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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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23rd Jan 2018, 12:57 am | #1 |
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Treating corrosion from leaked cells
I'm restoring a WWII-era Record Bond Tester which has suffered badly from battery leakage. The original battery was a single alkaline (NiFe) 1.2 volt rechargeable cell. The corrosion has eaten away much of the internal wiring and has tracked along as far as the movement itself.
The pictures show the sorry state of the connections to the movement, which - amazingly - still works. I would like to remove this corrosion and stabilise the conductors to ensure that it doesn't keep insidiously creeping back, as this type of corrosion is prone to do if not completely removed. With the cell being alkaline, I'm assuming that the corrosion itself is alkaline in nature, so could it be removed by carefully brushing on a dilute acid, such as vinegar or lemon juice, with a modeller's paintbrush and washing off with distilled water? Or does anyone have any other recommended solutions? All advice welcome! Phil
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23rd Jan 2018, 1:04 am | #2 |
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Re: Treating corrosion from leaked cells
Vinegar and distilled water is what I use when this happens. Takes a while and irritates the nose but it's surprising how good the stuff is.
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23rd Jan 2018, 1:34 am | #3 |
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Re: Treating corrosion from leaked cells
Good-oh, thanks Mr B and I'll give it a go.
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23rd Jan 2018, 2:15 am | #4 |
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Re: Treating corrosion from leaked cells
Yes, vinegar works fine. I have an old pickled onion glass jar that I keep vinegar in for this sort of thing. I apply with an artist's paint brush or cotton bud until the fizzing stops, and wash off with tap water, then blow dry using the BLOW facility of an old cylinder vacuum cleaner. Must have dealt with this dozens of times, especially when the kids used to buy what had been expensive, but non-working, battery-powered toys with corroded batteries for pennies at school jumble sales. Vinegar worked every time.
Last edited by emeritus; 23rd Jan 2018 at 2:23 am. |
23rd Jan 2018, 6:22 am | #5 |
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Re: Treating corrosion from leaked cells
I use a strong-ish solution of citric acid (sold for home brewing or winemaking, I think, at least that's where it is stocked in the local Wilkinsons). It doesn't irritate my nose like vinegar does.
The electrolyte in NiFe (and NiCd) cells is potassium hydroxide solution. Often the corrosion is potassium carbonate (it reacts with CO_2 in the air). It will fizz a bit when you put the acid on, but that is nothing to worry about. The green corrosion is probably some copper salt, which will disolve in the weak acid too. |
23rd Jan 2018, 7:26 am | #6 |
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Re: Treating corrosion from leaked cells
Copper nitrate and copper sulphate ( is it to be sulfate now?) Mostly through the fumes of the hydroxide attacking other metal parts.
Will dissolve, you can't always do it but a dishwasher works wonders. Sulphuric acid corrosion is much harder to neutralise. |
23rd Jan 2018, 8:33 am | #7 |
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Re: Treating corrosion from leaked cells
Excellent, thanks for all the advice.
As the corroded item is a moving coil meter movement, I'll pass on the dishwasher idea, Sam!
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23rd Jan 2018, 9:57 am | #8 |
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Re: Treating corrosion from leaked cells
I cleaned a metal battery holder in a Murphy B495 that I thought had had it the other day, in a bath of white vinegar. It came up really well. The white vinegar is purer/stronger and does a far better job.
regards poppydog |
23rd Jan 2018, 5:35 pm | #9 |
Octode
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Re: Treating corrosion from leaked cells
I use a fibre glass pen to remove what I can, then clean the contacts up by brushing on some ACF-50.
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23rd Jan 2018, 10:47 pm | #10 |
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Re: Treating corrosion from leaked cells
I eventually used a 50:50 mixture of white vinegar and lemon juice, something I've used previously for cleaning intricate brass parts on vintage oil lamps. I applied it with an small artists' brush, left it a few moments and washed it off with hot boiled water. Not a perfect end result I confess, but a lot better than what I started with.
I was interested in the ACF-50 but the price rather put me off... Thanks for the all interest and advice. Phil
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24th Jan 2018, 2:48 am | #11 |
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Re: Treating corrosion from leaked cells
That has cleaned up nicely.
Well done. |
24th Jan 2018, 8:35 pm | #12 | |
Octode
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Re: Treating corrosion from leaked cells
Quote:
But you've done a good job of cleaning those terminals up.
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Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW. |
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24th Jan 2018, 8:54 pm | #13 | |
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Re: Treating corrosion from leaked cells
Quote:
B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
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24th Jan 2018, 10:53 pm | #14 |
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Re: Treating corrosion from leaked cells
Well, my original question was a simple one, but as always with the Forum, I've learned a lot more than I expected!
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Phil Optimist [n]: One who is not in possession of the full facts |
25th Jan 2018, 9:10 am | #15 |
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Re: Treating corrosion from leaked cells
One can debate the best chemical to remove battery leakage and oxidisation, but these can themselves cause further damage, leave residues etc. These days I only use mechanical methods to remove the problem. I have a collection of tools comprising small brass and steel brushes, tooth brushes, fibre glass pen, impregnated rubber blocks etc etc. Then I follow up with a coating of Servisol either sprayed on or brushed depending on the application.
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25th Jan 2018, 10:53 am | #16 |
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Re: Treating corrosion from leaked cells
^^^WHS^^^
Except I use silicon grease afterwards.
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....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
25th Jan 2018, 11:20 am | #17 | |
Dekatron
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Re: Treating corrosion from leaked cells
Quote:
B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
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25th Jan 2018, 9:22 pm | #18 |
Octode
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Re: Treating corrosion from leaked cells
No, not while I still draw breath, anyway. Unfortunately there are a lot of Americans and they have made a pretty good job of mangling the English language. Fair enough for them, but it is the English language, after all. They have had a go at the ancient Greek alphabet, too. "Bayter" indeed!
Colin. |
25th Jan 2018, 10:48 pm | #19 |
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Re: Treating corrosion from leaked cells
In general I agree with your sentiment, but in this case the official spelling has indeed been standardised to 'f', which for once is etymologically correct.
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25th Jan 2018, 11:11 pm | #20 |
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Re: Treating corrosion from leaked cells
Well.... when did that happen? I just looked it up and looks like IUPAC gone done it.
B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |