cleaning rust from machine tools ?

[pe2dave]

When I was reading up on this in the winter for the planer I was restoring, I ended up not using it as it looked really fiddly for small parts (with everything having to be in contact with the ?cathode?),

I don't believe that to be the case, the current flow is via the electrolyte from one terminal to the other, no parts need to contact either electrode.

 

[sams93]

I’ve renovated a few machines
, and tried most systems. I prefer the electrolysis method the most. It’s unbelievable cheap, and it only removes the rust no matter how long you heave the stuff in the ‘soup’. It’s far gentler on parts and I have to say in my experience better results.

Do you find parts need scrubbing intermittently during the process?

 

[sams93]

I don't believe that to be the case, the current flow is via the electrolyte from one terminal to the other, no parts need to contact either electrode.

This is what makes me think that

 

[pe2dave]

I've seen them used with a cathode as a conductive part, the 'artifact' simply being en-passant?
I may be wrong (as the saying goes)

 

[imageel]

i would also recommend electrolysis, it's super fast and gives a very clean finish, albeit the rusty scum left behind in the bucket is pretty disgusting, I used a couple of pieces of angle iron as the sacrificial +ve electrodes and an old car battery charger as the power source.
I don't have any before photos, however this Record block plane was smothered in surface rust and came up pretty clean after -

 

[pe2dave]

This is what makes me think that

From this youtube, you're quite right. though all your pieces could be hung together if that's a nuisance

 

[deema]

I don’t scrub the parts intermittently, just leave them until the process stops….or longer if I forget them! The onky thing to be very careful about is do not get the connections the wrong way around. The anodes are ‘eaten’ by the process, so if you do, your parts will come out smaller than when they went in!

 

[MarkAW]

Beware it can make tools brittle, and that can be sorted with a slow bake in the oven.
Wear gloves!
This was a good article on it:
https://htpaa.org.au/resources/rust-removal

 

[Henniep]

i would also recommend electrolysis, it's super fast and gives a very clean finish, albeit the rusty scum left behind in the bucket is pretty disgusting, I used a couple of pieces of angle iron as the sacrificial +ve electrodes and an old car battery charger as the power source.
I don't have any before photos, however this Record block plane was smothered in surface rust and came up pretty clean after -

Does it have to be a battery and charger or will a 12volt DC transformer work?

 

[pe2dave]

Does it have to be a battery and charger or will a 12volt DC transformer work?

Needs to be DC so no a transformer won't work unless fitted with a rectifier.

 

[Henniep]

Needs to be DC so no a transformer won't work unless fitted with a rectifier.

Thanks pe2dave - will stick to the charger/battery. No big deal.

 

[Jameshow]

Needs to be DC so no a transformer won't work unless fitted with a rectifier.

Does a transformer not supply 12v DC?

 

[The_Yellow_Ardvark]

This rusty tool came my way as part of a bundle of other tools.

A good example of the power of electrolysis.


I use a old fashioned battery charger, from about the 1970's

Set to 12Vdc, with the positive to the Anodes. Normally scrap steel.

Don't use copper wire to old the parts, it will dissolve. Don't leave the croc clips in the solution either.

I hang the item to be de-rusted from Mig Welding wire in the middle of the container.
I use 1 table spoon of Washing Soda to 1 Ltr of water. I adjust the mix as required.

A past session.

Any plastic container can be used.

I once did a Land Rover chassis in a paddling pool with a Old DC Arc Welder.

After 48 hours it was removed, dried well with a blow torch.

Then with wire wool and a wax/oil mix the black oxide is removed.

The black oxide can be baked on as a rust proof barrier as well.


If not there is always Citric acid.

 

[The_Yellow_Ardvark]

Oh a simple drawing.

 

[Sideways]

I use an old laptop power supply for electrolysis.
21 volts or so dc, and they are protected in case of an accidental short circuit.
I have no qualms about using big crocodile clips to attach the parts being cleaned. They show no signs of harm after many days of use submerged. Just dont use them on the sacrificial end of the circuit.
The chemical reaction seems to draw electrolyte up inside the insulation of stranded copper wires if you use those for connections. It does little harm, it's just odd to find damp at the wire ends that are well out of the solution.
This is my sacrificial plate - it rusts merrily but it's thick so has a while to go.

I'm keeping eyes open for an old wire mesh chip basket or similar to hold batches of small parts and make for an easy connection.

 

[pgrbff]

Many many thanks for all your help - I found I have some citric acid but also found some 'Evapo-Rust Rust Converter' in the shed that I had bought some years ago and forgotten ever to try. I soaked the first batch of parts for about 15 hours, and then also your responses made me realise I could use an ultrasonic cleaner that I had tucked away to further the treatment - and bingo, I can't believe how everything is in fact better that I have ever had them in the past. Now doing every old tool I have around - never tried these processes before - thank you so much, see pictures below:
View attachment 161313View attachment 161314View attachment 161315

I have read that you can damage the bath if the parts are in direct contact with the tank and not in a basket.

 

[pe2dave]

Does a transformer not supply 12v DC?

No. A transformer converts AC from (say,) 240 to 12 AC. It then needs to be rectified to supply the needed DC.

 

[John Hall]

Phosphoric acid is the one to use…it’s what’s in most rust removing products
Stronger and more effective than citric acid….Google it…

 

[peterw3035]

i would also recommend electrolysis, it's super fast and gives a very clean finish, albeit the rusty scum left behind in the bucket is pretty disgusting, I used a couple of pieces of angle iron as the sacrificial +ve electrodes and an old car battery charger as the power source.
I don't have any before photos, however this Record block plane was smothered in surface rust and came up pretty clean after -

Is there a risk of the electrolysis effecting the japanning?

 

[imageel]

Is there a risk of the electrolysis effecting the japanning?

No not really the paint is a pretty good insulator @12V and is inert to the Soda at the concentration required to make it work. I looked just now at that plane and whilst there is the odd chip in the paint, the electrolysis has merely cleaned the exposed metal, and where the paint is pretty thin as on parts of the rough casting around the frog it has had no effect