Electrolytic/Electrolysis rust removal

[oldasi]

Am about to set up a 45 gal barrel, have it on wheels to move from unheated storage portion of shop when not in use to heated ventilated area when I want to use it. No doubt the solution will freeze when not in use and stored in the unheated section of shop, will this freezing damage the solution ???

[Gromit]

I assume you mean a solution of washing soda. (Some people use salt but I wouldn't as it releases chlorine gas).

As to your question I don't know but here is a specification that makes it appear the washing soda might at least partially precipitate out as the temperature decreases: Whether that process would reverse as the solution temp rises again I don't know.

"Solubility in water at 0, 10, 20 and 30 deg C is 6, 8.5, 17 and 28 wt %, respectively."

Eggeman T; Kirk-Othmer Encyclopedia of Chemical Technology. (2001). New York, NY: John Wiley & Sons; Sodium Carbonate. Online Posting Date: 17 Aug 2001

That same source says that heat does degrade the solution but they are talking about above boiling point temperatures so not applicable.

On a related note probably you are aware already but a carbon graphite anode will keep your barrel of solution far cleaner than using steel anodes. Here is a random link from someone using the graphite.

http://www.robotroom.com/Rust-Removal-5.html

[In The Ten Ring]

I have done a ton of electrolysis for rust removal on my truck parts and I have learned a few things.

Mainly, if you can get things media blasted, do so. Electrolysis works and is cheaper than buying a blasting cabinet but it really fails in certain areas.

1). It cannot work on anything but line of sight.
2). It doesn't rough up the surface like blasting will and thus, paint adhesion is not the best.
3). I had to follow up with Evaporust soak to really get rust off, although the two together really cleaned things up.

I never attempted to store the washing soda water more than a few days. Personally, I wouldn't worry about it. Let it freeze, stir it up next summer, and give it a try. But buy a blasting cabinet if you can or pay someone to use theirs.

[special-K]

I don't know but is there any reason you couldn't drop a heater for livestock watering tubs in and not worry about freezing?