Can White Paint lose strength?

[django47]

A couple of months ago I put up coving in the front room. I was well pleased with the out come, especially after I painted it (white). Even now looking at it, it's impossible to see the joins, either corner ones or the flat ones. the paint has totally hidden the joins. After I finished I put the pot which must have been 2/3 full in the garden shed.
Anyway I decided to do the bedroom with what I had left, only needed to buy one strip. It went up okay but the problem is, after I filled in the joins and corners, then sanded it down, it was nice and smooth but when I tried to paint it to hide the joins, it didn't hide the joins at all. you can see every join and the filler. What I don't understand is I used the same paint as before, which I would bet anyone £20 to point out the joins.Its a 'vinyl matt' interior white which I bought in Tesco (diy department).
It was in the shed for about 6 weeks or so and the weather has not been cold. Also the lid was well fastened down, in fact when I opened it I was surprised to find that it had no skin on the surface. I gave it a good stir before using it
I am really puzzled why this paint has changed in some way. Could the paint have thinned out somehow, having been opened once before then left to stand(with lid tightly shut).

 

[Growler]

Stick a picture up .

These good lads will figure it out.

 

[dcdec]

It could be the angle at which the light hits it. Also its important to prime the filler with thinned emulsion to stop it from flashing.
When filling coving joins always spread the filler right out across the joint, say around six inches each side. This allows you to rub down and feather it nicely to avoid any lumps or bumps.
Regarding the paint it generally lasts ok if stored properly as you seem to have done, i didn't know tesco sold paint! Wont be long before we'll be able to get a hair cut, a massage and a ..... ahem, is there no end to their domination? I'd have more faith in a branded trade paint, surely they don't do their own brand??


Just to add, coving is a lot easier to fill in this fashion with a powder filler like easifill

 

[django47]

It could be the angle at which the light hits it. Also its important to prime the filler with thinned emulsion to stop it from flashing.
When filling coving joins always spread the filler right out across the joint, say around six inches each side. This allows you to rub down and feather it nicely to avoid any lumps or bumps.
Regarding the paint it generally lasts ok if stored properly as you seem to have done, i didn't know tesco sold paint! Wont be long before we'll be able to get a hair cut, a massage and a ..... ahem, is there no end to their domination? I'd have more faith in a branded trade paint, surely they don't do their own brand??

I typed a long reply to your post but it vanished from my screen before I had quite finished. I hope that somehow you received it as I'm a slow typist and couldn't do it all again. so annoying!!!


Just to add, coving is a lot easier to fill in this fashion with a powder filler like easifill