Guide To Water Treatments for Water Wash Paint Booths | Ultrimax | UK

Complete Guide To Water Treatments for Water Wash Paint Booths

Water wash paint booth systems are amazing pieces of kit that allow the painter to spray at full capacity. They can effectively handle a large workload and make overspray cleanup a thing of the past. They tend to be viable only if your business is spraying on mass (think conveyor belts of cabinet doors or runs of steel widgets). Smaller scale operations are more suited to the traditional dry filter spray booth setup. Water wash booths do come with some added maintenance considerations if you want an efficient production line and a safe working environment. In particular, the water system must be treated with chemicals to keep it in prime shape as part of a routine maintenance plan.

The problem with water wash booth sludge

If your water is left untreated, paint sludge from your booth system will create a contaminated and unhygienic problem environment, which can:

Create safety hazards
Increase system corrosion
Disrupt air balance
Increase foaming tendency
Disrupt sludge handling and removal
Clog pipes and pumps
Increase cleaning frequency and costs
Increase bacterial load

Left to their own devices, spray booth water systems become an excellent breeding ground for many types of biological growth that pose both painter health and production efficiency risks:

Painter health - risk of contracting Legionnaires' disease and exposure to hazardous biological odours.
Production risks - the build up of sludge impairs booth efficiency and shortens plant life resulting in costly downtime, wasted energy and higher maintenance, chemical disposal and water charges.

What is Legionnaires' disease?

Legionnaires’ disease is a form of bacterial pneumonia which is spread chiefly by water droplets (that contain a bacteria called Legionella) through air conditioning and similar systems. There is a reasonably foreseeable Legionella risk in water systems that meet the following criteria:

Water temperature between 20-45^oC
System creates and/or spreads breathable droplets
System stores and/or re-circulates water
Water likely to contain a source of nutrients for the organism to grow, e.g. rust, sludge, scale, organic matter and biofilms.

Legionnaires’ disease can be extremely serious and may require hospitalistion.

What are Biological Odours?

Most biological odours are emitted from anaerobic bacteria - those which require an absence of oxygen to thrive. Aside from the obvious unpleasant odour that they create, blooms of anaerobic bacteria cause a host of problems to water wash paint booth systems, including:

Plugging up back sections, spray heads/nozzles and other booth water components
Corrosion, leading to premature component failure, reduced operating efficiency and spiralling maintenance costs.
Worker complaints, lost productivity and health concerns.

If you have a build up of sludge, your booth system smells or has an overly 'off' aroma, it's time to clean it out (remove all solid waste) and flush it with denaturants.

How to keep bacteria at bay

Biological odours can be kept in check when the proper combination of chemical water treatments and equipment maintenance. Your maintenance schedule should include routine clean-up of the system’s water locations where solids tend to accumulate, and the correct use of water treatments.

Water treatments explained

Using the right combination of treatments will help you to maximise production efficiency, reduce costs and optimise your booth’s lifespan. Here’s an overview of the different types of water treatment, why they are imporant and when to use them.

Denaturants (de-tackifier)

Denaturants are added to the spray booth water system to rapidly de-tackify the paint overspray to ensure that it is denatured to the required degree. They make the overspray float or sink, according to the booth’s design, in an easily removable form. Minimal paint will stick to the system when denaturants are used, reducing clean-up downtime.

Flotation Additives - Tak Kill

For larger systems commonly found within automotive tier 1, it is essential to remove the paint from the system on a daily basis. To facilitate this, the booth will have a paint separation system (also known as a Co-Ag system) that allows the operator to skim the denatured paint into recovery sacks. A PEL(polyelectrolyte) floatation additive needs to first be added to the water to raise the denatured paint to the surface. The waste can then be skimmed and safely disposed of, saving time and money on waste disposal costs. PEL is normally used in conjunction with other denaturant products which remove the tackiness of the resins prior to separation and removal.

Buy Gramos TAK Kill denaturant products here.

Biocide Additives

Spray booth biocide is specially developed for complete microbiological protection of the water within water wash paint spray booths. It is particularly suitable for the elimination of offensive odours caused by bacteria in the water.

Anti-foam/pH regulators

Anti-foam/pH regulators are designed to regulate and maintain the correct level of alkalinity to boost paint removal effectiveness. This type of additive is particularly useful when spraying:

Water-borne paints - to reduce the foam created when overspray enters the booth's water recirculation system.
Solvent based paints being denatured in high pH alkaline water treatment solutions.

Choosing the right water treatments for the coating being sprayed (powder coatings vs liquid paints)

Liquids paints will always require PEL to bring the particles up to the surface. Powder coatings float without the addition of additives, so you can omit the PEL. Both liquid paint and powder coat clean-up require denaturant, anti-foam and biocide treatments.