[Amps] Liquid cooling

[Fuqua, Bill L]

   Thermal conductive is directly related to the electrical conductivity in metals.
Silver conducts heat better than copper and so on. 
    Copper is good becasuse it is easy to solder to and plate unlike aluminum.
Stainless still is very bad due to the fact that it has a very low thermal conductivity
and difficult to drill and solder to. 
    A good and easy way to make a heat sink is to get some thinwall copper tubing
and you can even flatten it slightly to improve the contact with the copper plate and
solder it to the plate. As long as the path of the water flow is very very long compared to 
the ID of the tubing all of the water will be involved in the heat transfer.
   Soft solder is OK but silver solder would be best to solder the tubing to the plate. Since it
has much higher thermal conductivity than lead/tin and most lead free solders. 
    Most of the heat transfer in an automobile takes place in a water path only about
8 or 10 inches at most.  They have to be able to transfer as much as a half megaWatt of 
power thru heat transfer even more for very large cars and truck. We are talking about less than 1kW. 
   Just think of the scale of things.
  
I like to think of examples and scale them up or down to get some a ball park idea of 
what is required to achieve a particular goal.  And if you work with a ball park figure 
you can use it to do a reality check for your calculations or many time just take the ball park and 
multiply it by a factor of 2 or 3 and use that.  

   Rocket science is not always necessary to achieve a particular goal.

By the way. Copper works quite well, look at all the copper anodes on water cooled tubes.
Water has the higest heat capacity that you can get for a reasonable cost and safety.
Antifreeze reduces the heat capacity. Plateing the inside of copper tubing may be tricky but
an interesting idea. Gold would be best but would eventually go away if it is as thin as most
gold plateings due to errosion from the water and underetching via tiny flaws in the plateing.
73
bill wa4lav