White blotches on Red Emulsion wall

[griffbabe]

Hi,

Can anyone answer this?

I painted an interior wall of an outbuilding - a portacabin - in a red colour this last week.
Despite the colder weather it seemed to go off ok, needed a little extra touch up for a solid colour, did that, looked great the over next couple of days.

Past 2 days we've had -4 degrees and in the cabin today its suddenly covered in chalky white blotches.

Can anyone tell me what this is and what I need to do?

Thanks!
J

 

[thermostadt]

Tricky one this Griff,

It could be one of a few things. Without seeing the blotches it’s difficult to say what it is.

Saponification causes chalky, blotches. It’s caused by the minerals in mortar leaching through, but it’s unlikely on the inside wall of a Portacabin.

It’s unlikely to have been nipped by the frost because it doesn’t cause white blotching. Maybe something is wrong with the paint or something on the surface grinning through. It’s a little soon for mould to appear, maybe blooming?

Can you offer more of a description on what the surface was before you painted, what paint you used and what the blotches look like – are they raised and bumpy, can you rub it off with your finger…

 

[joe-90]

Photo needed.

 

[opps]

A stab in the dark but it might well be the result of the cold. Touch dry is possible even below the recommended temperature but the paint won't cure until 5 to 10 degrees.

 

[griffbabe]

Hi,

Just so your not all kept awake at night by this - I think I have fixed it.
Problem was soap left on the roller, I got a damp cloth on the blotches and it foamed up. Cleaned it all off without lifting the paint noticeably.
I had used some fairy liquid when cleaning the rollers previously, I guess I had not rinsed it thoroughly enough.

Doh!