Fiddes Full Stop H2O Review

Water-based adhesion primers and stain blocks are common in the decorating industry now However, 10-years ago, when the industry was transitioning towards water-based paint for interior woodwork, finding a good adhesion primer was difficult.

Over the past 10-years, we’ve seen the quality of these primers increase. It isn’t just about grip anymore; a good adhesion primer also needs to be water-based, fast drying, capable of blocking tannins, and suitable for interior or exterior use.

Fiddes Full Stop H2O is a new addition to the market, and as a Professional Decorator, I’ve been putting it through its paces for the past few weeks. I thought it was time to put pen to paper and write a full review.

Product Specifications

• Product Type: Water-based, white acrylic primer–sealer stain blocker and adhesion primer.
• Main Uses: Blocks stains (e.g. water, nicotine, smoke, tannin), seals odours, and resists mould. Adheres to difficult surfaces, creating a base for other paint products.
• Formulation Base: Water/acrylic with low VOC; anti‑mould properties
• Suitable Surfaces: New or previously painted wood, drywall, plaster, existing paint/varnish, aluminium, glass, ceramic tiles, masonry (interior & exterior), oil-based gloss, varnish and woodstain.
• Not Recommended For: Ferrous metals (e.g. steel/iron), external decking, exterior roofing materials, floors.
• Coverage: Up to ~10 m² per litre (depending on substrate density).
• Drying Time: Touch-dry in ~25 minutes; recoat after ~45 minutes (or ~2 hours under low temperature or damp conditions).
• Coats Needed: One to two coats.
• Application Methods: Brush, roller, or spray; easy cleanup with soap and water.
• Compatibility: Accepts oil, water-based, and acrylic topcoats.
• Available from: Next Day Paint. Click here to see online prices.

My Fiddes Full Stop H2O Review

I suppose this is the bit you want to know about; is Fiddes Full Stop a good adhesion primer or stain block?

It flows quite well and gives just enough resistance for you to easily cut a sharp line. The opacity is unbelievable, meaning you often save on topcoats (regardless of whether you’re using satinwood, eggshell, gloss, or emulsion).

The adhesion is fantastic! Not only good, but good after a very short period. A lot of the other adhesion primers I’ve tried take hours, or even days to cure and grip well. Fiddes Full Stop H2O is solid after an hour, and ready for your topcoats.

I’ve tested Fiddes Full Stop H2O extensively as a stain block. It’s well-known that water-based stain blocks aren’t as effective as their oil-based counterparts. That said, they do have their place. They’re faster drying, easier to apply, smell less, and work on about 80% of stains.

Fiddes Full Stop H2O is great on water stains, Sharpie, coffee, red wine, grease, and lipstick after two coats. I tested it alongside a couple of other water-based stain blocks, including Bradite One Can, and the Fiddes is miles better. The only stain it doesn’t block is felt tip, which bleeds straight through within seconds.

So, we’ve established that Fiddes Full Stop H2O is a good adhesion primer and stain block, and that it performs well pretty much as soon as it is touch dry, but what is the downside? Well, there are two; the first is the smell. It isn’t too pongy, but I painted a ceiling with it in an enclosed space a few days ago, and I did notice it.

The other downside is that it warps your brushes while you’re using them. This isn’t the end of the world, but you do need to keep your brush wet, especially on a warm day.

What is Fiddes Full Stop H2O Good for?

Fiddes Full Stop H2O is a great product. It works well as a fast-drying undercoat before applying products like water-based satinwood and gloss.

It also works remarkably well as a stain block over large areas. So, if you have grease on your kitchen walls, you can apply a full coat of Fiddes Full Stop H2O over the lot, wait an hour, then apply your chosen kitchen paint.

It’s perfect for jobs like painting over varnished and stained wood too. The pictures below are of a recent job. Fiddes Full Stop H2O adheres well to the surface, dries quickly, and blocks tannin, so it’s the ideal product. Plus, because the opacity is so good, I’ll only need to apply two coats of satinwood over the top, and it’ll look perfect.

Review Summary

A Shellac-Based Alternative

I still maintain that Fiddes Full Stop H2O is brilliant as a stain block compared to other water-based stain blocks available, but if you’re tasked with blocking a particularly nasty stain, then you will need something a bit stronger.

Full Stop was Fiddes first stain block and adhesion primer, before they launched full Stop H2O. It’s shellac-based, so it’s a lot tougher on stains, and it has better opacity and ease-of-use than most of the other shellac-based primers on the market. We do have a full review, which you can read here. I thought it was worth a mention on this blog so you can choose between the two primers.