Monday, September 20, 2010

Eco-friendly Jewellery Pickle solution.

I have read information and seen comments in forums from many jewellers about how they use "eco-pickle" instead of Sulphuric Acid or Safety Pickle in their workshops, for cleaning metals after soldering or heating. I have never been able to pin down a definitive recipe for this though, or been able to find out how long it takes, how well it works...I've read vague claims about using vinegar and salt but no-one ever wants to give away the details, so I thought I'd experiment and here are the results which I share with you!

I currently use a very small Pyrex dish on a hotplate and a warm, weak solution of Safety Pickle to clean my metal. This consists of salts derived from Sulphuric Acid and comes in dry powder form which you add a little to water. I have through-ventilation in my work shed and on warmer days I have the door open too. It is a very shallow bath which I always top up with more water and pickle salts as it evaporates so I never need to dispose of acid. A more environmentally friendly alternative would be preferable though. So I tried a cup of White Wine Vinegar (mine was really old and had turned a little yellow, as you can see above), mixed with a good tablespoon of salt (I only have Sea Salt in the kitchen).

Above is a bottle warmer that was quite handy for warming baby milk but now no longer needed. I put the vinegar and salt into this as a sort of mini pickle-tank and set it to medium warm (but not hot). The purple weaning bowl on top for keeping puree warm during lengthy feeds, is a handy lid and somewhere to rest your plastic / brass tweezers!


Here is a dirty copper scrap on the left and a dirty silver scrap on the right. I spattered a bit of flux on them too. After quenching, they both went into the warm eco-pickle for about 10 minutes...
...and came out splendidly clean! I was quite surprised, but for me it could have been a little cleaner. There were very mild blotches that the usual pickle would have removed entirely. I used White Vinegar instead of dark malt for the obvious reason that it's helpful to see your pieces and be able to find them again in your pickle. After about 3 days of using my eco-pickle for several hours a day though, the solution eventually became too dark to see into...
...and didn't do anything like as great a job on cleaning the metal. I diluted it with water then poured it down the drain. I have since learned that disposing of it in this way isn't a good idea, because although the solution itself is safe, the metals that it has become saturated with, have turned it into a solution which is now no-longer eco-friendly. To find out about hazardous waste disposal in your area then look to your local authority for details. If you're in the UK then read here.

Things to consider;
  1. Brass also cleaned as well as the copper and silver. I have not yet tried gold.
  2. This solution would be as good in a dish and hotplate as the usual stuff, but I don't know how long the bottle warmer elements will last whilst being subjected to corrosive salt mixed with vinegar. It is normally intended for water into which the bottle of milk is placed.
  3. A stronger white vinegar such as actual pickling vinegar, might be even more effective at cleaning. It is also cheaper and comes in huge jars...I shall be testing this out.
  4. A harsher salt such as refined table salt instead of lovely sea salt, may be a more effective salt to add to the vinegar. Again, also cheaper and comes in large quantities....will be getting some to try.
  5. The smell is actually almost negligible. I was expecting to enter my work shed each day to the waft of a Fish & Chips Shop (and worried that I'd be in a permanent state of desire for fattening chips), but there was no smell. The lid was probably a big factor.
  6. In winter, my usual pickle freezes solid into fantastical crystals and ice-like sculptures (think, Superman's secret cave where he watches those vid's from his homeworld...). I have no idea if this eco-pickle will hold out any better against the British winter.
  7. It can be quite eye-watering if you inhale warm vinegar fumes when removing your piece of work.
  8. You can't just keep topping up the solution, it becomes weaker and darker, so you have to dispose of it somehow.....
  9. Cuff by Ute Decker.
By sheer chance, despite having been wondering about vinegar pickle for a couple of years, just a couple of days after the end of my experiment someone pointed me to the website of London based Jewellery designer maker Ute Decker. A pioneer of sustainable jewellery making, her website also contains a wealth of information on things you can do to make your practise more environmentally friendly, with fact sheets for you to download. She also has 2 versions of the eco-pickle.

I would welcome any comments from those who use some kind of eco-pickle or who have suggestions on the subject.

8 comments:

idreamicanfly said...

I've been using a vinegar and salt pickle for a couple of years now. You can see my recipe here:

http://dreamicanflyaway.blogspot.com/2009/01/to-pickle-or-not-to-pickle.html

I get a lot of comments back from other metalsmiths. I tend to just keep adding salt to the hot vinegar until it super-saturates (which is when it stops absorbing the salt). This makes a very strong pickle. Another reader swears by 1Tbsp of salt for every cup of vinegar. Either way, it's a great recipe. But don't forget, it's still acid! Handle with care.

Dale said...

wow, what great information about pickle! I live abroad and can't find muriatic acid, sulphiric acid, pickle solution, or even pool chemical. These are ingredients i can find... i'll give this a try for sure. Thanks for the help!

Laura Cameron said...

Really interesting experiments, I'm hoping to give this a go when my safety pickle expires. I didn't realise it was you, Fluxplay! I've just linked to Ute Decker over on my blog, such a helpful list of resources.

NAOMI said...

I had never heard about eco pickle, thanks for sharing your experiment - can't wait to try it out myself :)

Lena Echelle said...

I use vinegar, sometimes with salt, sometimes without as a pickle and I love it!! Thank you for the great post!!!

Colette said...

This is fantastic! I had no idea about this option.. thanks for sharing!

PyxeeStyx said...

Thank you for this excellent alternative. I've been sanding the hell out of everything just to avoid pickle. I do all my work in my kitchen with a cat that has free rein of the house. This is a workable solution.

PyxeeStyx said...

It worked brilliantly! Thanks

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