In our paint store a common problem we hear is trouble with applying water based paints over old oil based coatings. So we have enlisted the help of Oisin Butler Painting & Decorating Specialists to share their advice for how to apply water based paint.
how to apply water based paint
How to apply water based paint is a question that keeps popping up these days, most of all, water based gloss or satinwood for woodwork. We mostly used oil based paint on our woodwork and these days this trend is switching to water based paint. Applying oil based paint isn’t the same as applying water based paint and this is leading to problems for lots of D.I.Y painters. The heart of the problem people are having is when they apply water based paint over oil based paint. There’s a tendency for the paint to just peel away in no time at all! Why does this happen I hear you ask? Its simple really, its all about the preparation.
This is the preparation that’s mostly used.
- Sand down the old paint surface.
- Dust off the surface.
- Apply undercoat.
- Apply topcoat.
Thats it, fairly straightforward. The problem is, this wont work when you apply water based paint over oil based paint.
Oil based paint can be used as a stain blocking substitute. When repainting a door with oil based paint it can be like you are applying a stain block. Whether you know it or not, all grime on your door will be sealed and blocked by your oil based paint.
Water based paint is great in general but its rubbish when it comes to stain blocking. All dirt or grime on your door, frame etc needs to be removed as the first step in preparation. I use Krud Kutter for this, its and excellent degreaser. Once the woodwork has been scrubbed clean you can move onto sanding. The main point of sanding the old gloss paint, on your door for example, is to remove the sheen so the new paint can bond to the surface. The next step is to apply a water based primer, Zinsser 1-2-3 is perfect for this. You need this primer to grip onto the old oil based paint, it provides a good sound surface for your water based satinwood or gloss. Finally you just apply water based paint, satinwood or gloss, to get the finish you want.
New steps for preparation.
- Clean down the surface with sugar soap or Krud Kutter.
- Sand down the surface to remove the sheen.
- Apply a coat of Zinsser 1-2-3 primer.
- Apply 2 coats of your chosen water based satinwood or gloss.
If you follow these new steps from start to finish then you will get a long lasting finish from your water based paint. If you use the old steps when applying your water based paint then it won’t be long until its chipping and peeling away…
Hope you found this useful, Oisin.