The AM Forum

  I'm repairing a SGC Antenna Tuner, the part I repaired is covered with a flexible high voltage sealer, can anyone recommend a product I can use to recoat those parts?? Thanks!!

   Don't know if this would work for you or not.

   I have no experience with the product but the company states
its water proof, UV resistance along with anti acid alkali.

Operating temperatures  -40 C ~ 100 C   -40F ~ 212F


https://www.g-apex.com/heat-shrink-waterproof-isolation-tape/products-97-15.html (https://www.g-apex.com/heat-shrink-waterproof-isolation-tape/products-97-15.html)

Here is a sealant for swimming pools.  Of course it doesn't mention anything about High Voltages !

https://aquabondadhesives.com/aquaflex-underwater-sealant (https://aquabondadhesives.com/aquaflex-underwater-sealant)

Super Corona Dope

A company called Anti-Seize Technology makes a spray can product called, cleverly enough, Red Insulating Varnish.  It has a bit of flexibility.  I use it when winding high voltage transformers.  I think I bought it on Ebay.
73 de Norm W1ITT

Why not just use RTV Silicone? Don’t think you can generate any voltages beyond its capability.  Thought they use that goop just to stabilize components and keep moisture away?

RTV may not work due to outgassing. Check the specs.

KLC

Liquid Tape.  Multiple applications if you need higher voltage.

--Shane
KD6VXI

They make a silicone rubber that does NOT excrete Acetic acid during curing.
GE at one time made it under the name "Sil-Pruf", iirc.

Picture of the spot?

The RTV you buy at the local aquarium shop  does not excrete acetic acid (aka  vinegar).  Used to repair and  build tanks.
I bought some....and it smells  like vinegar !

Back in the day,  Dow  corning made a spray bomb called...  'HV acrylic plastic'.  I sprayed that stuff on anything..and  everything.  (clear  finish).   Buddy had a variable cap on his shunt fed  160m  tower... that would arc with just 100 watts.   I sprayed it with the DC product.  No more arcing.   Then I dragged over my  1 kw out  amp  ( that had  160m on it)..and we stuffed  1 kw into it for a week, no arcing.

We even tried it on broadcast  air variables on a fellow's FL-2100 B.  ( .030 spacing).  At one point in it's rotation, the plates would rub...and short out.   Ran it fully  UN meshed   and doused it  with the spray bomb.   Once dry,  runs fine at  650 w out...( with plates still  touching..and rubbing).

I believe they don't make it anymore....  I searched everywhere.   Corona dope  would be a 2nd  choice.  But the  spray bomb  was  handy.

Jim  VE7RF 

Dow maybe farmed it out?

https://www.newark.com/gc-electronics/10-8665/acrylic-plastic-coating-ae-11oz/dp/28M9335 (https://www.newark.com/gc-electronics/10-8665/acrylic-plastic-coating-ae-11oz/dp/28M9335)

https://www.newark.com/techspray/2108-12s/conformal-coating-aerosol-12fl/dp/94M4715?MER=sy-me-pd-mi-alte (https://www.newark.com/techspray/2108-12s/conformal-coating-aerosol-12fl/dp/94M4715?MER=sy-me-pd-mi-alte)

https://www.chemtronics.com/konform-ar (https://www.chemtronics.com/konform-ar)

Check specs, MSDS, of course...

                    _-_-

I learned of this company 50 years ago when I had a part-time job in a motor re-wind shop.  We used a number of their products including encapsulation compound and a thin red lacquer type of aerosol can spray.  I'm not familiar with their products today but here it is. The last company I worked for (a power supply company) was buying some of their products  :

https://www.dolphs.com/products/coating/#cont

Perhaps outfits like Grainer, MSC, or McMaster has a sub-set of their products, don't know.