Painting, at what temp?

[NMDemDist2]

We are painting my work (or getting ready to anyway) and the paint says not to paint if it's below 50 degrees. it's a cinderblock building with lots of drafts but a heater that will keep it in the 60s

any reason we can't paint ?? it's damp as all get out outside and cold, but the little heater should be enough eh?

[oneshooter]

1. Not really.

Air temp inside is not as important as the temp of the wall surface. If it is below 55deg then the paint will not dry properly and will be prone to peeling.

[jeff47]

2. To solve the above-mentioned problem,

To solve the above-mentioned problem, you can heat the space for a few days first to get the wall warm. Then it should be good for paint.

If you have one, a handheld IR thermometer will give you the temperature of the wall. They look like this: http://www.amazon.com/GSI-Professional-Non-Contact-High-Temperature-Thermometer/dp/B004HMI1IA

[NMDemDist2]

3. hmmmm, the walls are probably warmer than that

and we do leave the heater on overnight at 65

i think i'll wait til we get some sunshine and the humidity goes below 100%

but thanks, that answer did help!

[pipoman]

4. Are you painting cinder block?

Will you be using a primer or sealer? I have never painted cinder block, but would guess choosing a primer or sealer suited to concrete would be a good idea. The mortar is alkaline and the surface humidity could be higher if the outside is very cold and the inside is being heated. I don't know, but I would research before painting. We rented a house years ago which had painted basement walls. The paint was peeling and bubbling, short of sand blasting and sealing the concrete I don't think repainting would have lasted either. My thought would be that once painted you're stuck with it...much harder to keep up over years if the first paint treatment doesn't have good adhesion.

[NMDemDist2]

5. yes, but it's a repaint situation

most of it's been painted before and the same problem, cracking peeling paint

we're gonna prime it then paint with Sherwin Williams but it's been too darn cold!

[pipoman]

6. The Sherwin Williams people should know..

and I am no expert in house paint. I do know a bit about automotive finishes. If there is a an adhesion problem with the paint on a car, it cannot be fixed for the long term without sanding below the layer of finish which isn't adhering. If you paint over the existing paint, the new finish is only adhered as well as the base coat. I don't know if non-automotive primers/paints have the same properties? If I were going to paint the old basement in my rental house, someone would have to give me a reasonable explanation for why one product or another would be stable over a base which I knew was not stable...there certainly could be a product or explanation, without one I would have probably rented a blaster and removed as much of the old surface as possible, then treated the base surface with a product or procedure which would enhance adhesion..

With automotive finishes, which admittedly are much more complex, everything effects the adhesion and/or finish quality...temperature, humidity, barometric pressure, air quality, ventilation, etc. There are procedures, products and formulations available for almost any conditions which mitigate the chances of an undesirable result.

[TheMadMonk]

7. Too cold and the paint counterintuitively dries too fast.

Gloss especially. It can go tacky in 3-4 strokes of the brush.