Cathodics

Question 1

What are the principles of cathodics?

Answer 1

2 dissimilar metals are in S/W & connected together,Current flows thru water, from anode to cathode.A basic galvanic cell.The Sacrifical anode dissolves while the cathode (hull) is stable.

Question 2

Dailies on cathodics

Answer 2

• carried out on amplifier assembley
• record current & voltage & ships speed

Question 3

Monthly on cathodics

Answer 3

• ship can be berthed but not beside other ship or stopped at sea
• Readings on hull potential using portable ref electrode 8 foot below waterline

Question 4

Principles of cathodics operation

Answer 4

• Maintain hull at negative potential using reference anode
• Voltage at -0.8 mv
• 2 voltages will make a signal and control current to hull anodes

Question 5

Over protection cathodics

Answer 5

• Blistering of hull paint & brittleness

Question 6

Under protection cathodics

Answer 6

No corrosion protection