PS1 Primer Sealer Stain Block Review

Updated Apr 18, 2024 | Posted Dec 10, 2021 | Product Reviews, Paints | 3 comments

PS1 is a new shellac-based product manufactured by HB42 and sold online. It does everything you’d expect from a shellac-based primer. Touch dry in 15 minutes, re-coat in 45, blocks stains and odours, and you can apply it via brush, roller or sprayer.

It is tintable apparently and it sticks to basically anything. You can only use PS1 primer to spot prime if using it outside because, as with all shellac products, it will not expand and contract with the weather. I’ve been using it since its launch a while ago and thought I’d write a quick PS1 primer sealer stain block review.


An Alternative to Zinsser BIN?


I think everyone reading this review will be familiar with Zinsser BIN. BIN is the brand leader when it comes to shellac primers and a staple in problem solving products for any decorator. We all know how BIN performs, so I think the best thing for me to do is compare it to the PS1 and see how we get on.

The most noticeable difference is PS1 primer is a lot thinner than BIN, making it much easier to apply. This makes an incredible difference when you need to coat whole sections of a ceiling or a wall to block stains, or paint over a varnished wooden door. The difference in viscosity also leads to fewer brush marks and a better finish which is another bonus.


This isn’t to say a coat of PS1 is less capable of blocking a stain because it’s thinner than BIN. I have tested both products side-by-side and they’re both extremely effective when it comes to blocking nasties.

Another difference is the opacity. Most paint is made by scientists in a lab. It would appear PS1 primer is made by wizards who use witchcraft, because even though it is thinner than BIN, the opacity is much better!! It is noticeable when blocking stains and extremely noticeable when coating woodwork!! The timber below has PS1 on the left and Zinsser BIN on the right. As you can see, the PS1 is miles better. I would go as far as to say, using PS1 over BIN would reduce the amount coats of undercoat needed to turn something from light to dark. That is a lot of labour saved!!


Do We Really Need Another Shellac-Based Primer?


PS1 is a new product which is better and easier to use than the current brand leader. If you only intend to use it on small bits, then it probably won’t make a difference which you use. If it’s a big job, then make sure you order the PS1, because you’ll find it miles better. It’s a dream to use, a better finish, better opacity and does all the stuff BIN does. If you do want to try PS1, it is available online.


PS1 Primer Sealer Stain Block Review – by Mike Gregory

PS1 (Primer Sealer Stain Block) Review - a shellac based adhesion primer capable of blocking stains

Updated Apr 18, 2024 | Posted Dec 10, 2021 | 3 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. Mark Jerome

    Thank you very much for this, very helpful.

  2. David Crossman

    It needs to be good given the expense compared with Blockade.

  3. richard

    Decorating direct do FOSSA shellac stainblockers as well as FOSSA coverstain type product both lot cheaper and pretty good, its hard to charge for a little BIN sometimes…

    1l BIN similar price 2.5l FOSSA block and bond in price so a very good saving, merchants should really stock this.


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