High-volume, low-pressure (HVLP) spraying sits between aerosols and a dedicated coating machine. It lets you coat large or awkwardly shaped pieces, such as stretched canvases with wrapped edges, without the limits of a roller. It also asks more of you: the equipment has to be set up for the coating you are using, the spraying area has to be suitable, and the operator needs practice before working on customer prints.
Is spraying right for your work?
Spraying suits workshops that coat a steady mix of sizes and formats and have, or can create, a properly ventilated spray area. It is less suitable where space is shared with other work or where you cannot control dust and overspray. For small, occasional jobs an aerosol such as ClearJet is often simpler; for regular flat work, a coating machine usually gives more repeatable results. Our guide to aerosol coatings covers the lighter-duty option.
Before you start
Read the coating’s technical data sheet and safety data sheet (SDS) first. They tell you whether the product is suitable for spray application, whether thinning is permitted, and what the correct cleaning solvent is. Do not guess at thinning ratios or settings. If the data sheet does not cover spraying, ask Landor before you try it.
Solvent coatings release vapour, and spraying turns liquid into a fine mist. Spray only in a well-ventilated area designed for the purpose, away from ignition sources, with the respiratory and other PPE the SDS specifies. Base the arrangements on your own risk assessment, and check that your spray equipment is suitable for use with solvent-based products.
A basic spraying routine
- Confirm the print is fully dry and has outgassed. Coating too early traps solvent and moisture under the film.
- Prepare the coating as the data sheet directs and strain it if recommended, to remove any particles that could block the nozzle.
- Set the gun up following the equipment manufacturer’s instructions, then adjust it on scrap card or a printed offcut until the fan pattern is even with no spitting.
- Position the print upright or flat, as suits the piece, with clear space around it so you can start and finish each pass off the edge.
- Keep the gun square to the surface and move your whole arm at a steady speed rather than flicking from the wrist.
- Trigger before you reach the print and release after you pass it, overlapping each pass consistently.
- Apply light coats rather than one heavy one. Allow each coat to dry as described on the data sheet before applying the next.
- Leave the piece to dry in a clean, ventilated area and clean the equipment straight away with the recommended solvent.
Reading the finish
Runs and sags usually mean too much material in one place: speed up or reduce the flow. A dry, sandy texture often means the spray is drying before it lands, so the gun may be too far away or the coating too thin. Striping points to uneven overlap. Our coating defects guide covers these in more detail.
Remember that solvent coatings do not suit every ink and substrate. Spray a test piece on the same media and ink as the job, let it dry fully and check it before committing to the full print.
If you are deciding between spraying, rolling and a machine, the Landor team can talk it through with you. Ring 01252 624 411 or send us a message through the contact page.