Valspar Trade Knot Block is a fully water-based acrylic primer/undercoat which has been developed with stain blocking capabilities, including knot bleed. Touch dry in 30 minutes, but the recoat time is roughly 2 – 4 hours (depending on conditions). Knot Block is only available in white and costs roughly £30 for 2.5L at B&Q.
My Valspar Trade Knot Block Review
Valspar Trade Knot Block is very quick and easy to use. It flies on, and brush marks just melt away. You’ll find opacity lacking somewhat, but you should always apply two coats of this paint for it to work to the best of its abilities anyway.
I’m a bit of a decorating geek, and love developments in paint technology! At the time of writing this review, Valspar Trade have just launched a redeveloped range of paint, and they’ve really gone to town. The first on the list is Valspar Trade Knot Block, which is advertised as an acrylic undercoat. This is a massive understatement on Valspar Trade’s part, and I’ll tell you why;
Yes, you can use Knot Block as an acrylic primer/undercoat and it will perform better than most other products of its type. Not only does it prime timber, but as stated in the opening paragraph, it also stops sap from knots from bleeding through.
It doesn’t stop there though. Valspar Trade Knot Block has very good adhesion qualities, meaning you can use it as a primer over old oil-based coatings before using a water-based topcoats. I have tested it a few times, and it has always been solid.
Moreover, because Valspar Trade Knot Block is more than capable of holding back stains such as tannins, it is the perfect product for priming previously stained or varnished timber. It works too! We’re talking about a fully water-based product that flies on, sticks like sh1t to stained woodwork, is fast drying, blocks all stains, blocks knots, and leaves the perfect base for your topcoats.
The last thing you can use Knot Block for is blocking stains on plastered walls and ceiling (even though it isn’t advertised as such). Be it mould growth, permanent pen, or even water damage. You do need to stick to the two-coat-rule, but it works well. Again, it is quick and easy to apply, dries nice and fast, and is more than capable of holding back just about any stain.
This is a brand-new product, but it’s going to be very popular amongst decorators. I think Valspar Trade tried to develop some sort of upgraded primer/undercoat, and inadvertently came up with something which has multiple uses. Valspar Trade Knot Block is like nothing I’ve ever used. To perform as well as it does, and still be so quick and easy to use is a masterpiece in my honest opinion. I can’t wait to start seeing the feedback from other decorators.
Valspar Trade Knot Block Review – by Mike Cupit