Ancient Preservation to Modern Manufacturing: the Brush and Flow Coating Process

For thousands of years, craftsmen have faced a common challenge: how to protect wood from the damaging effects of weather, moisture, sunlight, and time.

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The earliest documented wood preservation methods date to around 5000 BC, when the ancient Greeks applied olive oil to wooden structures and temple components to enhance their appearance and improve durability. The process was simple: coat the wood, allow it to absorb the oils, and brush away any excess.

Centuries later, the Norse and Vikings employed a remarkably similar technique when preparing timber for their ships. Wooden planks were soaked in protective oils and then brushed to evenly distribute the coating while removing any excess. This helped to improve the longevity of seafaring vessels that endured some of the harshest environments on earth.

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While technology has advanced dramatically since those early days, the underlying principle remains unchanged: apply a coating, allow it to penetrate the wood, and distribute it evenly for maximum protection.

The Brush and Flow coater is a specialized machine designed to apply stains, sealers, protectives, and other wood coatings quickly, consistently, and efficiently.

Unlike spray systems that atomize coating material, a flow coater floods or “flows” coating directly onto the surface of the wood. Excess material is then recovered and recirculated, making the process highly efficient while ensuring complete coverage of complex wood profiles.

Image of Stanza SBC Brush and Flow Coating Machine serving as a link to the product page on the website

Because the coating is allowed to flow over the entire surface before being brushed into the wood grain, the process is particularly effective for:

  • Siding
  • Decking
  • Timbers
  • Fence Boards
  • Trim and Moulding Products
  • Rough Sawn Lumber
  • Textured Wood Profiles

In many regions around the world, flow coaters are commonly referred to as impregnation 1machines because of their ability to help coatings penetrate deeply into the wood surface.

  1. Impregnated wood is defined as wood that has undergone a process where low molecular weight resin is infused into its cell walls, resulting in the formation of an insoluble polymer that enhances its density, moisture resistance, and mechanical strength. ↩︎

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The Brush and Flow Coating Process

The process begins when a wood plank or timber is loaded onto the machine’s conveyor system.

The SBC-300 utilizes a high-speed steel roller conveyor driven by an inverter-controlled motor system. This allows operators to precisely adjust production speeds to match coating requirements and production demands.

As the board travels through the machine, it remains securely guided for consistent processing.

Once inside the machine, the wood passes through a 360-degree pipe and nozzle arrangement.

A diaphragm pump delivers coating material to the nozzles, which flow the coating over the entire surface of the board. Rather than applying a thin surface layer, the system floods the material to ensure complete coverage.

At this stage, the coating begins to penetrate the fibers and absorb into the structure of the wood grain.

After coating application, the board passes through a series of air knives.

These high-velocity streams of air remove excess coating from the surface while directing the unused material back into the machine trough.

The recovered coating is filtered and recirculated back to the application system, where it can be reused. This significantly improves transfer efficiency and minimizes material waste.

Following the air knife blow-off, the board enters the brushing station. Horizontal and vertical brushes work in unison to distribute the coating evenly across the surface. These brushes aid in:

  • Pushing coating deeper into the wood’s grain
  • Reaching textured and rough-hewn surfaces
  • Coating grooves, cracks, and crevices
  • Improving coating uniformity and coverage
  • Enhancing the overall appearance of the finished product

This brushing action is one of the key advantages of the brush and flow coating process, especially when trying to achieve a consistent finish on irregular surfaces.

As the coated board exits the machine, pneumatic load rollers clamp and guide the material to maintain stability and safety.

The finished piece then leaves the machine ready for drying, curing, or other finishing steps.


Is this Method Right for Me?

The flow and brush coating process has become a preferred solution for many wood product manufacturers because it offers several significant advantages.

Since the coating flows over the entire workpiece before brushing, even complex profiles and textured surfaces receive consistent treatment.

A single machine can apply a wide variety of coating materials, including:

  • Water-based coatings
  • Solvent-based coatings
  • Stains
  • Sealers
  • Preservatives
  • Topcoats

This flexibility allows manufacturers to process a diverse range of products without needing to invest in multiple coating systems.

The recirculation system captures excess coating and returns it to the application process, helping to reduce waste and improve efficiency.

Flow coaters are relatively simple to configure and operate, allowing manufacturers to move between varying products and coating types with minimal downtime.

By combining controlled application with mechanical brushing, manufacturers achieve repeatable results between items, maintaining quality standards across production runs.

Today’s manufacturing environments demand higher production rates and tighter quality control than ever before, but the underlying principles of wood preservation remain surprisingly familiar.

Modern brush and flow coating takes this ancient practice and transforms it into a highly efficient and production ready solution for today’s wood manufacturers.

Whether you’re producing siding, decking, timbers, or specialty wood products, our Brush and Flow Coating systems provide effective penetration, coverage, efficiency, and consistency that has withstood the test of time.


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