Patchy colour on 14ct yellow gold - help!

[Victoria]

I'm currently making a ring using 14ct yellow gold...any ideas why when I file/sand it is it going a red gold colour?! It's not plated. Could it be some kind of fire stain? It has been a heated quite a few times... Here's a photo where you can (hopefully) see what I mean.

5060

I'm lost! How do I get it back to being an even yellow colour all over? It's extra fiddly to get an even finish because it's got raised edges...

Thanks you, any suggestions appreciated :confused:
V

[mizgeorge]

is it recycled gold? I know that's what you generally use, and wonder if that could be the problem?

[Victoria]

Yep, it is recycled. I have found that in general it is a bit redder than newly mined yellow gold but I figured that was more to do with who manufactured it and what they alloy it with...it's been hallmarked so I know it's good quality!

It does seem to end up yellow when polished but I've not seen it go quite so red before in the early stages of filing & sanding...

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[Dennis]

Should the scrap be heated for longer, or perhaps stirred when molten, to get a more even mix?

[Lucie]

Is there any way a contaminant could have been introduced in the casting somehow? That happened with a big batch of my silver castings - had frosted white patches that went right through the metal :(

[Victoria]

Oh sorry, I've not been very clear - I've not recycled it myself. It's from Capella Ltd.

It seems to go redder when I file, almost like I'm taking a top layer off, but I can't be!?

V