The Best Adhesion Primer on the Market

Adhesion primers seem to be a big “thing” at the moment on the Decorators Forum UK – OK, maybe not as big as spraying and/or masking, but there do seem to be a lot of them about, whereas a few years ago your choice was basically Zinsser Bullseye 1-2-3. My feeling is that this is driven by other changes in our market. For example, it’s now relatively straightforward to spray furniture or kitchen cabinets to give them a new lease of life, but you want to make sure the paint sticks.

Water-based paints for…no, I won’t say “trim” in case I offend someone…woodwork are clearly here to stay, whether you love them or loathe them, but they don’t always stick to any surface, and often an adhesion primer is the solution. So we need more adhesion primers because of other changes in our industry, and the manufacturers have been only too pleased to oblige!

But are they all the same? I thought I’d put a few to the test and see how they compare and see if I can find the best adhesion primer on the market. Obviously, I haven’t tested every product, and apologies if I didn’t include your favourite. Haft primer from Caparol was one I really did want to include as I know a lot of forum members rave about it, but it was very hard to get hold of during lockdown, so I’m afraid I haven’t included it (but would love to give it a go at some point in the future). So which ones did I test?

I tried all the primers on a number of different surfaces, allowed them to dry/cure thoroughly, and then attempted to scrape them off with a teaspoon. The only exception is that I ran out of Whitsons (and again, because of lockdown, wasn’t able to get any more), so I replaced it on some surfaces with Zinsser B-I-N, as I was interested to see how it would perform.

The surfaces I primed were:

· Wooden doors previously coated (about 10 years ago) with oil-based gloss

o Keyed

o Not keyed

· Melamine

o Keyed

o Not keyed

· Wooden plank treated with two coats of Sadolin wood stain

o Keyed

o Not keyed

· Wooden plank treated with two coats of Ronseal Yacht Varnish

o Keyed

o Not keyed

Here are the Adhesion Primer Test Results

When the surface was keyed, all the primers performed significantly better; I’d give both Crown products, Whitsons and Zinsser All-Coat 10 out of 10, but the other two (Otex Akva and Bullseye 1-2-3) still weren’t perfect, a small amount of the primer did scratch off in my test

Wood Treated with Ronseal Yacht Varnish

Sadly by this stage of the testing I had run out of Whitsons, which is a primer I really like. So I wasn’t able to include it in the latter stages of the test. I should say though, that I have in the past used it on both stained and varnished wood, and it stuck really well, so as an adhesion primer I’m confident using it on these surfaces. What it didn’t do – and in fairness, it never claimed to do – was to block stains, so it did allow the brown of the woodstain to bleed back through when I used it. Therefore, to avoid using a separate stain block, you might want to use one of the “all-in-one” stain-blocking adhesion primers that I used during this test.

Interestingly, on the Zinsser app (if you don’t have this, it’s free to download and is a handy guide to what primers they recommend on which surfaces) they recommend B-I-N on stained or varnished wood (for interior use), so I replaced the Bullseye with its cousin, and also dropped Otex Akva out of the test, so the four products tested were Zinsser B-I-N, Zinsser AllCoat, Crown PX3 and Crown PX4 (all of which also have stain-blocking properties in addition to adhesion properties). Could one of these be the best adhesion primer on the market? The results of this part of the test were really easy to report: all four passed with flying colours, regardless of whether the varnished surface was keyed or not. Again, I’d probably play safe in a customer’s house and give the surface a key anyway, but in this small test it didn’t appear to make any difference.

Wood Treated with Sadolin Wood Stain

Again, for this part of the test I had run out of Whitsons, so the four products tested were Zinsser B-I-N, Zinsser AllCoat, Crown PX3 and Crown PX4.

As with the varnished wood, all four adhered really well, regardless of whether or not the surface was keyed.

The only difference between the primers was not in their adhesion properties, but their opacity. In the photo (right), the darker sections of the plank are the two Crown products (PX3 and PX4), and the whiter sections (i.e. the products with the better opacity) were the two Zinsser ones (B-I-N and AllCoat). So they all did an equally good job in terms of adhesion, but going down the Zinsser route if you’re painting over dark woodstain or varnish might save you a coat of paint…

Summary – So what is the best Adhesion Primer on the Market?

Most of the primers I tested did a decent job. I have to say, I was put off Zinsser 1-2-3 Bullseye, and Tikkurila Otex Akva to some extent as they performed less well than the others on melamine specifically in this test, and to be honest, if you can find one primer that will work brilliantly on all surfaces, surely that keeps life simple?! So for now I’ll ignore those two, and concentrate on the ones that performed consistently well in my test:

So that leaves us with five:

· Whitsons, which has fantastic grip qualities and which I will definitely continue to use (as soon as lockdown is over and I can get my hands on some more!). Its only downside is that, unlike the others, it doesn’t block stains, so if you’re painting over something that might bleed back through, it’s probably safest to go with one of the others. But I love it anyway, it sticks like glue and has really good opacity.

· Zinsser B-I-N, which let’s be honest you’re going to have in your van anyway. I didn’t test it on oil-based gloss or on melamine, but it did really well on varnish and woodstain. It’s hard to review in a way, as everyone already knows it and there has been so much written about it online, I don’t think there’s anything I can add! Available online here.

· Crown PX3 (for those who can’t remember, this is the solvent-based one). This is a bit of an anomaly. It did absolutely everything it said on the tin, adhesion was great and it stopped the woodstain bleeding through. Overall, it was probably marginally the best of the bunch in terms of adhesion. But I don’t like it! Sorry Crown – I love you really, the guys at my local CDC will kill me, but I don’t like this product. Maybe it’s just me, but I found:

o It settles out and takes a lot of stirring to get it back to something usable (and then it promptly settles out again!)

o The solvent smell is really strong and not pleasant!

o It takes a long time to dry on some surfaces – it says 4-6 hours, but was less on the woodstain, and significantly more on the melamine

o It is very thin (maybe it needed even more stirring!), so it drips badly and has poor opacity

o I couldn’t get my brush clean after using it, had to throw it away in the end (good job I used an old one!) Available online here.

· Crown PX4, on the other hand, I like! It’s got a nice consistency, grips well, smells decent and while it doesn’t have the best opacity in the world, it seems to be fine on lighter colours, it was only an issue on the dark woodstain. And being water-based, it dries really quickly on any surface. Of the water-based primers, Whitsons has better opacity, but this has the added stain-blocking benefit. Available online here.

· Zinsser AllCoat Multi-Surface Primer and Finish (Solvent-Based). Sorry to spell it out in long-hand, but Zinsser do so many products called AllCoat, and I didn’t want to confuse anyone! Interestingly, it’s not primarily marketed as a grip primer – it’s positioned as a “primer and finish in one”, and my only previous experience of using it was in that way, in a small office previously inhabited by a heavy smoker, and it did a great job blocking the nicotine. But the legendary Mark Neil put me onto the idea of using it as a primer-undercoat under Helmi 80 (Tikkurila’s water-based gloss), and you know, I think he may be onto something! Comparing it to PX3, it doesn’t settle out in the tin, the solvent smell is nothing like as strong or unpleasant, it dries faster, has better opacity and doesn’t kill your brushes. But don’t limit it to just brush application – if you look on Zinsser’s web site, they’re really pushing how well this stuff sprays. The opacity is a nice bonus if you’re painting over the top with water-based satin, for example, as many of these paints can be a bit thin. Available online here.

Final Thoughts

Basically any of these five will do a good job adhesion-wise. Whitsons is great but doesn’t offer a stain-block capability, but in many situations that’s not an issue. Personally I didn’t get on with PX3, but I know other people who do. For me, the one that did the best of all worlds (adhesion, stain-blocking, opacity, speed of drying, not killing your brush) was the Zinsser AllCoat. If you want a water-based product, it’s a choice between the high opacity but no stain-blocking Whitsons, or the lower opacity stain-blocking Crown PX4.

Hope that helps!