Johnstones trade aqua water based stain brilliant white going yellow

[Jaypb]

Hi I have been painting all the wood work in my house with this afternoon previously using Dulux once which had gone really yellow. I have been sanding the surface to provide a key and had no issues applying the paint. However I have noticed on one window ledge which was painted about 3-4 months ago it has started yellowing, the curious thing is it has only occured underneath some porcelain ornaments my wife has on the window ledge.

Does anyone have any idea why this would have happened or what can be done to prevent it?

Thanks for any help

 

[accelerator]

It's either a chemical reaction with the porcelain, or it is the pressure of the porcelain on the paint that is making it degrade.

Either way, putting the porcelain on a mat would probably help.

 

[JohnD]

This is a well-known event.

Sunlight bleaches out the paint and prevents it from yellowing.

You say the yellowing only happens under ornaments....

...which cover the paint and prevent Sunlight getting to it.

Move the ornaments each time you dust the windowsill.