Tuesday, 5 January 2010
How to de-rust a tank
If I had a brain I would have looked inside the tank first and dealt with the light dusting of rust before applying the expensive paint to the outside. But no matter.
I went for a combination of mechanical and electrochemical treatment:
1. Chuck in some dried alpine grit, bung all holes with Blu Tac and wrap the tank tenderly
2. Tumble for 25 mins or so in a cement mixer (packed tightly with cardboard and polystyrene blocks)
3. Hoover out the gravel
4. Fill the tank with baking soda solution and electrolyse it using an old iron chisel as the anode, dangled in the solution. Electrical oomph provided by old mobile phone charger (c.500mA)
5. Flush, dry, add more gravel (washed this time) and shake it about
6. More hoovering and flushing, et voila.
I could have coated the inside of the tank with a sealer but the inside looked pretty good so I didn't bother.