Haymes Ultrahold, the stain blocker and when you need one
Why the stain comes back
You paint over the mark, it looks perfect while it's wet, and a couple of days later there's a faint brown shadow sitting exactly where the mark used to be. That's not bad paint and it isn't your rolling, it's the stain itself dissolving into the fresh coat and travelling up through it, and putting another topcoat on top will only feed the same process again.
Water damage does it, smoke does it, and tannin out of timber does it worse than anything, so a knot in a skirting board will keep bleeding through white paint for years if nothing stops it.
What a stain blocking prepcoat does differently
A stain blocker isn't there to help the topcoat stick, even though it does that too. Its actual job is to sit between the stain and the paint as a barrier the stain can't dissolve into, so whatever is underneath stays underneath.
That's why you can't substitute an ordinary undercoat here. An undercoat evens out the surface and gives the topcoat something to bite into, and a water based one will happily let a tannin through, because nothing in it was designed to stop that happening.
Haymes Ultrahold is the one we keep for this. It's a prepcoat rather than a topcoat, so it goes on first and gets painted over, and it's the thing to reach for when the surface has a history.
When you actually need it
Reach for a stain blocker when there's a visible water mark on a ceiling, when you're painting over timber that's likely to bleed, when the room has been smoked in, or when you've already painted over something once and watched it come back. That last one is the clearest signal you'll get.
You don't need it on sound plasterboard that's never been marked, and there's no point spending the money to prime a clean wall you're just recolouring.
Doing it properly
Clean the surface first, because a stain blocker can't bond through grease or dust any better than paint can. Sand back anything flaking, then spot prime the marked areas or do the whole surface if the staining is widespread.
Check the tin for the recoat time and stick to it rather than guessing, because going over it too early is how you drag the barrier into the topcoat and undo the whole point of it.
One more thing worth saying plainly, because it gets asked a lot: we mix and tint paint to order in the shop from the range we stock, and what you pick comes out of the Haymes colour range rather than being read off something you bring in.
Shop related products
- Uni-Pro High Tech Microfibre Cover 180mm. A 10mm nap for walls and ceilings.
- Uni-Pro Unifiber 270mm Roller Cover 6 Pack. Worth it if the job is a whole room.
- Paint Brush Utility 100mm Synthetic. For cutting in around the marked patches.
- Uni-Pro 5-in-1 Caulk Tool. Handy for scraping back the flaky bits.
There's more in our paint and accessories collection, and the mixing service is on the Haymes paint trade centre page.
Did you know we keep Haymes Ultrahold prepcoat in the shop in 1 litre and 4 litre, and it isn't listed online. Give us a ring on (08) 8536 4333 to check what is on the shelf.
Read next
- How to choose a roller sleeve for your paint finish
- How to avoid paint drips and streaks while painting
- How to prep your painting tools before you start
Prep is the part I still want to skip every single time, and it's the part that decides whether the job looks any good.
Candeece
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