DERUSTING – THE EASY WAY by John Birrell

For members not using the electrolytic method of removing rust fromiron and steel parts, here’s the

information necessary to set up. This method was demonstrated at theFeb. Workshop Night.

You will need:-

A container large enough to suspend the rusty bit(s) without themtouching the sides or bottom.

A packet of Washing Soda from the supermarket

A 12 volt battery charger – 4 or 5 amps rating is plenty

Metal for the anode (the liner inside the plastic container)– zincflashing, stainless steel or plain

steel. Not necessary if you use a metal container. This does,however, require the parts to be hung

from an insulator, eg plastic pipe

Wire to hang the parts from a rod or pipe above the container. Theycan’t touch the anode or the

metal container.

Water straight from tap or tank.

Fill the container with sufficient

water to cover the parts. Add

Washing Soda at the rate of about

a handful per 10 litres of water. It’s

not at all critical.

Connect the POSITIVE (Red)

charger lead to the anode or direct

to the metal container. Connect the

NEGATIVE (Black) charger lead

to the wire(s) holding up the parts.

The above is critical! Note that the

hanging wire(s) must make good

electrical contact with the parts, or

nothing will happen. Turn on

power.

Leave for 24 hours or more (It

doesn’t matter how long you leave

the parts in – onlythe rust will be removed, not the parent metal)

The parts will come out with a black slimy coating which

comes off easily with a pressure cleaner for large bits, or

under a tap with a wire brush for small ones.

It pays to dry and prime paint the parts as soon as possible –

they come out so clean that surface rust will immediately

start if left damp.

SAFETY – Even though it is only 12volts, you are working

around water. Only switch on after all is in place, and

remember to switch off before taking parts out.

The following is very important:- Theprocess gives off

hydrogen gas as the water is slowly consumed. Make sure

that your set up is in a well ventilated space and avoid using

angle grinders in close proximity. The frothy bubbles on the surfacedo explode when grinding

sparks reach them. Learned from experience!!

It is easy to scale this process up to suit large parts. I havesuccessfully treated telephone poles by

building a dam from timber sides lined with Forticon plastic, andusing a larger power supply to get

more current. Once you have used thismethod you won’t want to know about molasses baths!