Exterior Paint and Application Temperature

I am looking to repaint part of the exterior of my house, specifically the wooden trim around windows and the garage. The trim was previously painted around 5 years ago, began flaking recently, has been cleaned and sanded and spot primed in areas where bare wood was present. I live in Canada and outside temperatures are becoming a bit of an issue. I understand that paint manufacturers typically recommend that paint be applied when the temperature is above 10°C (50°F). Our daytime temperature does reach around 12 to 14°C (54 to 57°F) for around 4 to 6 hours and then plummets quickly. Nightime lows are still above freezing.

The paint I will use is alkyd based and it states 4 to 6 hours drying time. Is applying the paint above 10°C and then a few hours later the temperature dropping below (but not below freezing) a major issue or will it ruin the job?

 

As long as the air and wood temps are above 50` when you apply the paint, it should be ok for adhering well. Cold/cool temps will slow down the drying process of oil base paint. The biggest problem you might encounter is the dew laying on the not quite dry paint and affecting the gloss.

There is a paint additive for sale at most paint stores that will speed up the drying time of oil base paints - japan drier. It must be used sparingly! read the label. If you add too much it will hurt both the life and looks of the paint.

 

Will the curing of the paint not be adversely affected, i.e. starting to cure for a few hours and then slowing down as the temperature drops below 50°. Will the paint continue to cure the next day as temperatures rise again?

Thanks for your help

 

While I try not to do much exterior painting in those types of conditions, sometimes there is no choice I've never expeirenced any problems with oil base paint and cold nights other than if the dew sets on it before it gets dry to the touch it will often flatten the sheen. Applying 2 thinner coats of paint may also help - just make sure the 1st coat is good and dry before applying the 2nd.

Basically the cold temps just slows or delays the drying.

 

Well I did the first coat and it is at least dry to the touch. We've now just started to get frosts overnight so I think I'll wait to second coat next year. Will be better than a frost ruining my hard work.

Only problem I've noticed with the first coat is it's actually got quite a satin sheen to it. The previous paint is very much a flatter looking finish, almost matt but not quite.

The only paint I had in a tin from the previous house owners had congealed and so I had to paint with new paint. The DIY store colour "matched" from some large paint flakes I gave them and selected what they said was the same paint base as before - Data Sheet for new paint "219" (based on the tin the old paint was in - Data Sheet for old paint "215"). The old tin didn't have any labels to show what colour was inside. I contacted the paint manufacturer and they said that both the 215 and 219 paints were identicial (if that's the case then why label them differently?).

So I wonder if it's the cold weather that has made the new paint shinier, or if the new paint base I was given is actually glossier than the old paint, or if the quality control at Sico is such that the gloss level varies significantly. Any thoughts would be appreciated as I would like to do the second coat next year with a paint that better matches the rest of the house?

Thanks again

 

I don't think I've ever used any Sico coatings. I thought you were using an oil base paint as opposed to stain. All modern day exterior oil paints have a gloss but stains tend to be flat. A stain may have a bit of sheen when first applied but it should lose the sheen as it cures. Cool temps slow down the drying and cure time.

The 219 may be a reformulated version of the 215. Good paint manufactures will constantly be looking for ways of improving their coatings. Also ingrediants may from time to time become unavailable or a better substitue used instead.

I agree that waiting for spring to apply the 2nd coat is a good idea. 1 coat should protect the wood fine thru the winter. it will also give you time to find out if the sheen does infact deaden.

 

I find the description of the Sico product as an opaque stain to be very peculiar as it does not in fact stain the wood!! It looks like a paint and goes on like a paint (although I must admit it is much thinner than paints I have used). Where the old "paint" had flaked off there was bare wood underneath that had clearly not absorbed any colour from the so-called stain. I'm sure there must be something in the formulation that differentiates it as a stain but it seems to act more like a paint. It is alkyd based which I believe is similar to oil based paint/stain.

Anyway, many thanks for all your replies - they have helped me immensely.

Thank You.

 

Alkyld is basically a fancy way of saying oil base

Solid stains are kind of in between a paint and a stain. They color like a paint does but doesn't have as heavy a film and will let the wood grain texture show. Semi-transparent stains color the wood and also allow the different colors and grains to show.

Generally a solid stain doesn't require a primer and solid stain seldom peels, which makes for less prep when it's time to repaint/stain. Normally you don't want to apply solid stain over paint. It is best used over raw or previously stained wood. I have used solid stain on old houses where the majority of the paint has been removed. A solid stain because it has a thinner film doesn't give as much protection as paint does. While stain seldom peels if it is applied over paint - those areas can peel in the future.