Solder Residue

[Tadd]

Does anyone know how to get the brown residue off of brass after soft solder application? Flux used is zinc chloride and solder was 50/50. Tried hot water, soap and elbow grease but there is still a brown residue on the part. Eventually want to paint the part and am not sure what effect the flux reside will have on enamel. Thanks in advance.

[yf]

I've always cleaned off zinc chloride flux with plain water and a rag right after soldering when the joint is still hot.

Once its cold it becomes difficult to remove.
Hot water and a rag or even scotchbrite always does it though.

If its on a long time (several days)it gets much more difficult to remove. Heating may be neccessary and then cleaning with scotchbrite and hot water.

[Tadd]

Thanks, thats what I thought. I've cleaned the residue before with a rag when it's hot. ie sweate soldering copper pipe. The problem here is assembly, when soldered together does not lend itself to a wipe down when hot. bosses extending out, deep recesses, etc. I was hoping there was a chemical that might disolve the stuff.

[darryl]

I use acetone to clean up after soldering, works well.

[mikem]

When I solder brass instruments, I wipe away the excess with a wet rag and then use a buffing wheel with white or red rouge buffing compound to wear off the rest of it. Solder is softer than the brass so the buffing doesn't cut the brass as quickly as the lead in the solder, but you still have to be careful, or you'll cut ripples in your brass. I think that solder is relatively similar to brass in that it is not easily dissolved in acid so some mechanical removal is about the only way to get rid of it.

[Rotate]

Go to an electronic supply store and buy flux remover, which comes in an aerosol can. It's very commonly used in the electronic industry to remove flux after the PCB has been wave soldered. It's a strong organic solvent, so I guess Darryl's suggestion of using aceton would work also.

Albert

[Thrud]

Buy a brass brush from a jewelery supply place. Duxel makes one that has 4x17 rows of brass wire on a six inch handle (about $16 Canadian beans). This brush is used for touching up gold/silver/platinum after torch work. It does not scratch soft metals, but can leave brass traces on steel. They alao have one in Stainless steel. Another good brush is the GC electronics Stainless Steel flux brush (Aluminum handle - $20 in Canadian beans) this one is handy for cleaning crud out of guns and clips too.