Which epoxy is used in epoxy captivated connectors?

I am looking for a non conductive epoxy to make epoxy captivated connectors. I contacted many companies could not find the right epoxy. Can anyone suggest a non conductive epoxy that can be used with SMA connectors. I am looking to use the epoxy for a sma female / jack 2 hole flange connector. A picture can be seen below.

Can you answer this question?