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Here’s a headline you need to hear: Water cleaning is old technology, expensive technology and not necessarily the best answer for the environment.
There, we said it. It’s out on the table. Can’t take it back.
The question is, why did you have to come here to learn this awkward truth?
Because there are a lot of vested interests out there, that’s why. People with interests in selling aqueous systems, selling waste treatment systems, selling chemical additives, selling analytical kits, and so on. There even are regulatory agencies that are so exuberant about the benefits of water cleaning that they specify it in regions which don’t have enough water or enough electricity. That’s just nuts.
 There’s an old phrase that rings true: "When the only tool you have is a hammer, everything begins to look like a nail." That’s exactly how the water-cleaning gurus perceive the world --- "Yes, we can clean that!" they claim. And maybe they can. But it may not be the best choice for you or the environment. They won’t tell you about the huge machine it might take to do it, or the electricity you will buy, or the water treatment system you’re going to need. (Isn’t it thrilling that you need a high-tech sewage treatment plant just to clean your circuit boards?)
Here at Micro Care, we feel that the choice of cleaning technology is a very complex issue which should not be over-simplified. In some applications, water may be the best choice. But it is not the ONLY choice. For many applications there is a better way, a cheaper, simpler and faster way. It’s called vapor degreasing.
What’s Good About Water Cleaning?
In general, aqueous cleaning systems are used most often for (a) cleaning parts that are not very complicated in form (e.g., no blind holes or complicated geometry), or (b) the cleaning requirement is not very stringent; i.e., minor surface residue is acceptable, or (c) the parts are very large or the production volume is extremely high.
 Simple metal stampings are a great example of a product which can be successfully cleaned in a aqueous system. A typical stamping is reasonably flat, thin and does not have any tight cavities or spaces into which the aqueous solvents could be trapped. A bare circuit board or a circuit board populated with only "through-hole" components would be a similarly suitable application.
What Are the Weaknesses of Water Cleaning?
Aqueous cleaning usually is not well suited to applications with one or more of the following constraints:
- Size & Spacing:
- Aqueous systems typically have difficulty getting into and cleaning in and around parts which are extremely small or have extremely small spaces.
- Entrapment:
- Aqueous cleaners resist coming out of tiny spaces.
- Spots:
- Water often leaves unacceptable water spots.
- Compatibility:
- Water cleaning often is not suitable because some components or products are sensitive to the high pressures of water cleaning, the heat of washing and/or drying, or the minor surface residues mentioned above.
- Effectiveness:
- Many common types of contamination are not soluble in water, so no amount of water, pressure and heat can remove them.
- Environmental Problems:
- Water cleaners require a great deal of water and electricity, and produce a continuous discharge of contaminated water.
- Costs:
- While water is usually cheaper than solvents on a per-pound basis, the costs of buying, installing and operating the machines can be far higher than a solvent-cleaning system.
Isn't Water Cleaning Better for the Environment?
There is a perception that solvent cleaning is "environmentally unacceptable" and water cleaning is "green." That's simply not true, and to say "water is greener" is to over-simplify.
For example, one critical environmental problem involves preserving our supplies of clean water. Aqueous cleaning systems need a lot of water. Even small aqueous systems use it in vast quantities. Water can be recycled, but that means expensive waste water treatment facilities. And both the cleaning system and the waste water treatment system need large quantities of electricity of which is generated by the burning of fossil fuels which contribute to global warming. Does this sound "green?"
In contrast, vapor degreaser systems use no water at all, and need no water treatment facility. Some smaller Vertrel® systems can run on household electricity and even the biggest vapor degreasers use only a tiny fraction of the energy of aqueous systems. The simplicity and elegance of the Vertrel® systems are a technical "tour de force" with which water systems simply cannot compete.
In short, vapor degreasing can offer an optimal combination of environmental characteristics as well as speedy, reliable cleaning at relatively low cost.
Isn't Aqueous Cleaning Cheaper?
Sometimes -- but not always. When looking at the TOTAL COST PER PART CLEANED, a well-tuned vapor degreaser -- especially one using Vertrel® solvents -- usually is less expensive to buy and operate than an aqueous competitor.
 Installation costs are a large part of aqueous systems. Up-front capital costs include the actual cost of the machine, freight, site preparation and set-up costs. Most engineers also include building renovations, ventilation enhancements, electrical upgrades and water-treatment subsystems required to support the new system. These expenses can be as costly as the cleaning machine itself.
Once installed, aqueous systems typically have higher operating costs than solvent systems on a per-part basis. On an apple-to-apples basis, including the cost of the solvent, the electricity, labor, consumables (e.g., saponifiers, filters, etc.), and waste disposal/waste treatment costs, vapor degreasers usually come out cheaper except (a) when cleaning the simplest parts or (b) cleaning in the very highest volume applications.
Where Can I Get More Information?
You’ve come to the right place. Here’s a few links you might want to check out:
- General Information
- About the Environment and Vapor Degreasing
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