Exterior 450 by General Finishes

4.8/5 · 4 reviews
from $56.95
Free Delivery
Quebec, Ontario · More info

Exterior 450 from General Finishes is a waterbased clear exterior varnish designed for vertical exterior wood applications. Exterior 450 provides a tough, protective finish for your wood that will withstand the rigors of the sun, rain, snow, and wind. Fortified with UV absorbers to help minimize fading and maximize performance, it is ideal for outdoor furniture, doors and case goods. Exterior 450 from General Finishes has built-in mildewcide, which retards mold, mildew, and fungus growth.

Exterior 450 is available in a variety of sheens. It flows well and dries rapidly to a clear finish. It is flexible and tough, and will resist the expansion and contraction of the wood through hot and cold weather that typically causes cracking and peeling.

How to use


Oil based stains must be completely dry before using a waterbased top coat. Wait a minimum of 48 hours before applying this product.

On raw wood, sand with the grain using #120 and finishing with #220 grit paper. On stained wood, sanding with #320 or finer paper or buffing with a buffing pad is optional. Do not sand through the stain.


  • Stir Well prior to use.
  • Using a foam brush or paint brush, apply liberally using smooth, even strokes going with the grain. Use enough material to provide a wet film. Do not over brush. Apply and move on.
  • Sand between coats using #320-#400 grit paper or extra fine to super fine sanding pads. Remove dust before recoating.


High Performance Poly can be applied via brush or spray.
- Brush: Use a quality foam brush or paint pad applicator.

  • Spray gun: Exterior 450 can be applied with Compressed air, HVLP, Air-Assisted Airless & Airless guns. Check your equipment supplier for proper tip sizes.

Allow 1 –2 hours between coats before sanding (temperature / humidity dependent). Sand between coats with 220 micron or # 320 grit paper or finer. 3 - 5 coats recommended.

Drying time: Dry time is normally 2-4 hours under ideal conditions (70°F or 21°C, 70% humidity). Cooler temperatures and higher humidity will prolong drying time up to 8-10 hours.

Number of coats: A minimum of 3 coats is recommended. Additional coats may be applied to increase durability and depth


946 ml · Flat $56.95 In stock
946 ml · Gloss $56.95 In stock
946 ml · Satin $56.95 In stock
946 ml · Semi-gloss $56.95 Out of stock
3.78 L · Flat $128.95 In stock
3.78 L · Gloss $128.95 In stock
3.78 L · Satin $128.95 In stock
3.78 L · Semi-gloss $128.95 In stock


Classification Wood Varnishes
Brand General Finishes
  • 946 ml
  • 3.78 L
Sold Since March 26, 2014

140-160 sq ft / L


< 123 g / L




Can be diluted with 10-20% water if needed.


1 year minimum, protect from freezing. Do not use the product if it has frozen.

Tools cleaning

Warm soapy water


Can be applied on almost any waterbased or solvent based stain or paint. Test compatibility prior to beginning projec


Flat, Satin, Semi-Gloss and Gloss

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First time trying this finish will use again

Robert Ledingham · Jun 27, 2023

Sprayed well, robust clear finish. Standing up well, looks good.

Holding up wonderfully!

Ryan Storkson · Mar 20, 2021

Happy to use this again.

Used the Exterior 450 for a pine table top that would live year round on out patio. Was concerned that the weather may take its toll on it. It’s been a full summer and winter and it still looks just as good as when we finished it. I’m impressed and glad the previous reviews I had read turned out to be true.

Quick Service

Paul Lamothe · Mar 21, 2020

Initially the product was not available for the quantity I needed. I received an immediate response to my enquiry as to when it would be available. The best.....received another email advising when Exterior 450 was in. .

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