There have been dozens of threads on this if you can manage to search the old forum posts.
Otherwise, for anything except the delicate sliding surfaces :
Degrease with white spirit or kitchen cleaner of choice,
Wire brush (machine not just hand),
brush on phosphoric acid (get a gallon off ebay not the expensive proprietary brews)
Wash off after a while (5 mins to 1 hour as you get experienced),
dry quickly to avoid flash rust, inspect and repeat,
coat asap with diluted clear Waxoyle or equivalent car treatment. Don’t use car polish or anything containing silicone. This will protect things until reassembled and will dissolve away in oil.
If painting you will of course have to thoroughly dewax again.
For parts you will handle, like er handles, coat with a pure beeswax polish (not not not silicone furniture polish) not oil to reduce allergies and contamination of clothes etc.

Having tried various acid based rust removers I finally tried Evaporust. I’s not cheap but is re-usable and it really does work. As with any other treatment you need to de-grease first and tread with water displacing fluid ( what WD 40 was made for) as soon as the part is rinsed or it will rust immediately.

Robert.

On 29 October 2023 at 17:04 Robert Atkinson 2 Said:

Having tried various acid based rust removers I finally tried Evaporust. I’s not cheap but is re-usable and it really does work. As with any other treatment you need to de-grease first and tread with water displacing fluid ( what WD 40 was made for) as soon as the part is rinsed or it will rust immediately.

Robert.

Yes I’d go along with that, Evaporust really does work well.
I think it’s a good idea to thoroughly de-grease before using it, as well as to use a wire brush to get most of the rust off first, to save depleting the active chemicals.
Maybe use a soft wire brush if there are engraved scales, such as on a micrometer or vernier calliper.
I’ve just used it very successfully in de-rusting a completely unusable 40″ vernier by making a long thin tube out of sink waste pipe, blocking one end with a nylon plug and leaving the vernier immersed for a couple of days.

It’s expensive, so I only use it for the more delicate jobs, those cutting tools etc will be fine with a wire brush and some Scotchbrite.

Bill

Evaporust can be re-used but store part used solution in a separate container. Don’t pour it back in with unused in the original container. Ideally filter the used evaporust before storing it. A coffee filter will do the job. And while it is non-toxic always mark containers.

Robert.

If you’re cheap, like me, molasses will work. It acts as a chelating agent, as does Evaporust

A saturated solution of oxalic acid. is less aggressive to the steel than phosphoric acid.

On 29 October 2023 at 23:57 Grindstone Cowboy Said:

Just for info, I was in our local branch of The Range the other day, and they are selling Evaporust 5 litres for £39.99. No recommendations or otherwise implied

Rob

Having tried, and failed, to find Evaporust listed by The Range … I guess I will need to go to Rhyl and have a look.

Meanwhile, a Google search [rather naightily]turned-up this:

https://www.onbuy.com/gb/p/5-litre-rust-remover-solutionsprayliquid~p80488295/?variant=80489959&size=5-litre

which seems to be a ‘knock off’ in the fine tradition of some supermarkets.

… has anyone seen a comparison test ?

MichaelG.

.

Edit: Manufacturer’s web-page:

https://flowchemuk.com/product/rust-remover/

On 31 October 2023 at 08:21 Michael Gilligan Said:

On 29 October 2023 at 23:57 Grindstone Cowboy Said:

Just for info, I was in our local branch of The Range the other day, and they are selling Evaporust 5 litres for £39.99. No recommendations or otherwise implied

Rob

Having tried, and failed, to find Evaporust listed by The Range … I guess I will need to go to Rhyl and have a look.

…

 

Update: Yes, ‘The Range’ at Rhyl had two on the shelf … near to the ex-Wilko painting and decorating stuff.

MichaelG.

On 30 October 2023 at 17:20 Mark Rand Said:

If you’re cheap, like me, molasses will work. It acts as a chelating agent, as does Evaporust

A saturated solution of oxalic acid. is less aggressive to the steel than phosphoric acid.

People get mixed results from Molasses, probably because it comes in many different types.

Molasses is a generic name for a by-product of extracting sugar from different plants.   It varies from a sticky brown semi-liquid to a thick black tar like substance.   Cleaned up versions are sold as a human feed product, others are processed again to make Rum or Industrial Alcohol.   The coarser varieties are widely used as a cheap cattle-feed additive.   As sugar is extracted from different vegetables, grown in different climates, the anti-rust properties of left-over Molasses probably varies enormously.

I think the type that works best on rust is made from Sugar Cane (grown in hot countries), and the most likely source is Cattle Feed, not the supermarket molasses sold for cookery.

I’d happily try Molasses if I owned a cattle farm, where it’s cheap, readily available, and might work.  As I’m not a cattle farmer I’d would have to go well out of my way to buy agricultural Molasses, with no guarantee it would work.   And it’s sticky messy stuff.  For the alternatives are a much better bet.

For what it’s worth, I suggest rust removal falls into four main categories:

1. Hefty lumps that can be cleaned without damage by harsh mechanical abrasion – sandblasting etc,
2. Robust lumps that aren’t damaged by electrolytic cleaning.  (Works well, but needs a bath and power supply)
3. Moderately delicate, requiring a graduated approach like that described in Bazyle’s answer.  (Much used in my workshop)
4. Delicate, where parts are easily damaged, requiring gentle chemicals.  Evaporust and similar are good for small parts, like clock repairing.

Molasses straddles cases 2 and 3, but only if it works! I guess most useful on a farm, where rusted machinery can be left soaking in some handy cattle-feed without bother.

Dave