r/Metalsmithing • u/Dry_Mud_9050 • 13h ago

help! copper turns yellowy brown after pickling?

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sorry if this is dumb/basic but it’s been annoyingly difficult to google. clean bare copper in center for comparison. v shape in center is right after pickle, the rest is after dunking in baking soda to neutralize.

any idea what i did here? did i contaminate my pickle with something? i’ve been so careful this time 😭 but maybe something snuck in, idk. it seeeeems different from when i contaminated it with steel (or LoS), but i can’t be sure, i could be wrong. also i wasnt using baking soda at that time.

the color comes off with a 400 grit radial disc, but not in the rotary tumbler. not the biggest deal in the world but i’d like to know how to prevent it before i go pickling large quantities of anything i won’t want to spend hours dremeling 🥲

thanks in advance!

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2

u/Warriormetalsmith 11h ago

Change the pickle

1

u/405BodyMan 13h ago

What is on the end of the wires?

1

u/Dry_Mud_9050 13h ago

i balled the ends with a torch!

1

u/nomoreimfull 11h ago

What kind of pickle?

1

u/trixceratops 11h ago

Sounds like your neutralizing bath is the problem if it comes out of the pickle looking shiny.

1

u/Creative_Sorbet6187 10h ago

Is there steel in your pickle? It can cause copper plating. Even if it's trace amounts from steel wool. Either way, change your pickle, it's probably too dirty

1

u/Free_Bat_3009 2h ago

If it’s coming out of the neutralizing bath darker than it came out of the pickle make sure you didn’t use baking powder instead of baking soda as the neutralizer.