Polishing metal (quicker)

[cherod]

I have found that repeated use of Oxalic acid or any acid on polished stainless causes pitting thus dulling the stainless. When that happens on my tubular handrails I mechanical repolish using my big angle gander as pictured above

I think you are right , will dull down with frequent use , oh and , i dont have a big ( 9” ) grinder , 5” is enough for me

 

[cherod]

This is my stainless-steel polishing setup

https://flic.kr/p/WooWib

https://flic.kr/p/WHVYdu

I now use angle grinders with 5-inch flap discs for prep before final polishing

That an interesting fitting you have on your paddle wheels Do you make them yourself ?

 

[Refueler]

One of my colleagues wanted to use Silver Dip in the lab. Knowing that it came in 100 ml bottles he ordered five. The lady responsible for ordering duly placed it, not checking the volumes. What arrived was 5 x 5 litre bottles. Years later when the lab moved to another building we took 4 full bottles and one that was down about an inch from the top.

Blimey !! I remember as a kid polishing all the metal stuff in our house, bicycle rims, car stuff and we used to buy at least a couple or 3 of the standard Brasso tins per year ...what were they ? about 1/2 pint ??

 

[rogerthebodger]

That an interesting fitting you have on your paddle wheels Do you make them yourself ?

A 5 inch angle grinder is a bit too fast for polishing and you must be careful when using a 5 inch angle grinder with a polishing mop the size I have.

The big angle grinder is much slower and controllable.

If I remember correct the angle grinder fittings came from a tool supplier, but I cannot remember from were.

The thread on an angle is M14 so not a standard thread as available from local suppliers here

The one on my bench polisher i made myself but again some time age

The die grinder is a geared down supplied by one of the popular power suppliers to prevent the flap wheel from flying apart as speed or the die grinder burning out at slow speeds needed for the flap wheels

 

[cherod]

A 5 inch angle grinder is a bit too fast for polishing and you must be careful when using a 5 inch angle grinder with a polishing mop the size I have.

The big angle grinder is much slower and controllable.

If I remember correct the angle grinder fittings came from a tool supplier, but I cannot remember from were.

The thread on an angle is M14 so not a standard thread as available from local suppliers here

The one on my bench polisher i made myself but again some time age

The die grinder is a geared down supplied by one of the popular power suppliers to prevent the flap wheel from flying apart as speed or the die grinder burning out at slow speeds needed for the flap wheels

Vario speed

 

[rogerthebodger]

Vario speed

The issue with Vario speed is that the cooling fan in the power tool runs slower and thus the cooling air flow is reduced so the tool heats up and burns out.

When I started polishing, I did use a standard die grinder at about half speed, but the continuous usage caused the die grinder to heat up too much and took too long ot cool down and it then burned out so I purchased 2 with a gearbox so I could run the motor at full speed which increased the cooling but having 2 I could alternate.

I now use 4 off 5-inch angle grinders with different grit pads so alternate the tools I use allow the tool to cool down

One thing the power tool suppliers don't tell you i about the duty cycle of the electric motor

Understanding Duty Cycle of Motor: What are S1-S10?

 

[stephen_h]

I have used this cleaner.
Gets rid of all stains etc. Apply, leave and wash off.
Then a quick polish with the Autosol - perfect!

 

[Refueler]

I really commend those who use all sorts of abrasives and grades etc .. but for the simple boaty ? I wonder if such is suitable.

I go as far as Oxalic for hull ... bit of Vim / Cilit Bang for general ... Metal polish such as Brasso for metalwork ..

Just saying.

 

[rogerthebodger]

Brasso is an abrasive metal polish but is a very fine abrasive

 

[Refueler]

Brasso is an abrasive metal polish but is a very fine abrasive

Yes I know but usually safe except on lacquered surfaces ...

 

[PCUK]

Scratches are easily removed using progressively fine grades of wet and dry with a multi-tool and sander. When making stainless parts I use a delta sander to begin using 120 grit. This ensures a flat finish. If working on tubes I use the multi-tool with a couple of interface pads to give it a curved surface. Working through the grits up to 800 and after this using an airway buffing wheel on a hand polisher. For small items I use the bench polisher. I have used fine grits up to 2500 to get a near mirror finish without additional polishing. For the fine grits I use Padovac who specialise in 2 and 3 inch discs from 60 up to 5000 grit. These discs work fine on the multi-tool delta pad.

 

[Refueler]

Brasso is an abrasive metal polish but is a very fine abrasive

Vim also is ....

 

[cherod]

The issue with Vario speed is that the cooling fan in the power tool runs slower and thus the cooling air flow is reduced so the tool heats up and burns out.

When I started polishing, I did use a standard die grinder at about half speed, but the continuous usage caused the die grinder to heat up too much and took too long ot cool down and it then burned out so I purchased 2 with a gearbox so I could run the motor at full speed which increased the cooling but having 2 I could alternate.

I now use 4 off 5-inch angle grinders with different grit pads so alternate the tools I use allow the tool to cool down

One thing the power tool suppliers don't tell you i about the duty cycle of the electric motor

Understanding Duty Cycle of Motor: What are S1-S10?

,,, thankfully i dont do much grinding

 

[rogerthebodger]

,,, thankfully i dont do much grinding

So you don't get to the point of getting the power too hot and tend to rest between uses which is OK but when you bet to do the amount or long usage I do it starts to be an issue.

Lost count of how many small angle grinders I have burned out and thrown way

Also increased the HP of the electric motor on my bench pillar drill and lathe/milling machine

 

[cherod]

So you don't get to the point of getting the power too hot and tend to rest between uses which is OK but when you bet to do the amount or long usage I do it starts to be an issue.

Lost count of how many small angle grinders I have burned out and thrown way

Also increased the HP of the electric motor on my bench pillar drill and lathe/milling machine

Glad i am a welder and not a grinder.

 

[rogerthebodger]

Glad i am a welder and not a grinder.

I started welding when I started work in a Engineering fabrication workshop in Smithwick now West Midlands in 1962 only stick or gas welding then

Now I have stick, MIG and TIG welding setup mainly MS or SS welding and grinding to clean up the rough welds.

Polishing is where the long power tool usage stake place and takes the time

I have a local company they do laser/ plasma cutting and any bending I may need that makes it easy for me

 

[thinwater]

The newer pickling methods use citric acid. Some of the best pastes are just thickened citric acid. It will not dull the stainless, and it inhibits future staining. If you don't use a paste, soak a paper towel and wrap it.

ASTM method states 5-10% citric acid for 4-20 minutes at 70-160F. Longer times are for lower temperatures. However, higher concentrations do not help.

 

[thinwater]

May well be the same stuff , although i think hydro chloric , commonly used in welding industry

You do NOT use hydrochloric acid to pickle stainless. A good way to pit and start cracks.

 

[rogerthebodger]

You do NOT use hydrochloric acid to pickle stainless. A good way to pit and start cracks.

I only use hydrochloric acid on mild steel to remove rust followed by phosphoric acid as used in the steel industry for galvanizing car body paint plants and steel tube drawing

 

[thinwater]

I only use hydrochloric acid on mild steel to remove rust followed by phosphoric acid as used in the steel industry for galvanizing car body paint plants and steel tube drawing

Yup.

I recall Bethlehem Steel In Maryland use to ship out about 250 tons of spent pickle liquor each day in their peak. The ferric chloride was used for wastewater treatment (coagulant). Huge place.