie M's advice to measure the panel thickness layer with a micrometer, my feelings are, regardless of measurements if it arcs. it needs more layers...

Charlies close up views reveal the desired thickness by the visual appearance of "doughnuts connected to one another"....without fillings.

I guess my point was when I began this thread was to hear opinions and products out there in regards to dielectric product claims and truths to those who have first hand experience using them for this practical application.

To me, the common denominator is that one of the best dielectric/conformal coatings is Alkyds, it seems to be the main ingredient present in much of the sprays I have researched and tested. In the future I will begin with a good primer layer, black paint as a base coat, then MULTIPLE layers of Hellmans Spar Varnish Polyurethane.

I will however consider using black Glyptol as a base coat, as this may reduce the overall top coats I would need to apply.

Doc
 
Here is some info on ceramic

Spraying it on is a better choice.
It will allow for a more consistent and stronger,smoother coating.
A roller will introduce contaminants and air bubbles into the coating material.
Not to mention what will be wasted in the roller as the stuff is very costly enough.

It does not surprise about the type-o.
Now that have my HV supply done maybe I can one day soon bring some truth to some of these claims!

jer :)


Wanted to tell you that the spray on brand is available in 55 gallon drums... dipping?
Dry times are probably to fast for that.. probably look ugly. Found your post on the gallon of licron crystal... awesome! Don't need it but still cool to know.

Here is a link that uses ceramic coating.

Dielectric Coatings, Gradated Coatings & Ceramic Coatings for High & Low Voltage Applications | Thermal Spray Technologies Inc.
 
I may have found THE home coating to use. My red insulating spray enamel has a high dielectric rating but their are other problems that relate to home spraying and using this and other products. Right now I KNOW my panels will arc. If you are not a painter I highly recommend getting them painted or powdercoated. The reason is... debri. I find it hard to believe that the problems is the material or brand choice itself. The spaces we are talking about are so tiny that debri and voids are the problem not the material. To a reasonable degree a high quality varnish is a varnish etc. etc. I am curing mine and then resanding them or stripping. The problem is THE DRY TIME OR CURE TIME. It seems to me that this is more important then dielectric rating for home painting your stators. Believing this I went to search for a product where true cure time is shortest and I found a (of course expensive) product that is used to cover motherboard circuitry to protect from electricity. It is called a conformal coating in tech circles. You have to have a mask I believe to spray it.

Besides the fast dry
Aervoe 403 Insulating Epoxy - www.tooldex.com
which is quite cheap and may be best for price if dry time is accurate I have yet to try it.
Below are the conformal coatings I found. (2000 ish dielectric)
PROMTECH AEROSOLS PVT LTD : PRODUCTS : ACRYSIL COATING - QUICK DRYING PCB CONFORMAL COATING
http://www.techspray.com/product-info.php?pId=64&cId=4

This red insulating paint I am using is fast drying but the cure rate takes 3 days. It is very hard at end of that time but unless you have a clean room it is tough to do and not get debri. These conformal coatings mention the problem of sharp edges and are designed for this problem.

I will probably have mine powdercoated however. I recommend this unless you are setup like Charlie with a shop. If you are spray painting in a house where people are walking around... and their is a cat and a dusty garage with stuff piled around.... and you think you can figure out a way... I can assure you by the time you take in the repainting of voids and problems drying and taking off debris etc. etc. Get it powdercoated. I may even strip mine 60 dollars later and go get it powdercoated. Right now for example on each of my four small stators their are at least 4-6 places where a hair in a hole... a void caused by the paint being pulled off... I had no place to hang them... per stator. You paint again... dry... takes forever... money...

My two cents to anyone getting into the game!
 
If that techspray can fully cure in 10 minutes... might be something to try.

That 10 minute cure time appears as a bullet point in the advertising, and depends on coat thickness and requires elevated temperatures.

The balance of the literature for the product suggests full cure in 24 hours at room temperature and less than 60% humidity. Nor do they mention which thickness and what temperature is required for that 10 minute cure, but typical would be "very thin" and "oven baked" for just about any paint-on coating.

The maximum temperature rating is 125C fully cured, so perhaps the quick cure temp is a few hundred degrees F or less, but you'd have to contact them to get the actual values; it's not provided (or even mentioned aside from the bullet point) in their product literature.
 
Yes, This is very true, as my very first samples failed and had a lot of micro cracks,But that was mainly due to receiving the screen rolled up in a tube after it was coated.
I made sure that this did not happen on the second sample.

Also if you are using aluminium has a stator material you may have corrosion issue a few years down the road.
This is the reason that I had to reseal my stators with some clear acrylic after seven years of environmental abuse.
It was the only pair I had made like that,So I didn't get to spend enough time researching the proper procedure with my powder coater guy.
Although these were issues that had occurred seven years after the fact.

I started working on the damaged panel last night so we will find out soon if it is still worth anything,But I have good feeling about it.

I patched it with some super glue and Hard as Nails clear nail polish.


jer :)
 
Here is some very cool information on Coil dope and and other coatings.

Antique Radio Forums • View topic - Nail polish = Glyptol = coil dope?

Nail polish is a nitrocellulose based product and the stuff that has Nylon in it is Nylon 66.
I am not sure if using nylon is good or bad as it has been used as the diagphram coatings too,But it does have a extremely high resistance factor.

Nail polish has always been good as far as insulating high voltages and now I know why. It has been used with other names as well just for that purpose.
I have finally found it in bulk For about $30 to $40 per 32oz. so far.
I know the stuff that you can commonly buy is quite thick and can be thinned and ran through a sprayer.
That was just one vendor I am sure I can find it even cheaper.

http://www.google.com/url?sa=t&rct=...xe2yBA&usg=AFQjCNE19P_sLs5eDOdGAg7Y0UkWKC-Akw


http://www.google.com/url?sa=t&rct=...xe2yBA&usg=AFQjCNG09g8IObNwA5Dk18FPn9gt_t2NsQ

It also has a higher dielectric constant of 6.2 and as high as 7.5,

http://www.google.com/url?sa=t&rct=...xe2yBA&usg=AFQjCNHGF0OweI2wFdg4T-CcFUmHH_g1rQ

some more cool Info,

http://www.google.com/url?sa=t&rct=...xe2yBA&usg=AFQjCNHG82mPZmP7Zq7NLVGykKWe4gDAAw

It is all good!! :)
Cheers !!!

jer :)
 
Here is some more info,
this one claims 2kv/mil,

http://www.eastman.com/Literature_Center/E/E226.pdf

this one is rated at 1500v/mil

http://www.ashland.com/Ashland/Static/Documents/AAFI/PRO_250-42A_Aqualon_EC.pdf

this is a very good read as well and towards the end the CAB type is mentioned,

4hv.org: Printer Friendly

jer :)

P.S There is a guy in that last thread that explains using a two part furniture epoxy,and says that it is better than any of the other coatings that were discussed.

one more great PDF of info,

http://www.ebookbyte.com/admin/uplo...astics Handbook (www.eBookByte.com) Ch-10.pdf
 
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