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+-- Thread: Citric acid residue (/showthread.php?tid=7262744)
Citric acid residue - RickW - 04-10-2016
Here's a question for those of you who use citric acid for sharpening or removing rust. Have you ever had a whitish deposit develop on your parts?
I have had it happen to me. I put some files in a plastic tub with a citric acid solution(1 cup citric acid/1 gallon water). I left them in the acid for a couple of days and took some of them out. The rest I left in for a couple more days. When I took those out, some of them had a hard whitish deposit on them. It is difficult to remove, so I'm asking for advice on how to remove it. Anyone experience this, and have any advice?
Thanks,
Rick
Re: Citric acid residue - MarvW - 04-10-2016
All acid type fluids will to that to metal. That's why I never use it on a saw blade. Even Evapo-Rust will leave a white scum on the metal, but it can be easily removed for the most part, but a saw blade will still be discolored with a matte finish that is not easy to remove.
The only way I can think of to remove that stuff is with a fine wire brush, by hand.
Were you trying to sharpen the files or just remove some rust?
Re: Citric acid residue - Steve N - 04-10-2016
I have been surprised here to note no one ever suggests throwing rusted metal in a 5 gallon bucket of diesel fuel. Cleans rust, crud, and built up whatever. Wipe it down after, and you will like the look. If you have an odd piece, try it out.
Re: Citric acid residue - RickW - 04-10-2016
MarvW,
I was trying to sharpen them. I had some success.
The white residue is difficult to remove, even with a fine wire brush. I'm wondering if there is a chemical way to remove it.
I'd also like to know what it is. Are there any chemists here?
Thanks,
Rick W
Re: Citric acid residue - wood2woodknot - 04-11-2016
Steve N said:
I have been surprised here to note no one ever suggests throwing rusted metal in a 5 gallon bucket of diesel fuel. Cleans rust, crud, and built up whatever. Wipe it down after, and you will like the look. If you have an odd piece, try it out.
I'm curious if kerosene (similar to the diesel fuel) works the same way?
Re: Citric acid residue - JimReed@Tallahassee - 04-11-2016
I use citric acid in hot water and add a steel bristle brushing. Most of my plane parts are clean in 5-10 minutes. No issues with residue.
Re: Citric acid residue - Herb G - 04-11-2016
Having residue from citric acid tells me you have hard water.
Make a solution of baking soda & water & use that to get rid of the acid residue.
A tablespoon of baking soda to a pint of water should work. If not, increase the baking soda to 2 tablespoons per pint of water.
Shake it up well to mix the BS with the water.
Let me know if this solves your problems.
Re: Citric acid residue - RickW - 04-11-2016
Here is what I'm talking about:
It seems to form on the top side of the tool only.
I'll try the baking soda idea. I'm also going to mix up a new batch of citric acid and discard the old stuff.
Thanks,
Rick
Re: Citric acid residue - Steve N - 04-12-2016
wood2woodknot said:
[blockquote]Steve N said:
I have been surprised here to note no one ever suggests throwing rusted metal in a 5 gallon bucket of diesel fuel. Cleans rust, crud, and built up whatever. Wipe it down after, and you will like the look. If you have an odd piece, try it out.
I'm curious if kerosene (similar to the diesel fuel) works the same way?
[/blockquote]
Those "old wives" I'm sure you've heard of them, say that you will get rust with kerosene, and not with diesel. To be honest I've just always stuck with the diesel, it's worked well. I tried some of that evaop rust, and was appalled at the finish that came out of that mess, same I've seen with citric acid. White chalky, couldn't restore it with oil.
If it's really an old rust bucket I'll start with a vinegar bath, but I like the finish of the diesel better, so I'll leave it in vinegar for 4 to 6 hours, then drop it in the diesel.
Re: Citric acid residue - Steve N - 04-12-2016
RickW said:
Here is what I'm talking about:
It seems to form on the top side of the tool only.
I'll try the baking soda idea. I'm also going to mix up a new batch of citric acid and discard the old stuff.
Thanks,
Rick
That looks scaly. I'd put the tip of that file in some vinegar, see if you don't like that, then diesel, or some heavy oil for just a while. At this point what do you have to lose?