Castle ESC Sealant

[dethow]

Hey Guys,
I'm setting up a few Phoenix Ice controllers with cooling and getting them sealed as best I can. I'm using a silcone conformal coating over the electronics. I think I've got that part and the cooling under control.

But my question is in regards to a black silicone around the capacitors that I'm seeing on some but not all of the controllers. Furthermore... I'm even seeing that I have a couple Hydra ICE controllers that don't have this sealant. And some that do. It's black in color and rubbery to the touch like a silicone.

Does anyone know what this sealant is? Does it have to be something special that doesn't conduct or would any RTV sealant do the job? I've looked around a bit and I'm not seeing any sealants like this that are specifically meant for use on electrical boards.

[TRUCKPULL]

Black
https://www.offshoreelectrics.com/pr...=mic-dp270-blk

Clear
https://www.offshoreelectrics.com/pr...prod=mic-dp270

Larry

[NativePaul]

The spray on silicone conformal coatings are rubbish. They are easy to apply, and you can solder through them, but they are so thin they tend to not cover the corners of components and boards and over time get worn through. Castle made great controllers, but they were notoriously not water resistant despite the marketing, hopefully their new one will be epoxy coated with something like the dp270 linked to above which give a much thicker and actually effective water resistance, or encapsulated like their recent car ESCs.

I think the silicon at the caps is not used as a sealant, but as strain relief to stop the legs of the caps snapping off over time with vibrations and jostling. the vast majority of silicone sealants are not suitable for electronic use as they the nasty smell they give off is an acid that is corrosive to copper, even the "odorless" ones for fish tanks have it, just in smaller quantities to avoid killing the fish, there are electronics grade acid free silicones available, 2 I have used are Servisol available from most big electronic supplyers here, and Kafuter available from hobbyking, of those 2 only the servisol would fit your needs with it's thick "no slump" formula, the Kafuter is tofunny for that usage scenario more like a really thick liquid than a firm gell.

[dethow]

Thanks for the info guys. I will get some of that DP270.

Paul,
I am actually applying the conformal coating in liquid form with a small bush. However... after looking at the "How to..." article on OSE, I will probably go ahead and add this DP270 on top of the conformal coating I already did.
That is unless anyone else has a reason why that may not be a good idea?