Cleaning copper PCB traces

[Govmnt_Lacky]

Has anyone used White vinegar and table salt mixtures to clean oxidized traces on PCBs? I have some old PCBs that don't want to clean up with good 'ole soap and scotch brite pads.

Anyone else have a proven alternate idea?

[miketbass]

I havent used it on pcbs, but for anything like this i reach for a product called barkeepers friend. It will remove oxidization via a chemical process (oxalic acid) and is very mildly abrasive. This combined with scotchbrite will shine it up in no time. Most supermarkets carry it in the cleaning product aisle.

[Rob Strand]

Has anyone used White vinegar and table salt mixtures to clean oxidized traces on PCBs? I have some old PCBs that don't want to clean up with good 'ole soap and scotch brite pads.

You have to work out what the problem is.  Are you are convinced the scotchbrites are removing material from the surface.   If there is a hard layer of crap on the *surface* then maybe the scotchbrites simply aren't removing it.  So you could use a stronger abrasive (like wet and dry) or chemical means.

I have managed to get crap off stainless-steel using domestic sodium-bicarb in boiling water combined with some light abrasive (like those domestic abrasive creams).   The vinegar method had some effect in this case but it wasn't good.   I haven't used the sodium-bicarb method on a PCB.  You don't really want salt or acid residues soaking into the PCB material because they will become conductive with moisture.  That's why you tend to use alcohol or acetone.

The other option is there is discoloration which has penetrated into the surface  so when you remove material you still see the discoloration.

[Govmnt_Lacky]

Has anyone used White vinegar and table salt mixtures to clean oxidized traces on PCBs? I have some old PCBs that don't want to clean up with good 'ole soap and scotch brite pads.

You have to work out what the problem is.  Are you are convinced the scotchbrites are removing material from the surface.   If there is a hard layer of crap on the *surface* then maybe the scotchbrites simply aren't removing it.  So you could use a stronger abrasive (like wet and dry) or chemical means.

I have managed to get crap of stainless-steel using domestic sodium-bicarb in boiling water combined with some light abrasive (like those domestic abrasive creams).   The vinegar method had some effect in this case but it wasn't good.   I haven't used sodium-bicarb method on a PCB.  You don't really want salt or acid residues soaking into the PCB material because they will become conductive with moisture.  That's why you tend to use alcohol or acetone.

The other option is there is discoloration which has penetrated into the surface  so when you remove material you still see the discoloration.

I am also looking for a solution to clean up copper etched faceplates. If those things sit out longer than 10 minutes, they begin to discolor.

I havent used it on pcbs, but for anything like this i reach for a product called barkeepers friend. It will remove oxidization via a chemical process (oxalic acid) and is very mildly abrasive. This combined with scotchbrite will shine it up in no time. Most supermarkets carry it in the cleaning product aisle.

Thanks! I'll see if I can find it.

[Rob Strand]

I am also looking for a solution to clean up copper etched faceplates. If those things sit out longer than 10 minutes, they begin to discolor.

There must be a common way to do that in industry.  The easiest I suspect is to let it oxidize then use some sort of tarnish remover.   (No doubt there's large scale processes which use gases and crazy stuff like that which aren't home friendly.)

[Govmnt_Lacky]

I havent used it on pcbs, but for anything like this i reach for a product called barkeepers friend. It will remove oxidization via a chemical process (oxalic acid) and is very mildly abrasive. This combined with scotchbrite will shine it up in no time. Most supermarkets carry it in the cleaning product aisle.

I tried the Barkeeper's Friend. I got the liquid paste version. I tried it on a semi-oxidized and unetched PCB first. Looks like it shined it right up. Tried it on a heavily oxidized etched faceplate. Didn't do too good 

I think what I initially said was oxidation on the copper is actually a bad etch job. The acid unevenly etched the copper and caused pitting as well as 'thinner' layers of sporatic copper which is allowing the black PCB material to show through.

Uggg...