UKH

[like most people...] I have somehow acquired a two foot diameter heavy hammered brass gong.  It is very tarnished and I am trying to find a way to polish it up that does not require me devoting the rest of my life to the task.  So far, with google's help, I have tried:

- brasso - forget it

- a paste of vinegar and baking soda, let it sit for 30 minutes, use a buffing pad on a power drill... some progress, but see the point above about needing to dedicate the rest of my life to it

- super fine wet and dry sand paper - works well on the high bits of the hammered surface, but short of grinding it all down to smooth, it is not going to work

- autosol metal polish and the drill or a nylon scrub plan - same

Any better suggestions?  Can it be dipped?

In reply to wittenham:

Borrow something like this https://ffx.co.uk/products/draper-draper-sbk22-120-max-psi-22kg-capacity-po...

Make sure your abrasive choice is gentle (if it uses shot and grit, go for a high shot low grit mixture)

Edit: or you might find something that goes on a pressure washer instead

In reply to CantClimbTom:

thank you, I will look into that.   I forgot to add to my original efforts  that i tried a pressure washer as well.  A middle of the range Karcher, so i do not know the strength, but i know i would not want any part of my body in front of the spray wand.  It made about no difference.

In reply to wittenham:

Why just 30 mins?

You can get litres of white vinegar online for very little. Stick it in a bath of the stuff for a day or two. Rinse, repeat. If it doesnt work try electrolysis cleaning, with a small voltage. Let science do the hard work.

I've got to ask...

What are you going to user the gong for? Are you in a prog rock band?

In reply to wittenham:

Agreed that water alone from a pressure washer won't help, but if you can find a gizmo that adds fine grit into the stream of water, now that is what might work!

In reply to dread-i:

because I lack imagination and Google told me to do 30 minutes... but I like your suggestion better.

I am torn between starting my own yoga studio and using it to wake my teenage son in the mornings.

In reply to dread-i:

Oh come on, who hasn't dreamt of having a gong in the kitchen to announce that dinner is ready?

OP: I've used coke (as in Coca-cola) for this purpose in the past albeit on small objects. It might get expensive if you fill a bath with it.

In reply to wittenham:

That's a relief, I though you'd gone all J. Arthur Rank (Gongmam) https://en.m.wikipedia.org/wiki/Gongman and the gong came with a huge beater to use and a pair of shorts to wear.

(Yes as a Londoner I'm aware of the rhyming slang, but I didn't mean that)

In reply to wittenham: Toothpaste, lots of it for a two foot gong. 

In reply to wittenham:

Brass gong?

Are they not usually bronze?

https://www.google.com/search?q=bronze+gong

Probably a bit late, but are you sure you want to remove the 'patina'...? Bronze is often chemically patinated to a brown/green to almost black; see various statues.

https://www.thesculpturepark.com/patination/

In reply to wittenham:

Try the cream cleaner used to clean ceramic hobs

 Comes up sparkling clean.

In reply to captain paranoia:

every day is school day around here.  [thanks!]

this is not so much patina as 'left outside for a couple years, then dragged through the fields behind a tractor' 

In reply to wittenham:

Lemon juice bath ?

I cleaned up a brass chandelier by soaking it over several days in acetic acid. I bought a tub of the acid powder in a DIY shop. Add water and leave to soak. Worked a treat.

In reply to wittenham:

As long as you're not going to be abrasive with it once it's looking beautiful - gold plate it 😁

In reply to wittenham:

Following with interest, as I inherited my grandfather's ( think) brass sextant, which is likewise heavily tarnished. As much a concern is how to reduce or stop future tarnish if I do manage to spiff it up, so I don't have to spend the rest of my life polishing it

In reply to wittenham:

If you really do want to cut the patina off (it sounds like you've started anyway) , Scotchbrite pads will get into the relief much better than paper, probably want 400/600/800 grit for reasonable progress toward a dull shine. For a high polish, start at 800 and put the work in up through the grits and onto polishing compounds.

Alternatively, buy the grits loose or as paste/wax, use buffing wheels and a powertool (one wheel per grit size).

jk

In reply to nufkin:

Lacquer, gold plate or accept it'll need an occasional polish. Keeping sulphurous polluted air and all fingerprints off it will slow the tarnishing to a crawl.

jk

In reply to wittenham:

Soak  in beer, or cola? Ever dropped a penny into a pint? They come out gleaming.

In reply to nufkin:

I have some scientific equipment that’s 70 years old and was clear lacquered when new. It is still fine but if you ever need to polish small areas you will have to remove the lacquer as it will go milky. 

In reply to Siward:

Or maybe this:

https://shop.hdchemicals.co.uk/products/oxalic-acid

In reply to wittenham:

The choice for old coins was always brown sauce.  Inevitably though, that will lead to you wanting bacon butties.

I have a WW1 shell casing that was decoratively patterned by a POW which is in need of a clean-up.  So far, I haven't progressed beyond bacon butties.

T.

In reply to wittenham:

Is there any chance that your gong is lacquered? Is which case things like brasso won't work. 

When I worked in a bar with loads of brass on the bar we used Wenol metal polish, brasso on steroids.

In reply to wittenham:

Were you using the brasso with a cloth or with scotchbrite pads or wire wool? I have always found things come up quite quickly with brasso and scotchbrite, but then I've never had anything as large to polish 🙈 You can get scotchbrite wheels for angle grinders and drills, these will speed the process up, but care would be needed not to damage it or leave swirl marks. Bar keepers friend or the pink stuff are more abrasive and might be worth a try.

I feel like polishing a gong is something which should take a long time. By speeding the process up, you are denying your future self the opportunity to tell everyone who comes into your house how long it took.

In reply to wittenham:

No idea whether it'd work on brass but if you ever need to get rust off chrome - coke ("gentle" acid) + silver foil (gentle abrasive) works a treat

Obviously go for the cheap Lidl/Aldi cola 😁

Lots of good advice, thanks.  I poured a couple bottles of vinegar into it [ie:  the underside], let it sit for a couple days and the tarnish is lifting.  I can now see that someone took something quite sharp to it in the past… like a knife or similar.

Now to tackle the front side.

In reply to wittenham:

I visited Glastonbury Tor earlyish (well around 8.15am) one morning, decades ago, and was delighted to see the hippies trespassing in their tents being woken up by a cackling farmer using a drumstick and a wok. No aggro from him, no "get orf moi laaaaarnd", as presumably the sheer amounts are too much to bother with, so he appeared to have taken to just amusing himself this way  

In reply to Blue Straggler:

Sure it wasn't just one of the hippies engaging in some 'dawn ceremony'...?