What caused this bumpy texture ?

28 Apr 2021
Reaction score
United Kingdom
So I had some MDF skirting and architraves refitted and painted as part of an insurance job and I think they rushed the painting - the skirting and architraves are painted with dulux satinwood in grey, and they have a visible bumpy texture. I think maybe they sprayed an undercoat over everything, not sure. I am planning to use the same grey paint throughout (white gloss had gone horribly yellow) and I am keen to get a nice smooth finish. Any idea what caused this bumpiness and how I can avoid it when painting MDF? I think I’ll be buying primed MDF.


  • BEB1C555-44A8-4C21-8071-64C8A1850555.jpeg
    456 KB · Views: 131
  • 00CEEAB0-5154-4293-9BFB-79C6E2755F7F.jpeg
    176 KB · Views: 126
  • 08A182A2-0468-4105-BA22-408721814AF4.jpeg
    393.9 KB · Views: 123
Sponsored Links
wow thats sh1t complete poop
not sure how they got it that bad
but i am no expert on paint so wait for other comments /??
At a guess I would say it's either
been done with a roller
they didn't let each coat of paint dry properly.
To get a nice finish, use oil-based paint with a good clean brush (once that 'textured' finished is sanded flat).
Sponsored Links
To get a nice finish, use oil-based paint with a good clean brush (once that 'textured' finished is sanded flat).
So if I start with primed MDF, how would I get a nice finish using Dulux satinwood? Its oil based. Do I need an undercoat on the primed mdf? Should I sand between coats?
I would use an oil-based undercoat.

They say satinwood is self undercoating, but I would prefer to use an undercoat first.

Sanding between coats is not essential, but a good idea on areas where any crud, no matter how small, has found it's way onto the paint - this process is known as de-nibbing.

You may need to lightly sand the pre-primed mdf if happens to have a sheen to it, something I have noticed in the past.
I don't think the finished is sprayed. As others have said, it looks like they used a rad roller (very badly).

Pre-primed MDF is normally primed with waterbased paints- they raise the "grain". I you want a super flat finish, you will need to sand them with a fine abrasive (180-240 grit). Unfortunately, the sanding process will cut through the paint at the edges though.

As a a decorator, I prefer to work with un-primed MDF (unless it has been primed with pre-cat spray which doesn't raise the grain). I then apply a coat of Leyland Trade acrylic primer/undercoat. Again, it raises the grain but it is both cheap and very easy to sand flat, easier than the waterbased paints used by timber suppliers. Frankly, I sand most of the paint off until I can see the parallel sanding marks that all mdf has as part of the manufacturing process. See the image below, even though the image is compressed, you should be able to see those parallel lines on the section sanded.


If I were painting the MDF with white oil based eggshell, I would use oil based undercoat to obliterate the dark MDF colour. If it is going to be a darkish colour, I work on the assumption that two coats of oil based eggshell will be fine. The first coat soaks in slightly but when using a decent brand, the second coat provides a uniform sheen.

Decent brushes and paint additives help a lot.

The Purdy Sprig Elite brushes will help you to apply the paint evenly. They don't hold a lot of paint though, so an additive such as a Owatrol oil will help the paint flow as you drag the brush over the surface. Additionally, you can add some terebene to the paint to speed the curing/drying process. You will be using the brush over a number of days- I would recommend buying a BrushMate to store the (£15) brush. It uses a vapour pad to stop the brush drying out. Ordinarily, I only clean my brushes if I accidently drop them on a dusty floor and they become contaminated.

BTW, the links provided might not be the cheapest- they were the first that I stumbled across.

Best of luck.
That finish is what I used to try and achieve when faking stonechip on old cars ;)

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links