Evapo-rust

Anybody used this stuff? I just got my first supply a week ago and have finished processing the first group of things, and so for I'm impressed. Great way to save old tools and keep newer tools looking good, to refurbish old bolts and other parts instead of buying new ones, and to totally strip items of rust before painting.

Only caveats so far: (1) longer soaking times that directions imply - they say 24 hours will handle toughest jobs, but I've had some pieces take up to 3-4 days, (2) a few items rerust very fast (within 3 hours) after treatment, but not if promptly treated with a rust-preventive agent - not sure what made the items so prone to rust (iron bar and set of files), (3) I don't think it does so well on stuff that's too big or too attached to be soaked - I am starting a job today to test this, where I plan to repeatedly wipe it with the stuff and let it pool on the surface top.

A couple related questions have occurred to me, too, if anybody knows the answers: (1) what chemical process is at work here? (2) is there a cheaper substance that does the same thing - this stuff costs around $20/gal (3) for items to be painted, I'm still using a rust converter as the base coat even where there is absolutely no (visible) rust left - is that wrong?

Not sure on your first question. I've used several rust converters over the years, none of them held up.

I think POR-15 works best. I have it all over my rig.

Nick

Anything that chemically strips metal will leave it bare(no oil, no protective coating). Exposure to ANY humidity, and the metal will almost instantly rust. This is normal.

http://www.rowand.net/Shop/Tools/Electrolysis.htm

:thumbup:

92xjsp said:

A couple related questions have occurred to me, too, if anybody knows the answers: (1) what chemical process is at work here? (2) is there a cheaper substance that does the same thing - this stuff costs around $20/gal (3) for items to be painted, I'm still using a rust converter as the base coat even where there is absolutely no (visible) rust left - is that wrong?

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Well, I'm no expert, but a quick Google search shows that Evapo-Rust rust uses a process called Chelation which forms a bond with the iron oxide then suspends them in solution.

Other chemical methods include using a variety of acids (like phosphoric acid) that alter the iron oxide into something else (like iron phosphate). Or tannin based solutions that also alter the chemical composition and leave behind a black coating that protects the surface.

As for, is using both wrong? I suspect if the first treatment takes care of all the rust, then there's no iron oxide left to react with the converter.

tbburg said:

Anything that chemically strips metal will leave it bare(no oil, no protective coating). Exposure to ANY humidity, and the metal will almost instantly rust. This is normal.

Click to expand...

Yes, but why some materials so much faster than others? Is it stuff that is more pure steel, or a certain kind of steel process maybe? The metal bar wasn't a surprise, it looked like a highly rustable thing, but how about the metal files like you buy at Auto-Zone? What are they made of? They rust almost instantly. Then other stuff you'd think would rust fast, like nails and nuts & bolts steel plates, show no signs of rust now after several days even though I didn't treat them with the rust preventer solution.

It's not a big deal, since the rust prevention stuff seems to work okay for the stuff I care enough about. I'm just curious about why some things act different, it's the new toy effect I guess.

ECKSJAY said:

http://www.rowand.net/Shop/Tools/Electrolysis.htm

:thumbup:

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I saw that, that looked pretty cool. I'd probably blow up the house, though.

92xjsp said:

Yes, but why some materials so much faster than others?

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come on dude, think! maybe get one of those library cards?
differant metal = differant composition. same reason commercially pure aluminum doesnt rust as easy as steel

Saudade said:

Well, I'm no expert, but a quick Google search shows that Evapo-Rust rust uses a process called Chelation which forms a bond with the iron oxide then suspends them in solution.

Other chemical methods include using a variety of acids (like phosphoric acid) that alter the iron oxide into something else (like iron phosphate). Or tannin based solutions that also alter the chemical composition and leave behind a black coating that protects the surface.

As for, is using both wrong? I suspect if the first treatment takes care of all the rust, then there's no iron oxide left to react with the converter.

Click to expand...

I missed the "chelation" reference in my research, thanks for that. Following that line a little further led to an answer to my most $-sensitive question, is there a cheaper home-brew using the same process. Well guess what - MOLASSES and water, at roughly a 1:10 ratio, is supposed to do the trick!

I saw the acid washes, that looks a good bit more messy and a little more dangerous than chelation, especially if molasses works.

On the painting question, I think you're probably right, but since off-brand converter costs about the same as regular paint, it seems worth it for the added protection - there's no disadvantage, is there?

xcm said:

come on dude, think! maybe get one of those library cards?
differant metal = differant composition. same reason commercially pure aluminum doesnt rust as easy as steel

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Hmm, pretty righteous sounding there dude, did your wife just chew you out for some bonehead move? Good response, get online, pass it on.

I fully realize different metals act different (or even "differ-ant", as you say), thus my reference to different steel processes, etc. What I was looking for from you library card holders was a listing of WHICH ones, if somebody out there was familiar enough with the subject to list them out off the top of his head. If not, then yeah I can research it some more and get an answer.

92xjsp said:

I'm still using a rust converter as the base coat even where there is absolutely no (visible) rust left - is that wrong?

Click to expand...

I noticed something interesting doing bodywork on my Vermont cars. After sanding and naval-jellying a rusty areas, I could not see any rust. Then I'd spray it with a rust converter, the kind that turns black when it touches rust. A lot of it turns black, especially in the areas that had the worst rust.

The moral of the story is that just because there aren't big orange chunks flaking off, doesn't mean your metal isn't oxidized. If it was badly rusted to begin with, it's basically impossible to remove it all, so yes, base coat with converter. It may not last forever but it will really slow it down.

Can't say about POR15, I've been meaning to try the stuff for years and haven't gotten around to it.

"Rust never sleeps" --Neil Young