Crown PX3 & PX4 Primer Review

Updated May 21, 2024 | Posted Dec 28, 2019 | Product Reviews, Paints | 6 comments

First off, thanks to Crown for asking me to review their products, this time it is a PX3 and PX4 primer review.

These are trade quality adhesion primers, meaning you wouldn’t use them as a finish coat, but as a “first coat” for problem surfaces such as melamine, varnish, or even oil-based gloss paint.

Both products are very similar, which is why I thought I’d cover both in one review. Crown PX4 is a water-based adhesion primer, PX3 is the oil-based version. You’d normally expect an oil-based primer to perform better and have the added advantage of being a stain block, but take a lot longer to dry. You can buy both of these products online by clicking here.

I’ve had the opportunity to use them a couple times, and every time I think “no, this won’t work directly on to this surface”, it always surprises me at how well they actually grip!!

First run out was on water-based polythene varnish that’s had 8 years to cure. I only gave the skirting boards a rub down with 150 grit sponge denibber, half the room I applied the water-based version (PX4) and the other half in the solvent based version (PX3).


The first comment I have is I know this is a grip/bridging primer, so it’s not a high opacity primer. I did think the solvent based would have more opacity than it does, but I’ve been a water-based paint user for about 5 to 6 years, so maybe I’m remembering solvent-based paints from back in the good old days.

I left the surface an hour and gave it a light scratch test with my thumb nail and it didn’t budge. I gave it proper scratch test the next day, and even using the sharks fin on my Olfa Knife it didn’t budge at all!

The next outing was on a bathroom where the old guy had used Dulux trade oil based eggshell on wallpaper in 1976!! The wallpaper was blown vinyl so couldn’t give it a good sand, I did a test patch with PX4 and it gripped perfectly this video is after 20 minutes, straight on without denibbing the surface.


This is, in my opinion, a very impressive grip primer, I’ve got some melamine kitchen cabinet doors to spray and it’s definitely going to my primer for that job, I do try to stick to water based so haven’t given the solvent version a run out yet but I’m more than happy to say I’d definitely trust it do it exactly what it says on the tin.

Click here to see online prices.


Crown PX3 & PX4 Primer Review - Decorator's forum UK

Adhesion primers, one water-based and one oil-based. Both designed to stick to problem surfaces and create the perfect base for topcoats.

Product Brand: Crown Trade

Editor's Rating:


  • Good opacity.
  • Excellent grip!
  • Easy to use.
  • Blocks stains.


  • None that I have noticed, but I've only been using them for a few weeks. They genuinely seem better than other adhesion primers.

Updated May 21, 2024 | Posted Dec 28, 2019 | 6 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. Rach Coulson

    How did the px4 do on melamine mate, I’ve used the px3 oil based on glass and find it Brill after the scratch test. I’m usually a zinsser user but could easily switch

  2. Peter J. Nealey

    I used px4 to paint the cabinets and got a very good answer. I got the idea for this from Karanadecor official website.

  3. Trish Johnston

    Can I use PX4 as an undercoat on copper piping on the radiator please?

  4. Ashling

    Hi there, I used this on wood, three of my walls were fine. It turned out clear on them but the fourth wall it started turning white and was really thick.
    Any idea what happened there?

  5. David Black

    Water has leaked from my kitchen into my lounge. The leak has been fixed and I need a primer to cover the stains on the wall but it must be able to breathe! I do not want to seal in the dampness. Please advise at your earliest convenience.
    Thank you, David

  6. David Black

    Water has leaked from my kitchen through to my lounge. The leak has been fixed but the wall is stained. I need a primer which allows the wall to breathe. Can you help please?


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