Pimples in oil paint

[Need Help21]

Fellow DIYers

My missus has just painted a door and she has done an ace job.

Prior to painting we invested in some Purdy brushes (which were free from dust and grit) and painted in a dust free room. Primer and undercoat were applied and allowed to dry. The finish on them was spotless and without pimples.

Two top coats were applied from a new tin of Dulux professional gloss. Upon drying I have noticed that there lots of pimples all over the door. She had advised that she may have shook the can of top coat prior to application. She did say that if any it was only a quick shake

Can anyone advise what may have caused the pimples??? I am leaning towards tiny air bubbles. I presume the paint should have been slowly stired and not shaken

Thanks





Need Help21

 

[Robbie uk]

Some times you get pimple type bubbles if you have glossed a door with a roller, this will introduce air into the paint. There is a possibility that the paint was not stirred enough, but its better to shake the tin as vigorously as you can, bit like the machines that do it fro you in the shop. If it is not stirred enough and the paint had been stood for a while the oils in the paint can raise to the top of the tin, and this is what you are brushing on. There could be a slight possibility of some form of grease on the door which wasn't seen prior to painting.

 

[Growler]

Need Help21:
You don't mention what kind of primer/undercoat your wife has used, so...................................................................................................................

What kind of primer/undercoat has your wife used ?

 

[Need Help21]

The primer was dulux wood and metal oil based white primer and the undercoat is dulux oil based professional undercoat. I am getting ideas that perhaps it is dust put up into the air following sanding prior to paint application and then slowly settling

 

[Need Help21]

I did forget to mention that the door has been removed from the frame and is being painted horizontally. I am beginning to think the pimples are actually dust. Is it unheard of to paint a door horizontally or is it best done in the frame?

 

[carl27]

hello did you use a brush on the top coat or a gloss roller becuase gloss rollers leave tiny air bubbles in the paints so i roll them use just drag my brush down the door to get the bubbles out. carl