Crown Trade PX4 Primer Review

Updated May 21, 2024 | Posted Dec 11, 2019 | Product Reviews, Paints | 2 comments

Crown Trade PX4 (Water-based) Is a High-performance all-purpose primer, specifically developed to achieve excellent adhesion, even on tricky surfaces.

PX4 is a water-based, stain-blocking adhesion primer that offers protection from alkaline attack. PX4 also features the added advantage of a quick drying and low-odour finish. This really is an advanced all-purpose primer with excellent adhesion. It blocks stubborn stains, and resists alkaline attack, all in a water-based, quick drying formulation.

Available online by clicking here, you can apply this paint via brush, roller, or airless sprayer. Being an adhesion primer, you wouldn’t use Crown PX4 as a topcoat. It’s more a problem solving product to use on things like melamine, oil-based gloss, or varnish before applying paints like water-based satinwood.

Recoat Time: 1 Hour

Pack Size : 1L, 5L

Touch Dry : 30 minutes

Application : In the past I have used adhesion primers like  Tikkurila Otex Akva, Zinsser Cover stain, and Caparol Half Primer. Both are very good, but unfortunately not available on my doorstep. They also do not have any stain blocking properties. So, I was very keen to try out the new Crown PX4.

I did test it on a water stain on a ceiling and although at first, I thought it hadn’t covered the stain, after emulsion was applied the stain did not penetrate through. This was a fantastic result, because if the Crown PX4 works on something like a water stain, then it will make light work of problems like tannins.


I use a lot of water-based gloss, but I often need an oil-based primer over some surfaces to make absolutely certain stains won’t affect my finished woodwork. Using Crown PX4 means I can stick with water-based products throughout, and still have confidence in the longevity of my work.

I also used PX4 on a few high glossed interior doors and trim. Opacity was as equal as the other named brands and its adhesion was superb.

Cost: These prices are “off the shelf” as I thought that would be only fair to compare. PX4 is just over £20 for a litre and 5 litres £79.99. Zinsser Bullseye 123 plus is exactly the same price, but does not perform to the same level.


My Crown PX4 Review


I really like Crown PX4 and it’s great to see our local suppliers joining our demands for a water-based adhesion primer. More customers are demanding water-based paints nowadays and although the big 3 all sell water-based paints, but only crown have bothered with an adhesion primer.

PX4 is easy to use, fast drying, great opacity, blocks stains well and sticks to basically any surface, It is a massive step up from any other the other adhesion primers I’ve tried. The best thing is, it’s an “off the shelf” product for money Crown Decorating Centre. No more ordering online if you need an adhesion primer which performs at a good level. I’ll be using this product regularly going forward!!

Click here for more information.


Crown Trade PX4 Primer Review - Decorator's forum UK

A fully water-based adhesion primer, designed to deal with difficult surfaces.

Product Brand: Crown Trade

Editor's Rating:


  • Easy to use.
  • Fast drying.
  • Great opacity.
  • Blocks stains.
  • A step up from its competitors.


  • Only available in white.

What Other Decorators Think

PX4 is Crown Trade’s latest adhesion primer and it seems to have done very well since it was launched a couple of years ago. It’s a water-based multipurpose primer and it offers excellent adhesion properties.

It’s purpose built to go on to difficult substrates such as glass, tiles, melamine and non-ferrous metals. It also offers stain blocking capabilities, such as smoke damage, crayons and pen marks, tannings, as well as many others. On top of all this, it withstands alkaline, making it a very versatile product.

Crown Trade px4 comes in two sizes, 1l and 5l. It is only available in white which is a drawback. However, the same is true for most adhesion primers.

I have used Crown px4 on various different substrates including new pre-primed skirting and doors, as well as previously painted surfaces. It has always performed perfectly on each surface. Opacity is ok and it sticks hard and fast to whater you apply it to. The technical information states a 30-minute recoat time on porous surfaces but, under normal circumstances it will be an hour. It flows out well and sands down perfectly.

When using px4 to cover any stains I found it needed to have 2 coats for the product to work correctly. This isn’t too much of an issue as you can apply the second coat as the first one is drying. One advantage is, it’s quick and easy to coat up a full ceiling or wall in Crown PX4, then simply backroll the additional coat. Click here to see online prices.

As far as adhesion goes, I have tested Crown Trade PX4 on various difficult substrates and it out-performs many other water-based adhesion primer.

As a professional decorator, I have no issues at all using this product. I know it’s easy to use, has great adhesion, blocks stains and leaves the perfect surface to be painted over with your finishing product. I would recommend it to anyone. You can buy it online here, or from any Crown Decorating Centre.

Crown PX4 represents a great step forward in terms of paint technology and capability. Take the example of painting over varnished timber: In days gone by, you would have needed a shellac-based primer like Zinsser BIN to offer the adhesion and stain blocking needed for the job. Then, as time went on, we were given oil-based alternatives like Zinsser Cover Stain that do the same job.

What we have with Crown PS4 is a water-based product that does everything Zinsser BIN can do. Except it is cheaper, goes on easier, doesn’t wreck your brushes, is better for the environment and gives a better base. I’m impressed!! Click here to see current prices.

Ryan Fouger

Professional Decorator

Updated May 21, 2024 | Posted Dec 11, 2019 | 2 comments

About the Author

About the Author

Mike Cupit has been in the decorating industry since 2002 and has mostly worked as a Trade Decorator in the domestic sector (peoples’ homes). Self-proclaimed “product geek”, Mike has a passion for paint and decorating tools. Mike now spends most of his time testing paint products and tools, comparing them to similar products on the market, and blogging about the industry in general.


  1. richard

    Spread rate is higher 16m2
    V Zinsser 123plus and Johnstone stainaway thats a good product however it leaves roller marks especially ceilings.

  2. Andrew Everett

    We have tried many different primer undercoats for woodwork such as Aqua undercoat, Fast flow undercoat and none have been that great so we were recommended the PX4 product from The Paint Shed. After coating up the woodwork in a bedroom we quickly realised that the paint was awful as had no opacity, no body and was like vinyl silk! Not quick drying and a nightmare to sand down between coats as it went all rubbery and chewy. Very disappointed with this as had read some good reviews. Took it back to The Paint Shed and exchanged it for Zinsser 123 Bullseye which was night and day compared to the PX4. Will definitely not use this again.


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