Quoted from Skyemont:What solution do you use. My ultrasonic machine seems to do ok but i am not blown away..
Like Pinterest I used a 50/50 Simple green/pre boiled water (recommended by the manufacturer as it takes all the existing bubbles out of the water). Pre-heat my ultrasonic to 60deg (celcius) then 5-7 minutes. Rinse with water.
When the mixture is really clean, it works best. The dirtier it gets, the effectiveness drops off quickly. For small batches I sometimes use the above mixture in a zip lock bag with the parts and put that in the cleaner. That works great because the mixture is cleanest.
Super dirty parts will still need polishing (I use a tumbler). But the US cleaner gets all the surface stuff off.
A lot of guys use a degreaser mixed with water.
You have to be careful of corrosion on some metals using chemicals - the highly alkaline mixtures will corrode some metals - but its a bit of trial and error. I still dont think Ive found the perfect mix.