Cleaning Bronze.

[citibhoy]

Firstly many thanks to everyone who has provided advice and sources of information on my various posts up until now,

The refit of Maori continues apace, the electricians start this week so hopefully we will be back in the water for end of April.

I have been aquiring period pieces so as to keep the authentic appearance of the boat. One of whci is a hand pump for the galley sink. its a 1 1/4 inch Whale type manufactured by Munster Simms and company Belfast.. Im guessing early to mid 1920's.

The all moving parts are of bronze, but the end of the handle has a a bakelite bulb and there is a bakelite washer/ spacer ring near the top of the cylinder just where the piston enters the cylinder body.

I would like to use this for our dedicated drinking water tanks, But first obvioulsy need to clean it. ( Mechanically it works perfectly drawing water evenly when primed.)
I am wondering what is best way to do this, to remove the verdi-green internally in such a way as not to dmage the piston ring and or the bakelite parts.

Any ideas gratefully recieved.

 

[Peterduck]

Here in Australia we have a product called "Tarn-off", which is self-explantory, and it works fine. Its principal ingredient is 1.7% Phosphoric Acid, which can also be bought as a rust converter to be applied before painting steel. I would recommend rinsing afterward in a weak solution of household ammonia to neutralise the acid. Check the bore of the pump after removing the verdigris, because there may be pits left where corrosion was deep. A better procedure for the bore may be to use a fairly fine wet-and-dry abrasive paper [say around 220 grit] and work it around inside the bore wrapped around your index finger or a piece of styrene foam. The aim here is to remove the bulk of the verdigris while leaving it in the pits to keep them filled.
Peter.

 

[citibhoy]

Peter,

thanks for your suggestion re the verdigris internally....
in the end someone suggested a coca - cola bath... i was intrigued so tried it last night... Amazing after half hour bath all that was needed was a rub with a veryvery fine grade wire woll and it was all gleaming..... Not sure what it means for the average human who ingests the stuff tho!

 

[Peterduck]

That confirms my beliefs about that product. I showed your reply to my partner, and she wondered if it would dissolve the lime scale that has built up in our toilet. I said that it would be a fine place to put it whether it dissolved the scale or not.
Peter.

 

[Kristal]

Yes, I have recently had cause to use Coca Cola to remove ground-on dirt from some fader knobs at work - immersed in a glass of the stuff, the dirt dissolved completely in under an hour, with the knobs only requiring a perfunctory rinse in clean water to return them to looking like new.

Does it follow, then, that I could possibly use a similar technique for removing verdigris from Crystal's portholes, applying a few layers of coke and then washing off after, say a couple of hours? I have always wanted them to be shiny...