CAUTION: Do NOT use Exterior 450 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 or dye bleed-though regardless of priming. All of GF's white paints do NOT require a topcoat. 

NOTE: Exterior 450 Topcoat is not intended for decks. It can be used on tabletops that do not receive direct exposure to sun and rain. As with all fine furniture finishes, wipe up spills in a timely manner to protect the finish.

General Finishes Exterior 450 Topcoat Application Steps

1. Watch product overview video here (2:31 minutes)
2. Work in a well ventilated area.
3. Stir topcoat to reincorporate solids that have settled to the bottom of the can before and throughout the application process. Do not shake. 
4. Test for adhesion when applying over an existing finish. 
5. Thin as desired with distilled water; start with 5%, adding up to 10% by volume. 
6. 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 products non-compliant per SCAQMD Regulations. GF assumes no liability for the improper use of these products.    
7. Apply 2-3 coats of Exterior 450. No more than three coats is recommended. More coats will not improve durability.
   • Hand application: Apply a liberal amount of product using a synthetic bristle brush, foam brush, pad applicator or roller. 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 spray tip size recommendations here. 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. Visit this FAQ for more information on spraying techniques.
8. Finish sand between coats with a 220-320 sanding sponge to improve smoothness and adhesion. Do not use steel wool.
9. Remove dust with a vacuum, compressed air, an oil-free tack cloth or a water-dampened rag.

NOTE: Exterior 450 is designed to let the water permeate the finish; as it dries, the water releases back out to allow the finish to tighten down again. Temporary cloudiness may occur as the finish dries. The UV additive in 450 Clear will protect the integrity of the finish, but will not prevent the wood from changing color from sunlight.

WARNING: We do not recommend Exterior 450 stains or topcoats for exotic woods, ipe, teak or other dense, oily woods. 

Warning: Do not use water-based products with Linseed Oils or Danish Oils.

Dry Time