Cleaning Rusty Tools with Citric Acid.

[Mike Hill]

A few years  back I has alot of complex machine parts to clean the rust off.I discovered the technique on the internet of a mild citric acid solution.Citric acid granules are available from Home Brew shops or EBay.

 

It works best when heated in an ultrasonic cleaner but impressive results can be achieved with just a bucket,some citric acid granules and warm water.

 

Firstly just tap off the loose rust with a hammer,degrease your part if needed.Take two handfuls of "Citrol" Chuck them in the bucket (wear gloves if you have any nicks or cuts on your hands) place or suspend your item in the bucket and then cover with 5 litres of water.Double the control for 10 litres and so on.

 

The rust will begin to dissolve immeaditatly,leave it 24 hours and hopefully you will see a nice clean part.If not,just leave it for longer.The acid will just act on the iron oxide and not the steel.When satisfied  remove the items,rinse in the sink,then run enough water to cover them and add a good bit of baking soda to stop the reaction.

 

Dry your parts then protect immeaditatly against corrosion using any kind of mineral oil. I use waste oil.

 

This technique will preserve any markings that wire wheels or abrasive techniques may destroy. It is especially useful on fidly things like Augers and Saws. 

[Tom D]

Thats really cool,  I'll be looking for old bits and bobs to try now.

[Paul in the woods]

I've been doing this on old rusty tools as well. Works well on old bits for a brace and bits, axe heads, hammer heads etc.

 

Not sure how it will affect any special finishes and it does stain any wood black.

 

Wilkos sell citric acid fairly cheaply.

 

I can also vouch for the need for gloves if you have any cuts on your hands...

[Mike Hill]

It seems as though the higher tensile the steel is,the more effective the citric acid works.

 

I have had things come out of a bucket looking like new parts.

[Lazurus]

I use this method a lot on Horse shoes prior to welding, I just chuck them in a bucket with warm water and a dollop of citric and leave to stew.

[openspaceman]

6 hours ago, Tom D said:

Thats really cool,  I'll be looking for old bits and bobs to try now.

If you are impatient and the parts not valuable brick acid is fast. I recently used it to clean the rust off a Fuso canter fuel tank  as it also acted as a flux for the solder I used to repair numerous pin prick rust holes.

 

Also sulphamic acid found in descalers , the one I tried left a varnish like surface that did not rust much after.

[Stubby]

20 hours ago, openspaceman said:

If you are impatient and the parts not valuable brick acid is fast. I recently used it to clean the rust off a Fuso canter fuel tank  as it also acted as a flux for the solder I used to repair numerous pin prick rust holes.

 

Also sulphamic acid found in descalers , the one I tried left a varnish like surface that did not rust much after.

I use brick acid as well . ?

[averagearborist]

Vinegar works well at getting the rust off, although the semi-shiny finish on a battered vintage tool can look a bit nasty.

Evaporust is the best product - it pulls the rust off beautifully.

However, get the wire wheel on your grinder or drill and spend a bit of time abrading the rust off and you get an awesome finish - it retains the dark patina. Only good if it isn't too rusty.

The best method is electrolysis - it's not as much of a ball ache as it looks. And it costs pretty much nothing to do.