hi,
    i am working on a project building a small quantity of prototype underwater hid lightheads and battery canisters.
i am trying to figure out the best thermaly conductive potting material to fill the chamber in the light head where the balast assm. is to help them stay cool & extend thier lifespan. the chamber is aluminum and will be imersed during operation (at least most of the time), water resistance is very desirable, due to the posibility of flooding of the light head (with salt water), but thermal properties are most important.  also an issue is the fact i will be working in small quantities, so a product that can be purchased in small amounts is important
thanks for any help, as i know nothing about potting materials at this time

thanks,
jason