Bespoke Joinery Manufacturer

Background

The client is a joinery manufacturer producing bespoke cabinetry, alongside fitted and loose furniture. Their finishing operation runs continuously, with multiple sprayers working across primer and topcoat application throughout the working week. The quality of their finish is a direct reflection of the quality of their products, so any change to the spraying system had to maintain the standard their clients expected.

The Challenge

The client was using a two-part PU finishing system consisting of two coats of primer and two coats of topcoat. The finish quality was good and the product applied well, but there were two problems that had become increasingly difficult to manage.

The first was drying time. The product was slow to dry, creating delays between coats and disrupting the flow of production. In a busy finishing department where throughput matters, that time adds up quickly.

The second was smell. The client operated from an industrial unit and neighbouring businesses had begun complaining about fumes coming through the extraction system. That was the solvent. The old system carried a heavy aromatic solvent blend and aromatic hydrocarbons are strong-smelling and carry a long way once they are through an extraction fan.

Underneath the odour sat a second and more significant problem. The old system was catalysed with aromatic isocyanates, which is an exposure question rather than a smell one. The sprayer was using an air-fed mask and was properly protected. Two other members of staff worked in the same area, preparing items and moving trolleys, and they were not. It is a common enough picture in a busy workshop: protection is specified for the person holding the gun and everybody else is treated as a bystander. Where the coating itself is the hazard, that distinction does not hold up.

The Solution

Redwood carried out a full review of the finishing process and recommended switching to the Hesse FANTASTIC and UNA range. Two things changed and they solved different problems. The solvent blend is predominantly butyl acetate rather than an aromatic-heavy mix, which is what dealt with the complaints from next door. And the hardener is aliphatic, with no TDI or MDI in it, which reduced the hazard at source rather than managing it with protective equipment.

The question of who needed protecting was settled separately. Following the change, the client reassessed the risk across the whole spray area rather than only at the gun and revised its control measures so that everybody working in it was covered. What the right level of protection looks like is a decision for each employer’s own COSHH assessment and any two-pack isocyanate system still requires proper extraction and suitable RPE. It is worth stating that a workshop that smells less is not automatically a safer one. Isocyanates are hazardous well below the level at which anyone can detect them, which is why odour is never used as a measure of exposure.

The switch also allowed the process to be streamlined. The two-coat topcoat application was reduced to a single topcoat, bringing the total number of coats down from four to three without any compromise in finish quality. Redwood also made a minor adjustment to the spraying pressure, which reduced overspray and improved efficiency during application.

Implementation was supported with three on-site visits to carry out trials and training with each of the three sprayers individually. Redwood was also present on the day the client made the full changeover, guiding the team through their first complete project on the new system.

The Outcome

The improvements covered safety, efficiency and finish quality across the board.

Aromatic isocyanates removed
Reducing the hazard at source rather than relying on protective equipment to manage it

Odour significantly reduced
A change of solvent blend resolved the complaints from neighbouring businesses

Topcoat coats reduced from two to one
Simplifying the process without affecting quality

Overspray reduced
Following adjustment to spraying pressure

The new system also brought a longer pot life, which had a practical knock-on benefit for day-to-day workflow. With an eight-hour pot life, the team no longer needed to wash out equipment between coats if returning to the same product within a few hours. A quick flush was sufficient. Across a full working week, that reduction in cleaning time translated into more time spent spraying.

The finish quality also saw a marginal improvement. The previous system produced a good result, but the Hesse system delivered an even better one.

Interested in reviewing your finishing process?