So I know rust is an issue for everyone here, and removal is a real desire. The current market leader for rust removal is Evaporust, and it's been around for a while. But it's expensive, right? Remember not long ago, someone posted an alternate maker that they bought at one of the discount stores. Almost drove over to one to get some, but lazy and travel made it never happen.
Then the other day, I this video popped up in my feed- https://www.youtube.com/watch?v=fVYZmeReKKY&t=285s&ab_channel=BeyondBallistics
He did some research, and made his own chelation rust remover from water, citric acid, and sodium carbonate. He also put up the recipe for sodium bicarbonate. Since I was doing wine making a long time ago, I happened to have some powder citiric acid, and sodium bicarbonate is just baking soda. Why not experiment?
Mr_Asa
MegaDork
8/1/24 11:10 a.m.
Not enough of a chemist to say anything intelligent on the matter, but I know one of the reasons EvapoRust is liked is how gentle it is to the material. I also know that you start throwing acids and salts at metals and you often can get weird reactions that are not good for strength.
I'd want more info on the reactions before I tried it on structural members, myself.
So maybe hard to see, but the important part is that the threads are really clean and smooth now. So it works.
Citric acid is cheap to get in volume on the big river outlet, and sodium carbonate and sodium bicarbonate is pretty easy to get locally (one on the laundry area the other in baking).
The one thing I would change is a more neutral soap- I used some antibiotic hand soap, as it was handy vs. a spray dish soap I had. But something really basic without any additives that will act as a surfactant- as I think some of the residue is from the soap additives. Or even a better surfactant only- but I've not researched a neutral surfactant.
Something to consider if you have rust to remove.
Mr_Asa said:
Not enough of a chemist to say anything intelligent on the matter, but I know one of the reasons EvapoRust is liked is how gentle it is to the material. I also know that you start throwing acids and salts at metals and you often can get weird reactions that are not good for strength.
So the guy doing it is a gun restorer (I assume) so not attacking the base metal is pretty important. That's why he added sodium carbonate to the citric acid- to raise the PH and change the chemistry.
Given people have used straight vinegar, which is just acid, I'm less worried about the problems for what I'm doing.
So a little looking up what is happening.
citric acid plus sodium bicarbonate results in sodium citrate and co2.
sodium citrate is a rust inhibitor for steel.
this is an edit. The citric acid is completely changed. And the left over sodium citrate does chelate with the ions in rust- making it soluble in water. Thus dissolving the rust and not reacting with the base steel. Which is how Evaporust works.
How long did you soak the bolts in your solution concoction?
I've been letting them sit for 24 hours.
That's pretty cool. Thanks for sharing!
alfadriver said:
Mr_Asa said:
Not enough of a chemist to say anything intelligent on the matter, but I know one of the reasons EvapoRust is liked is how gentle it is to the material. I also know that you start throwing acids and salts at metals and you often can get weird reactions that are not good for strength.
So the guy doing it is a gun restorer (I assume) so not attacking the base metal is pretty important. That's why he added sodium carbonate to the citric acid- to raise the PH and change the chemistry.
Given people have used straight vinegar, which is just acid, I'm less worried about the problems for what I'm doing.
I used salted vinegar and it derusted the parts I was interested in cleaning very well. (351 Cleveland head and exhaust manifold bolts) They also rusted again extremely fast.
This looks a lot more interesting.
In reply to Pete. (l33t FS) :
Reading up on it, the sodium citrate does leave a protective surface. Supposedly.
I've washed everything with water and then "fogged" them with wd40.
