Shellac Based Primer Review

Shellac based primers are made up of resin acids, esters with glycerol and ethanol and are some of the best primers you can get when dealing with surfaces that have been heavily stained by nicotine, oils or water. They’re also equally effective at sealing sap and bleeding knots in timber. Shellac based primers are essentially perfect for interior use but can also be used to spot-prime exterior surfaces.

With that being said, we thought we’d take a look at some of the most popular shellac primers being used in the painting and decorating industry today and review them based on categories such as stain blocking, adhesion and overall effectiveness.

Zinsser BIN Shellac Based Primer Review

Let’s start off with what is possibly the most popular shellac-based primers currently available in the UK. I’m talking about Zinsser BIN of course. The BIN primer is used for adhesion/stain blocking and is exceptionally good when other paints struggle to adhere to a surface.

Extraordinarily, Zinsser BIN Shellac Based Primer was first developed way back in 1946 and whilst there’s been plenty of tweaks to the formula over the years, in 2021 it’s still standing the test of time.

Perhaps the most influential reason that painters and decorators across the UK use Zinsser BIN is its ability to not only completely cover stains but also ensure the stains never come through again.

Good examples of this are heavy damp stains and notoriously hideous nicotine stains which can easily be covered up when using Zinsser BIN.

Furthermore, the adhesion of this shellac-based primer is top-notch and thus easily sticks to internal surfaces such as plaster and softwoods/hardwoods. You should bear in mind that for more porous surfaces such as softwood, the primer will be absorbed more so you may need to be more vigorous in your application.

Otherwise, it’s perfect for use on any internal surface you consider to be a problem area and will give the next coat in your paint system a fantastic binding medium on which to adhere to.

My preferred application method for this (and all shellac based primers) would be using a cheap brush that can be thrown away as quite frankly, the cleanup process is difficult. However, if you’re spot priming knots on objects such as spindles, Zinsser BIN does come in an aerosol can which is quick and effective.

Overall, Zinsser BIN is probably the best shellac based primer out there so it’s no surprise that painters always have some readily available in their vans.

Coo-Var Shellac Primer All Review

Next up on our list is Coo-Var Shellac Primer which is newer to the market but has gained a foothold amongst decorators as their go-to shellac-based primer. And whilst it’s not exactly perfect, there’s very little to separate it from Zinsser BIN in my opinion.

Just like BIN, you can use this primer to prime surfaces where paint adhesion is sub-optimal (think painting over sealants for example) which basically means the paint is far less likely to crack or flake.

It’s also highly recommended for spot priming and sealing knots on exterior wood. Here’s an example of how I used Coo-Var’s Shellac Primer to treat failed knots on the exterior of a front door:

before and after sealing knots

I also found that this primer is incredibly quick to dry (around 15 minutes or so, although Coo-Var suggests 30 minutes before applying the next coat in your paint system) and a bit more scratch-resistant than other primers.

Overall, the Coo-Var Shellac-Based Primer is on par with Zinsser BIN and yet is slightly cheaper.

Smith and Roger Blockade Review

Like Zinsser BIN and Coo-Var, Smith and Roger’s Blockade primer is perfect for blocking and sealer stains, knots and odours and works on anything from plaster and drywall to woods and metals.

Whilst Zinsser BIN is the most popular choice, Smith and Roger Blockade tends to have a more loyal following with decorators across the UK swearing by its quality and suggesting that it outperforms both BIN and Coo-Var. I’ve tried this primer on a couple of occasions and would say that there’s no real difference between the 3.

Armed with this information, you might be wondering why more decorators don’t use it, especially as it’s the cheapest of the 3. Simply put, it’s just not stocked in as many places so is harder to get hold of. If you are interested in trying it, you can pick some up at Crown Decorating Centres, most Leyland stores and from the Paint Shed.

Final Thoughts

Shellac Based Primers are some of the best primers you can get, especially for blocking stains and providing substrates with the perfect amount of adhesion for paint systems. Whilst you’re better off using water-based systems like Zinsser 123 for plaster, shellac-based primers are certainly worth the investment if you need to prime woods and metals.

In terms of the 3 main producers of shellac-based primers, there’s really not that much to separate them except for the price. And even then, unless you’re buying in very large quantities the price difference is negligible.

In my opinion, I wouldn’t have a strong preference and would actually recommend any of the 3. For professional decorators, the likes of Zinsser BIN will be the easiest to get hold of at trade centres whereas, for the average DIYer, I’d recommend Coo-Var simply based on the fact that it’s ever so slightly easier to work with than the other two.

I hope you found these reviews helpful and feel free to browse the rest of our site for some more information about different paints and primers.