Electrolytic Rust Removal

[Parm]

ive heard this mentioned a number of times on the forum and quite interested in giving this a go on a set of antique kitchen scales that I will be restoring soon.

What sort of power supply do I need, how many volts and amps, and how do I connect it all up. Negative to the job and positive to a sacrificial anode.

I think somewhere ive got a 12 or 5v power supply that can deliver 4 amps, will this be any good?

 

[Maker]

Any DC power supply will do, 5 or 12 volts will be fine, you want about 1 amp but it's all fairly arbitrary. The part is negative.

 

[Parm]

Any DC power supply will do, 5 or 12 volts will be fine, you want about 1 amp but it's all fairly arbitrary. The part is negative.

Thanks, I take that if the voltage is lower it will just take longer?

And what about parts that have paint. The job I have in mind is mostly light rust but it does have small amounts of paint. Should I remove paint first or after or will it also remove paint

 

[MattF]

Some paint it'll remove, some it might not. It generally scrapes off easily enough, after being in the vat, if there are any remnants.

 

[Parm]

Thanks guys, I'll post up a new thread with pictures about this little restoration. It's some antique kitchen scales that have been dropped at some point. Upon close inspection it's very well made, all dismantles and can be easily straightened out to fully work again, so might as well restore to its former glory

 

[MattF]

Sounds like a nice project. You may occasionally, btw, come across some types of paint/finish which cling like grim death to the surface. Fortunately they tend to be few and far between, so generally electrolysis will lift most paint. You'll soon know if you've got one of the awkward paints on there though.

 

[Parm]

Just need to work out how to remove enamel from the weighing pan now

 

[Parm]

Sounds like a nice project. You may occasionally, btw, come across some types of paint/finish which cling like grim death to the surface. Fortunately they tend to be few and far between, so generally electrolysis will lift most paint. You'll soon know if you've got one of the awkward paints on there though.

This is giving me ideas, I've got some singer sewing machine legs that will form the base for a table. Will this cleaning method work with those too ?

 

[MattF]

It will indeed.

 

[Shox Dr]

Just need to work out how to remove enamel from the weighing pan now

Not sure how you will do that, It's like glass

 

[Maker]

Thanks, I take that if the voltage is lower it will just take longer?

The speed is dependant on the current, but any more than 2 amps doesn't really have any effect other than warming the water. The voltage just needs to be above probably 1 volt to overcome the resistance in the vat.

 

[Maker]

Not sure how you will do that, It's like glass

The only way that springs to mind to remove that is media blasting, or...
molten sodium hydroxide.

I would recommend the former.

 

[Barlidge]

When I was doing some I used an old PC power supply, worked a treat.

 

[slim_boy_fat]

There's a loooong thread running atm with all the info and what folk use.

 

[MattF]

On the PSU front, this is what I use, for all of the vats, even the large one. Sometimes I'll even have a couple of the vats tunning in parallel.

It's only 2.5A max. output, but I have to be feeling quite fruity to even ramp it up to a couple of amps. Usually limited to 1.5A maximum, no matter what size gear I'm doing. The large vat is approx. 4'x2'x2', if I recall correctly, so as you can imagine, that PSU occasionally works with some decent size gear.

 

[Wendelspanswick]

An iPhone wall wart gives out 1 amp at 5v DC. I have loads of the blooming things floating about.

 

[Fred Moore]

Is there a reason why people don't use Acid brick cleaner.
I got a load of lathe tools given and it works a treat.
Cheap enough and no electric needed.
Just submerge the rusty bits in it over night.
Leave it somewhere outside however as the fumes are quite corrosive so my tub goes in the Log store.

Fred.

 

[Maker]

I think it damages the surface of fine parts, and the corrosive fumes you mentioned. There's pretty much no danger with electrolysis.

 

[Wendelspanswick]

Is there any problems with using copper wire to suspend the cathode and anode in the solution, people seem to be using steel wire for this?

 

[Maker]

No, any wire will do.