Before you spray
Surface preparation & sanding
Build a cleaner finish through substrate inspection, staged sanding, dust control, and between-coat preparation.
The final coat magnifies the quality of everything beneath it. A repeatable preparation sequence is the foundation of clarity, adhesion, and an even sheen.
Prepare the substrate
Inspect moisture, contamination, glue residue, machining marks, and defects before coating. Sand with the grain and progress through grits without skipping so the next step removes the previous scratch pattern.
Clean between steps
Remove dust from profiles, pores, edges, and corners. Keep compressed air clean and dry, and avoid contaminating a prepared surface with bare hands or shop residue.
Sand the coating as specified
Sealers and intermediate coats need the correct cure and abrasive. Sanding too early can load the paper and tear the film; sanding too aggressively can cut through edges and alter color.
Keep learning
Related Renner guides
Why Renner is green
How water-based technology, lower emissions, and responsible manufacturing support a cleaner finishing process.
Read the labelUnderstand Renner product codes
Decode the letters and numbers used to identify lacquers, topcoats, stains, catalysts, additives, and colorants.
2K systemsCatalysts, hardeners & mixing
Understand mix ratios, pot life, and why the specified catalyst is part of the coating system.