Parts Cleaning

Basics

• The Removal of Surface Contaminates from Parts
• Although it can be as simple as "wiping something down" or rinsing something off, this typically refers to the practice as a part of a Quality Control Plan / Lab Protocol
• Certain processes are more sensitive to surface contamination than others
  • Painting, Powder Coating , and Electroplating are suseptible despite not being that "high tech" of processes
  • Microfabrication and Micribiology are so sensitive that they must be preformed in Cleanrooms etc
• Note that when cleaned to very high levels, Flash Rusting becomes a concern with certain metals, and thus either there should be little gap between the cleaning process, and the next manufacturing step, or special precautions should be taken, such as applying a temporary Gumming Solution

Methods

Mechanical

• Scrubbing/Wiping etc
  • Can get rid of "bulk contamination" ; still leves behing a thin film or best case scenario a Monolayer
  • Thus it will still fail the Water Break Test
• Media Blasting
  • Can clean off stubborn contamination and even get to a level passing the Water Break Test
  • Short of Dry Ice Blasting , it is an Abrasive process and thus has impacts on surface finish, and can not be used on thin parts
• Surface Preperation (Surface Prep) for Painting etc is essentially this

Chemical

Solvents

• Dissolves Contaminants
• Polar for Polar Molecules, Nonpolar Solvents for Nonpolar Contaminants
  • Most dirt and grime is nonpolar, hence most Cleaning Solutions focus on this, water works well otherwise in many cases
• Misc Scales for "Solvent Effectiveness" although the nuance of each job makes these only marginally useful
  • Kauri-butanol value
• Note that even with a Perfect Solvent, Flow and/or Mechanical Action is needed to remove the Solution of Dirt+Solvent before it Evaporates
• Processes like Spraying or Vapor Degreasing increase the effectiveness of solvents especially
• Dry Cleaning processes such as using Supercritical CO2 are also in this category, more complexity, but more gentle on certain materials

Chemical Reactants

• Certain Cleaning Solutions can be used to turn Residues that won't dissolve, or be scrubbed off into other chemical compounds that can be
• For instance, Bleach can react thin Hydrocarbon Layers allowing the underlinging material to pass the Water Break Test
  • Even Comet Cleaner works quite well for technical applications!
• Various Acids, and Pirranah Solution among other things also fit in this category

Misc

• Plasma Cleaning

External Links

• The Wikipedia Page On Parts Cleaning
• A Video by the YouTube Channel "Applied Science" Titled "How to choose a cleaning solution" ( ~22 Minute Watch )
  • Links Mentioned in the Video / Provided in the Description:
    • A Video by the YouTube Channel "Ronald Walters" Titled "Cleaning With Ethylene Glycol - Engine Parts, Router Bits, Carbide Sanding Drums" ( ~13 Minute Watch )
    • An Article in "Production Machining" Titled "Selecting Solvents for Precision Cleaning"
    • It also mentioned Dan Gelbart
• A Video by the YouTube Channel "Dan Gelbart" Titled "Building Prototypes Dan Gelbart part 6 of 18 Coatings" ( ~22 Minute Watch )