Quick question on using evaporust on plane parts

[Mike Manning]

This evening I started cleaning up a couple of Stanley No 7Cs I picked up last year. Both have some pretty good surface rust but I don't believe it will cause any serious pitting. On the first one, I put the plane iron, iron cap, lever cap and lever cap and cap iron screws in Evaporust about an hour ago. I've used that only a couple of times. The instructions say to allow the rusty parts to stay in there from "1-12 hours". The 12-hour max will come about 6am. I'd prefer not to get up for that. Will the evaporust cause any harm if it's in there longer than 12 hours?

Thanks!

[Mike Henderson]

I've never had any problems leaving things in for fairly long times. Evaporust only works on the rust - it doesn't do anything to the sound steel. I does seem to leave a coating on the metal but you can wipe that off, if you want.

Mike

[Phil Mueller]

Same here. I’ve left things in for well over 12 hours before with no harm done. Sleep in.

[Stew Denton]

Mike, be aware that the Evaporust will leave a blackish coating on the steel, but as Mike points out, it comes off very easily. I took it off with fine steel wool.

Stew

[Mike Manning]

Thanks for the feedback guys!

[Rob Young]

I've never had any problems leaving things in for fairly long times. Evaporust only works on the rust - it doesn't do anything to the sound steel. I does seem to leave a coating on the metal but you can wipe that off, if you want.

Mike

To that I would add, cover the vessel so that you don't get evaporation. As long as the metal parts are fully submerged, hanging around for more than 12 hours isn't going to be a problem.

[Nathan Johnson]

To that I would add, cover the vessel so that you don't get evaporation. As long as the metal parts are fully submerged, hanging around for more than 12 hours isn't going to be a problem.

Fully submerged is key, otherwise you'll have an unsightly line between the area submerged and the area exposed.

[Steve Kaminska]

Evaporust is phosphoric acid, which will eat away the iron oxide (rust), and leave a phosphate coating (the black stuff) on the bare steel. If left long enough, it will start to eat the steel also, though this might take weeks to happen.

If you are nervous about it, take the parts out of the Evaporust before you go to bed, and put them back in the solution the next day. Any flash rust will dissolve immediately.

The last plane I restored was a heavily rusted Craftsman... I soaked the metal parts in vinegar (6%) to remove the rust. From prior experience, I knew the vinegar would start to pit the parent metal after 12 hours, so I checked the parts every 2 hours. The most heavily rusted bits were clean in 6 hours.

Iron parts soaked in vinegar will flash rust almost immediately, you can watch it happen. I scrub everything with a scotchbrite pad soaked in a baking soda/water solution, rinse with water, and then bake in the oven to thoroughly dry.

[Jeff Heath]

Only Evaporust knows what it is made of, but it is not phosphoric acid.

[John Stankus]

Evaporust is a chelating agent (pronounced key-lating) dissolved in water with a touch of a surfactant (to reduce surface tension i.e. improve wetting properties)

Chelating agents react with metal ions to make a soluble complex.

There is no phosphoric acid in Evaporust according to the Safety Data Sheet.

John (chemistry professor is my day job)


EDIT
Went looking for their patent. Didn't find it but did find a general sketch of the reaction process.

A chelating agent solublizes the iron cations which then react with an organosulfur compound to make a soluble iron sulfate compound freeing up the chelating agent to go and solublize another iron ion.

[Mike Manning]

12+ hours has been just fine for cleaning the plane irons, lever caps, screws, etc. Can I put the brass adjusting nuts in Evaporust to clean them up as well?

[Phil Mueller]

In a word, yes. I’ve done it many times.

[Mike Manning]

In a word, yes. I’ve done it many times.

Thanks Phil!