Polishing compounds for stainless steel (mild abrasives))

[Simon Williams 3Participant @simonwilliams3]

Evening All.

I’m trying to polish a sliding stainless steel shaft measuring 3/4 inch diameter by about 10 inches long to a mirror finish. It’s the control shuttle of a dual diaphragm air operated trash pump, and slides lengthways in two concentric oilite bushes.  The stainless rod does not appear to be hardened  as I can mark it with a file.

Due to operating in a horrible environment, with an air supply that is filtered (but let’s get real) down the last remaining coal mine in the Forest of Dean, the control shaft is scratched albeit only lightly.  I’ve got pretty much got all of the scratches out with 1500 grit wet or dry paper using paraffin as a wash, then used Solvol Autosol to give a polish to the surface.  I can measure no discernible reduction of the nominal 3/4 inch diameter so the rod is a good sliding fit in its oilite bushes and lip seals.

But it’s not a mirror finish yet.  So my question is this:

Is Brasso a finer abrasive than Autosol?  What about silverdip or jeweller’s rouge?  Any other suggestions such as Cif cleaner, or Diamond lapping paste – if so what ball park screen number would be approximately equivalent to the Autosol?  Other suggestions please?

I look forward, as ever, to the collective expertise of the forum

Regards to all Simon

[bernard towersParticipant @bernardtowers37738]

My My Simon in my book what you want to do is impossible without a change in dia but in the past I have used two pieces of hardwood hinged at one end and a hole bored in to suit, remove asmall amount of wood to enable a plier type action and add abrasive of choice.

[noel shelleyParticipant @noelshelley55608]

I think your over doing it Simon ! Any abrasive WILL remove metal and it will be undersize. Do the best you can with solvol and leave it alone, there oilite bushes. Noel.

[Howard LewisParticipant @howardlewis46836]

If it needs to be said, after polishing, which will remove metal (Hopefully hundreths of a thou rather than thous) wash the shaft thoroughly, least any abrasive gets carried over into the soft bushes.

You might try finishing with a “Scotchbrite” pad  in the hope of producing the final polish.

Howard

[Neil LickfoldParticipant @neillickfold44316]

A mirror finish won’t do very much in reality. You will want to have some type of dust seal and ideally some exhaust air blowing the dust out of the seals too. Polished with a pair of Vee blocks and 1200 paper will be good enough. Depending on the state of the shaft stock before hand and how round it is. It may require a courser grade to cut down to the root diameter of the defects. A light grey scotch brite pad, will reduce the amount of micro burs on the surface finish of the bar stock after using the 1200 paper. Polishing with 1200 paper will reduce the diameter by Ø0.01mm

[Mike HobdenParticipant @mikehobden70671]

Pink Stuff is a milder abrasive than Autosol or Peek. I finish my planishing hammers on a piece of leather (from the back of an old sofa!) stuck to a piece of wood. It’s water soluble and cleans off easily.

[VicParticipant @vic]

I’ve used this company a few times, they may have the information you require?

https://www.thepolishingshop.co.uk

 

[Peter Cook 6Participant @petercook6]

I use Simichrome to polish the pivots on clocks. It produces an excellent mirror finish. There is an experiment write up here comparing Simichrome to traditional burnishing for pivot finishing*. The surface finishes look comparable under a 1000x electron microscope.

At the other end of the spectrum Kurtis at CEE recently showed a job linishing a hydraulic cylinder using a toolpost grinder and a flap wheel – I was surprised at the finish achieved using 80 grit!

*The use of abrasives to finish clock pivots produces almost as much argument in the clock world as the question of the oil!

[roy entwistleParticipant @royentwistle24699]

I’ve used toothpaste in the past

[Howard Lewis]

On Howard Lewis Said:

[…]

You might try finishing with a “Scotchbrite” pad  in the hope of producing the final polish.

Howard

NEVER use “Scotch-brite” without testing it first !

The real product comes in various grades … and gawd-knows what’s in the fakes.

MichaelG.

.

Ref.  https://www.model-engineer.co.uk/forums/topic/slip-gauge-question/#post-580774

[Michael GilliganParticipant @michaelgilligan61133]

Oh well … so much for the forum migration

🙁

MichaelG.

.

Edit: __ This is only the ‘consumer’ page !!

https://www.3m.co.uk/3M/en_GB/p/c/b/scotch-brite/

[BazyleParticipant @bazyle]

Many years ago I read about making telescope mirrors by amateurs. The target finish is scratches to be fractions of a wavelength of light.
For the final stages of polishing the glass mirror blank the process was to drop some jewellers’ rouge solution into a tall glass tube of water and wait a while. It gradually sinks with larger heavy particles sinking fastest creating a stratified distribution. Simply insert a tube and syphon off gently each inch of the water which can be evaporated if need be to concentrate or provide dry medium.

[malcolm wright 3Participant @malcolmwright3]

Silvo wadding is a gentler polish than Brasso as it is meant for silver and gold,

If it ends up a fraction undersize a possible option would be to get it hard chrome plated.

 

[Russell EberhardtParticipant @russelleberhardt48058]

Try Micro-Mesh, available from 1500 to 12000 grit.  Used with water and a little detergent it lasts much better thanordinary wet and dry paper and can quickly get you to a mirror finish.

Russell

[Martin KyteParticipant @martinkyte99762]

3M Lapping film is available from 60 to 0.05 micron grain size. Used for polishing the ends of fibre optic cables amongst other things. My other suggestion is leather charged with metal buffing compound as used on grinder polishing mops. Anything from Tripoli to Rouge.

[Michael GilliganParticipant @michaelgilligan61133]

I have just been re-reading the excellent article on making Hairsprings

[May and June issues of Horological Journal ]

There is brief reference to using polishing sticks of Gentian-wood in conjunction with Autosol … This conjured half-forgotten memories, so I had a browse:

https://www.boley.de/en/shop/6087.cleaning-sticks/1838287156.polishing-wood

https://www.cousinsuk.com/product/gentian-wood-swiss-pegwood

MichaelG.

.

Edit: __ Must find me a Gentian Tree !!

[Michael GilliganParticipant @michaelgilligan61133]

https://lettresdubrassus.blancpain.com/en/issue-21/yellow-fairy

MichaelG.

[Author]

Posts