Notes on the use of ultrasound to clean

[eisman]

I recently purchased a small ultrasound tank and have been experimenting with various solutions for common knife problems. Here are some of my results and issues:

1. Dishwashing liquid (Dawn) -

Works well if all you have is oil, grease, dirt, etc. Does nothing for rust. Does not discolor any materials. Cleans bones and plastics deeply (to the point where they need oil to look good).

2. Simple Green -

Does an even better job of removing oil and hardened deposits. Do not use with plated objects as it wants to lift off the plated material. Slightly discolors carbon steels.

3. Coke -

Actually removes light rust. Mot much good for anything else. Requires soap and water bath to follow to remove sticky residue.

4. Hornady case cleaner -

Very aggresive cleaner. Works against rust and everything else. Really cleans brass! But - big issue - leaves all metals other than brass with a copper sheen that need to be polished out. This solution also turns carbon blades black. Basically you end up ith aclean knife, but need to do a lot of polishing to get it back looking right.

This lineman's knife shows the copper color after a 4 minute session in case cleaner:

5. Lymans gun parts cleaner -

I'm still working with this. It's not as agressive as the case cleaner, but it doesn't react with the metals the same way either. It does get oils and grease out. Interstingly it also will remove the copper color left behind by the case cleaner.

Currently I'm using a series of baths to resolve issues. Still looking for an ideal solution. If anyone has something that they find works please let me know. I'll post any further progress as I find it.

 

[severtecher]

Also one of the best and easiest ways to clean ceramic Sharpmaker stones. I have an old Nestea jar that's tall enough for the stones and just use some dish soap and water. Wipe off with some Scotchbrite and they are good as new.

 

[Phydeaux]

Never thought about using Coke for rust removal. Good tip.

I'd be a little cautious using the Simple Green. Note: this is based on my personal observation.

Simple green seems deteriorate the plasticity of certain plastics. I've had it stored in some polypropylene containers and have had the lids crack prematurely. I also used to use it on my car windows until I notices the window gaskets shrinking and getting brittle. I haven't done any specific tests, just what I have observed.

Ric

 

[Bill DeShivs]

The copper color is actually copper plating. Dissimilar metals in certain solutions will plate onto one another. The copper plates out of brass, onto the steel parts.

 

[eisman]

Bill - you're correct. I don't remember my chemistry all that well, but since it's debonding the copper then something else has to be agressively attaching to the oxididation and/or the tin. My guess is either sulfer or arsenic, but there's neither scent. I do wonder if iron oxide could be the waste product.

 

[Bill DeShivs]

It's an electrolytic action between the dissimilar metals, facilitated by somethin in the solution.