Winner of Fine Woodworking's "Best Overall Choice Award," High Performance Topcoat was voted as the hardest, most durable consumer polyurethane topcoat. It is so versatile, it can be brushed or sprayed.
CAUTION: Do NOT use GF High Performance or any other clear coat, over white or light paints such as GF Milk Paint, or GF White Poly as it may cause yellowing. Any clear coat can become reactive over wood substrates or existing finishes causing tannin, stain or dye bleed-through. All of GF's White Paints, brushable or spray versions, do NOT require a topcoat.
General Finishes High Performance Water Based Topcoat Application Steps for Raw Wood & Sealed Surface
- Watch the High Performance Product Overview Video Here (2:07)
- Work in a well-ventilated area.
- Stir thoroughly to reincorporate solids that have settled to the bottom of the can before and throughout the application process.
- Test for adhesion.
- Thin as desired with distilled water; start with 5%, adding up to 10% by volume.
- Increase open time, if needed, with 10-15% General Finishes Extender if allowed by local regulations. GF Extender will improve flow and leveling and increase open time, which is helpful in dry climates. California Residents: Adding more than 2% of GF Extender will make the product
snon-compliant per SCAQMD Regulations. GF assumes no liability for the improper use of these products.
- Apply 2-3 coats of High Performance. More coats will not improve durability.If a faster build is desired over raw wood, use General Finishes Sanding Sealer for the first coat, followed by 2 coats of High Performance Topcoat.
- Hand application: Apply a liberal amount of product using a synthetic bristle brush, foam brush, pad applicator, staining pad or roller such as Whizz or AllPro Velour brand. Avoid pressure and excessive back brushing. Brush along the wood grain using smooth, even strokes with light lap marks. Let lap marks dry - they WILL tighten down.
- Spray application: Before spraying, strain topcoat through a fine-mesh filter. Spray wet films at 3-5-mil thickness. HVLP: 1.1mm-1.3mm spray tip, medium air cap. Verify tip sizes with your equipment supplier. See our general guide for spray tip sizes. Keep your gun at a 90° angle, 6-8" from the surface. On large, flat areas, use wet, even patterns 6-8" wide. For narrow surfaces, reduce the fan pattern to 2-3" wide to reduce overspray. Overlap each pass 25% to conceal lines. Wear a full filter respirator (NIOSH/MSHA-approved) and work in a ventilated space. Read here for more information on spraying techniques.
- Face frames and drawers on cabinets: High Performance can be successfully applied by hand to cabinet face frames or edges with a brush, pad or small, cabinet-specific roller such as Whizz or AllPro Velour brand.
- Finish sand between coats with a fine-grade (220-320) foam sanding pad to improve smoothness and adhesion. Do not use steel wool.
- Remove dust with a vacuum, compressed air, an oil-free tack cloth or a water-dampened rag.
Tips to prevent streaking during hand-application:
See our video: How to Prevent Streaking with Water Based Topcoat
- Use a semi-gloss or gloss sheen with little to no flatting agents. The more flatting agents, the more likely a topcoat will streak when applied.
- To avoid streaking with the flatter sheens, apply a liberal amount of product and avoid using pressure and back-brushing. Wipe along the wood grain using smooth, even strokes. For large surfaces, apply topcoat with a large applicator, such as a paint pad.
- Remove any streaks that occur by buffing with fine-grade (220-320) sanding pad, or sanding well and re-coating.
- For the smoothest result, apply with a spray gun.
You mix can High Performance Topcoat sheens to adjust your sheen. For example, you can mix High Performance Flat and High Performance Gloss to obtain a different sheen.
Warning: Do not use water-based products with Linseed Oils or Danish Oils.