Fire scale

Hello,

I know you're going to get some sort of fire scale with sterling silver more often than not but I wonder if there are any tips on reducing it?

I find that if the wire/sheet has not been manipulated in any way, the fire scale is less or non existent. I.e. a ring made with round diameter wire that has not been flattened or anything does not tend to have fire scale. If the sterling silver is changed in any way, I get fire scale which then needs to be filed/buffed off as the pickle alone does not remove it.

Question 1: Are there any tips with soldering or solution to reduce it?

Question 2: Take a simple circle cut out of sheet, would you expect there to be fire scale after soldering a jump ring directly onto it?

Question 3 (slightly unrelated): I've used silver clay for a couple of pieces simply because I wanted a more 3D look with these pieces as I don't do casting. I've been trying to find out if you can solder sterling silver jump rings to fine silver (once the fine silver has been torch fired)...I could just try it but a) fine silver is expensive and b) I wasn't sure if there was a certain way of doing it really. Any tips would be greatly appreciated.


Thank you as always for anyone that can help. Lou x

(1) yes, fire scale is caused by over heating, so control your flame, cover the whole piece in Boric acid solution and burn off the alcohol this will leave a coating that will help resisting fire scale.
(2) no
(3) Can't see any reason why it would not work , although Metal Clay is not my forte, so some one else better acquainted with Metal Clay will hopefully chime in

Metal clay once fired is still very porous, so will suck up any amount of solder.
So it is best to apply the solder pallion to the jump ring, keep it in close contact and heat the pendent. The transfer of heat will melt the solder and join the two. (Sweat Soldering).
This is also the best way to connect small items with much larger ones. Dennis.

Thanks China. This is very helpful.x

Thanks Dennis.
Regarding the metal clay, would you try to file in a really tiny groove on the clay piece where the jump ring is going to so it slightly sinks into it you see what I mean or would you keep round metal clay as it is and just slightly file the bit of the jump ring which is going to connect with the pendant? Once the solder is melted onto the jump ring would I want to heating over the whole piece until the 2 connected? Thanks x

p.s. I have been watching some you tube videos on using boric acid saying to use denatured alcohol and boric acid powder (50/50 mix). The videos just show you how to make it. 1 person says to burn it off once dipped in the solution, another says to let it dry off as the firing will remove some of the boric powder. I can try both options but what I can't yet find is what happens from then onwards. They don't actually solder the pieces. I am assuming that once the boric acid is fired or dried, you then apply your flux and solder as usual and solder the piece? x

Just a last note, I get a bit nervous buying chemicals I've not used before....I notice Cooksongold don't sell boric acid/ denatured alcohol. Is there a particular brand or place I ought to go to?x

Regarding the first two questions, either way is fine. Just a matter of choice.
Keep containers of flammable solutions well away from flames
Boracic acid and denatured alcohol (or meths)are available from pharmacies and hardware stores, or on line. There are patent products to reduce fire scale, but rest assured that a concentrated solution of this is simplest and best. Dennis.

Prips, FM solution, Firescoff (can't remember what the other commercial solution was that almost everyone else liked but I could never get on with). No flammable components, they're all water based.

Firescoff's not too bad, but FM solution is cheaper by far.

Another solution is Magic Borax (also aqueous), known to some whimsical souls as Magic Boris.
My tests showed that even after several applications there were unprotected patches. Dennis.

Quote:

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Originally Posted by Dennis

Another solution is Magic Borax (also aqueous), known to some whimsical souls as Magic Boris.
My tests showed that even after several applications there were unprotected patches. Dennis.

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That was the one. I probably still have some somewhere.

What about Argotect? I've been looking at flux myself. This is one that cookson stocks and I supposed to help with firestain.
I struggle with grinding the borax cone as my arms are weak, could I get borax powder and mix some into a paste in a jar?

Ah, I forgot the Argotect too. Works reasonably well, doesn't need methanol and doesn't need grinding.

Argotect has a reputation for being hazardous, but then so do many chemicals we use daily.
https://www.kernowcraft.com/usercont...t%20powder.pdf
Dennis.

No reason why you can't mix your own flux with most commercial Flux, borax is the main ingredient, just mix with water, also allows you to make the consistency that you want, just add less or more water,

Thanks china, I'm going to give it a go as all these other mixes seem to be toxic in some way.

What's Magic Borax?

https://www.dynagem.co.uk/products/m...-soldering-dip