Best way to clean up brass after soldering

[Chris glover]

Hi Chaps,
I have been doing a lot of soldering of brass parts of late.I was wondering if there is some way of cleaning up the brass presumably some kind of acid?.Im new to this soldering business so making a few mistakes as I go along.
Chris

[Christoffer Ahlfors]

I use citric acid, the kind you can get at the food store. Two or three bags to a liter of water and store in a plastic container between uses. Let your parts sit in it for a few minutes before soldering, rinse with water and solder. Afterwards, use the acid bath again and a brush to clean off the flux and oxide and rinse in water.
Does wonders to the looks. A shame to paint over...

Cheers,
/Chris

[Chris glover]

I shall give that a try!. Thanks

[Fabrice Le Roux]

Hi Chris,

Agree with Christoffer

Avoid the old model engineer's sulphuric acid pickling solution. Way too aggressive, and nasty stuff if it gets on your clothes, let alone more vulnerable bits (skin,eyes etc)

You can get citric acid as 500g powder from chemists in the UK (may need to be ordered especially) but not expensive. Buy a sealable (clip top) type clear plastic container, so you can see how the cleaning is progressing. I think I did a 10:1 mix and basically you could safely leave stuff overnight to pickle.

After several months a cotton wool like detritus starts to appear in the bottom of the container and the acid loses its etch, then it can be safely put down the sink with lots of water.

Depending on type of solder and flux residue you might need to scrub with an old tooth brush to dislodge thicker plaques of flux.

All credit for cleaning up residues, lots of modellers skip this chore then wonder why the paint round joints bubbles and flakes off!

regards
Fabrice