Ultrasonic cleaning to remove diamond particles

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scooby

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My cylinder liners are cast iron (Howell V4), and I lapped them with diamond paste. I have a ultrasonic cleaner, but I'm not sure what liquid/solvent I put in the tank.
 
I just use hot soapy water in my tank for exactly the job you want to do, but before that I scrub the job with acetone. Prior to buying a us tank I just did several acetone scrubs and I never had problems with diamond retention on my model engines from 0.125cc up to 10cc displacement.
 
I cleaned my ML Midge pistons and liners in an ultrasonic cleaner using hot soapy water. Just dry them and coat them with WD40 or similar when you take them out of the bath.

If you're really worried about rust, place the liners in a glass jar with kerosene and place that in the U/S cleaner. I haven't tried it, but apparently it works well.
 
I wouldn't. I put my test CI liner in ultrasonic with water & cleaning solution, fortunately not too long because I could see it was discoloring (rust). I believe its a no-no to fill the tank with any kind of hydrocarbon based solvent. Have not heard about the jar of solvent within a water bath so cant comment.

Personally I would try a soft nylon bristle brush & WD40 or hydrocarbon solvent paint thinner. I found these worked very well to break down whatever the oil/grease base is for lapping compounds, then the aggregate seems to just go with it. Here are some pics using diamond paste on steel parts with both aluminum & mild steel laps.
 

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I agree with the WD40 suggestion, or white spirit, DERV, or Paraffin as a wash (not in the Ultrasonic machine) before rinsing in detergent water in the Ultrasonic bath. Actually, my favourite solution from the kitchen cupboard is the clear window cleaning spray liquid. What you are doing is lowering the surface tension that holds particles onto the metal surface, so many fluids do that. The common term is simply "wetting". A toothbrush also works well for scrubbing inside bores.
Don't use hydrocarbon fluids in the Ultrasonic machine as explained below. (I have but it is dangerous!). A dentist explained that ultrasonic cleaning of teeth also liberates pure oxygen and ozone locally to the Ultrasonic probe, which in turn sterilises the bacteria in that locality. So the Ultrasonic bath does the same thing.
If you use flamable hydrocarbons in the Ultrasonic cleaning tank, or in a jar/tin in the water in the Ultrasonic tank, then actually the vibration will cause vapour of the lightest, most flammable compounds to be derived, with a risk of ignition at a very low flash point. Depending on what you use, there may also be some oxygen or ozone liberated, so the vapour can be explosive! If it goes "woof" you won't see the flash, and may lose more than your eyelashes! (Just like the oxygen-hydrogen mix liberated from lead-acid batteries when being re-charged).
Take care my friends....
K2
 
How long should I keep the parts in the ultrasonic cleaner? I have an extra cylinder liner I can use to test on
I just set 5 minutes on the timer and that seems good enough. Yonks ago with a different cleaner I left a piston in the bath running overnight and it destroyed the mirror finish on the piston. I have no idea why!
 
I'm surprised you were seeing rust on something that was totally immersed. Generally rusting needs free oxygen. I've never had steel rust on me when I've been cleaning it with soapy water, as long as I dried it and oiled it immediately.
 
The ultrasonic causes dissolved oxygen to come out of solution, so it attacks iron readily. There is also some ozone formed, according to the instructor in the dental hospital. That is very corrosive!
K2
 

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