General Finishes Exterior 450 Water Based Topcoat, 1 Quart, Flat

In a front entry door application (white oak), I’m quite pleased with the results obtained with this GF Exterior 450 product. However, its application requires a bit more “technique” than other topcoat poly/urethane products produced by GF. Specifically, in brush applications the product goes on more like a shellac, rather than a typical water-based topcoat. That is, the product sets up so fast that it does not tolerate a lot of brush strokes (rework) over a newly wetted area. So, as with shellac, you want to avoid overloading your brush, then brush (wet) an area, and then keep the wetted area moving (expanding) by stroking subsequent brush loads into the previously wetted area. Don’t try to level brush strokes that appear in the wet product, as it self-levels beautifully upon drying. Also, if you see areas that appear cloudy white (likely due to too heavy of a coat) leave them alone, as they will dry clear. As well, even if you do mess up an area, in just a 2 – 3 hours it can be lightly sanded and easily recoated. Not to wear out the shellac analogy, but using a good quality medium soft nylon or natural bristle brush is essential for applying this fast-setting topcoat product. In retrospect, if you can use a HVLP spray outfit that’s likely a better choice over a brush application. For reference, I applied the product in near ideal ambient conditions (low humidity / <80F). All applied coats were thinned 8 - 10 percent with water. I did five light coats on the in-place door sanding out lightly (320 grit) only after coats 2 and 3. On bare white oak grain raising was minimal, and final results, in satin, produced a soft pleasing sheen with a rich honey oak appearance similar to an oil-based product. Exterior durability of a water-based product is an open question, but all GF products, in my experience, are of superior quality. So, I’ll take the leap that 450’s performance will be comparable to a good quality exterior varnish.

This replaces other exterior poly-spar varnishes I've found. For 15 years, my place (a block from the Atlantic ocean and its salt air) always cracked oil based polyurethane finishes (the names sold in home centers). Tried this 450 product 5 years ago on my pine porch ceilings and mahogany railings. It was a pleasure to apply (it dries in less than an hour and thus I could get in 3-4 coats in a day). Probably near twice the price of some brands, but no question it's worth it when I don't have to recoat every six months anymore. No cracks in the finish by the next season - just beautiful wood. Recoat every two years and wood will last a very long time - no replacing railings and ceilings every 10 years. As most latex/water based coating products, it moves with the wood much better than oil poly. As the label says it will take more coats than a traditional polyurethane to get the build up that can protect wood well. If you share the opinion that painting isn't fun, nor turpentine paint cleanup or finish mess, you will find the soap-water cleanup nice. No I don't work for the company - I have just found that Mother Nature tells the truth as to what works outside - alot of other famous name products' tv advertising just does not hold up near water. It's an excellent product and the best solution to outdoor wood.

I refinished a front door after stripping and sanding three layers of tough and ugly paint. I had never tackled such a project before and I know I oversanded a few areas. I used General Finishes Chestnut stain which went on very well. This topcoat put the finishing touch on. I put 3 coats on and the result was a beautiful satin sheen on the door. I am so pleased. I would definitely use General Finishes products again. I used the remaining topcoat product to put a finish on an old coffee box shipping container. The topcoat brought out the wood grain and it looks nice enough to have in my kitchen. Definitely a quality product.

Always the best , general finishes!!

Did not apply as smooth as the flat out flat or flat of semi in the regular poly, but finish is more durable

I use this over General Finishes exterior stain on fiberglass doors. It’s a great product that is easy to apply and holds up very well. I am a professional painter who appreciates quality products and this clear coat does not disappoint.

I use this with my hvlp and it works great. Goes on nice and dries better than brushing. I will sand between coats with fine steel wool or 1000 grit or higher. Comes our smooth.

Worked great. Very carefully packaged. Nice product