Slow finish drying times - humidity problem

[RogerM]

I've just refurbished my front door, and have finished it with one coat of Sadolin Ultra base coat and 2 coats of Sadolin Ultra Walnut. The can says touch dry in 4 - 6 hours, and re-coatable after 16 hgours, yet 24 hours after applying the top coat, it is still tacky, despite the outside temperature being 22 deg C, and having stirred the product to within an inch of its life.

I phoned the Sadolin technical help line and they told me the problem was caused by high humidity, and that has a far greater effect than temperature. In fact, I was told that a cool dry day (10 - 12 deg C)will produce quicker drying times than a hot (24 - 26 deg C) humid day. With the current high levels of humidity you might want to take this into account before applying a finish in the late afternoon in the expectation that it will be touch dry by nightfall.

I've also experienced the same problem with Sikkens in humid conditions.

 

[Beau]

Pretty standard problem in Devon. Very rarely had any finish drying in the suggested time but I do live on the moors. Opening the door to workshop helps on days like today but then you run the risk of dust blowing in.

 

[RogerM]

Perhaps relative humidity in darkest Devon is higher than the rest of the country.

In fairness to Sadolin, their data sheet does state :-

Touch dry : 4-6 hours.
Recoatable : 16 hours.

Note: Drying times are dependent upon absorption of substrate and drying conditions. At low temperatures and / or conditions of high relative humidity, drying times will be extended.

Whilst Sikkens state no such warning, their data sheet does specify that the drying times quoted are for 20 deg C and relative humidity of 65%. I'd hazard a guess that RH is much higher than that at the moment

 

[ColeyS1]

I use to have issues with most stains drying. Any wood now (even oak) gets wiped with meths first. It's dramatically altered drying times, making them dry more like what the tin states.

Coley

 

[RogerM]

Thanks Coley. This is on new, lightly sanded, marine ply. I must admit I didn't wipe it over with meths first. I'll try that when I come to strip and paint the frame to match.