The dreaded firestain

[glitterandgem]

Hi I have done a cuff bracelet with reticulated silver (1st time ) only problem is a lot of firestain on it , how can i get rid of it and maybe an idea for prevention in future

[Dennis]

The way to reduce firestain in future is to paint the whole thing (warmed) with a flux of your choice prior to soldering or annealing. A simple one is a saturated solution of boric acid from a chemist in alcohol or meths.

The bottle should be kept away from open flames.

As your piece is now textured you can still give it a coat of fine silver by depletion gilding. This consists of heating and pickling repeatedly,five or six times. Dennis.

[glitterandgem]

hi Dennis thanks for that what are the ratios for the mix

[Dennis]

Hi, I was on my way out this morning, so for speed put 'saturated solution'. What I meant was as much boric acid powder as the alcohol will absorb, signalled by there being some at the bottom even after shaking. Dennis.

Other explanations:

1. Repeated heating and pickling gradually dissolves out the surface copper leaving a film of fine silver.

2. You can also in future coat the whole area with flux, to reduce firescale during reticulation.

3. You might consider using reflections silver which will reduce you firescale problems too. Dennis.

[ajda]

Does Reflections silver work for reticulation? I'd recommend Argentium for being firestain free, but the germanium oxide layer that prevents firestain would also prevent depletion of the copper on the surface of the alloy which (if I understand it correctly) is necessary for reticulation.

I'm wondering if you need to do more heating and pickling in the first place to deplete the copper and ensure that your surface layer is near enough pure silver before heating for reticulation. Presumably, then, you wouldn't get any surface firestain at all...?

Alan (from a hotel room in Colombo)

[metalsmith]

Does Reflections silver work for reticulation? I'd recommend Argentium for being firestain free, but the germanium oxide layer that prevents firestain would also prevent depletion of the copper on the surface of the alloy which (if I understand it correctly) is necessary for reticulation.

I'm wondering if you need to do more heating and pickling in the first place to deplete the copper and ensure that your surface layer is near enough pure silver before heating for reticulation. Presumably, then, you wouldn't get any surface firestain at all...?

Alan (from a hotel room in Colombo)

Depleting the copper would be fine, but for reticulation there needs to be a compositional difference between the surface layers and, shall we call it, the 'core' of the piece. Argentium would be firestain free, but part of the copper component is replaced with Ge.

'Reticulation silver' has a higher content of copper, so moving to Argentium (lower Cu) would be going in the wrong direction, sorry!

[Nick martin]

I'd second Dennis's advice about reheating and pickling several times, or as I've recently enjoyed discovering, use Argentium for firestain free work.

Cheers,

Nick