a good insulator to brush/paint on?

[szzuk]

Can anyone recommend a good insulator to brush on? I'm thinking of using writers correction fluid/tippex, will it be any good. I need to prevent arking, not sure if i spelt that write, but anyway i have current paths about 20 um apart that need to be separate.

 

[dr pepper]

I dont think tip ex or whatever would have a high enough dielectric.
You can get varnish desgined for motor windings (but needs to be 'baked'), and I use anti corona laquer from rs comps which is sposed to have a good dielectric.
Whats the application?

 

[szzuk]

Its a piezo part that i have re-worked myself, the layers of pzt are now exposed and 20 microns apart so i need something like the laquer you have mentioned, i can bake up to probably 120 degrees c. Regards szzuk.

 

[dr pepper]

Might do the trick, smooth off any edges as much as you can, sharp edges attract arcs.

 

[szzuk]

I looked at the laquer and could only find it in a spray. Might try some nail varnish too. Anything else? Regards, szzuk.

 

[kinarfi]

silicone bath tub caulk or similar?

 

[szzuk]

The silicone sounds a good idea. Thanks.

 

[Mr RB]

You need something with quite a low viscosity to get good wetting (and no air gaps) at such a small distance. I would try super glue (cyanoacrylate).

 

[chemelec]

The silicone sounds a good idea. Thanks.

MAKE SURE YOU GET A "NON-ACIDIC" type Silicone.

Most Silicones are Quite Acidic and will Corrode Wires and Parts.

 

[KeepItSimpleStupid]

Boron Nitride paint: **broken link removed**

Properties: https://accuratus.com/boron.html 2400 V/mil

 

[szzuk]

So far, the silicone is too hard to work with on a delicate part (too viscous). The tippex is going to peel. The boron nitride noted in the last post looks to be the commercial stuff to use, but i don't have any (might get some). The superglue is showing up all of the imperctions of the exposed pzt but seems fine. The nail varnish is hiding all the imperfections and I can't really tell what is going on underneath but seems fine.

I only have 6 of these parts and I'm a bit reluctant to test because when they short it kills the part. Will think about it till tomorrow. Any thoughts? I'm thinking the superglue is the way to go, atleast i can see the holes that have been filled, maybe the nail varnish is hiding air pockets or similar underneath.

 

[Mr RB]

Of course it depends on your voltages, but the superglue will dry to an acrylic plastic and should be fine for lowish voltages. Nail polish will also dry into an acrylic, the main difference is that nail polish is many times thicker in viscosity and you are dealing with micro stuff, so thin viscosity will soak in much better between small features.

 

[Paul_L]

They make High Voltage Corona dope.