Leave the IPA for your backyard BBQ!
Do I really need to clean No-Clean flux residues after reworking my board? After manually hand soldering, the residues left on the board may present some potential issues like not fully outgassed, which exposes the active residues that would normally be encapsulated. It could also cause burnt residues due to applying excessive heat which can be a cosmetic eye sore. Lastly, if applying conformal coating, residues can prevent proper adhesion.
Why do I need to angle the board as I clean? You need to do this to minimize or eliminate the risk of contaminating other areas of the board.
Can I clean different types of flux residues with the same cleaning agent? Yes, there are cleaning agents that can be clean a variety of flux residues. However, if you use a solvent you might not be able to clean water soluble (OA) flux residues.
Why do I need a crystal or metal dispensing bottle for my cleaning product? You need a dispensing bottle that is made of a material compatible with your cleaning agent. Many solvents are not compatible, short, or long term with plastics so you will need a crystal or metal dispensing bottle for those.
What would be your recommendation for best manual/hand cleaning method? All methods listed in this presentation can be effective if done correctly but my recommendation would be to wash any reworked board in an automated system as it would provide more consistent cleaning results than cleaning manually. This is because it is operator dependent.