Temperature of metal for paint spraying

[Surveyor]

As a novice on the restoration of vehicles and ancillary equipment, I have decided to sand blast and spray paint myself, 

This is a stupid question but I have read a lot and there seems to be a different opinion on the minimum temperature of the surface to be sprayed and how long this temperature should be maintained. 

If we were looking at brick laying it's 4 degrees on a falling thermometer and 2 on a rising one, I am hoping something similar for spray painting, 

The tin of paint I have does not give an answer. 

[ruxy]

It is years since I was involved with this , the most important is checking the  "dew-point' and keeping a few safe degrees above on ambient temperature.   To be honest - there is a bit more to it , such as aluminium is a colder metal than such as steel  , remember how aluminium windows & doors created condensation on the inside , then the makers split the extrusions and re-bonded them to create a thermal break.  A bit better but then along came uPVC.     You are risking disaster painting at low temperatures.  BLOOM is also a danger , whatever the colour you could end up with matt  powdery white clouds ,  obviously some types of paint are more resistant than others.

[terryb]

don't paint at 6 degrees or less. If its damp don't paint. Alway try to paint under cover, and be wary of diesel space heaters as they throw out particles which will contaminate your paint.

sprayed some items last night, prepped them first, hung on the radiator to warm through, then out into the workshop, a light 'mist' coat. wait 'till touch dry, then a nice even full coat. Once touch dry, back indoors hung to go off overnight.Even touch dry if you leave them out it can bloom (milky dull finish) and probably be running in condensation!  

[Tomo.T]

Best thing for painting anything at this time of year is infra red lamps. They heat the object not the air so do not circulate dust. They will disperse moisture and quickly raise the temperature of the substrate....... and keep you warm as well !

[Surveyor]

Many thanks for the answers, i suspected this would be the case, I am looking for a garage so i can paint the beast and also keep it warm

[Pete Ashby]

The three replies you've got pretty well sum it up.

In the UK unless you are working in a well insulated and heated workshop metal prep and painting of any sort is best left until the dew point and ambient temperature rises in the spring.

Pete

[Rootes75]

Some very sensible advice. I have always been told not less than 10 degrees and definately not when there is damp in the air.

 

[Scammell4199]

I try not to paint below 10 degrees. I have found high teens to be a sweet spot. Until recently i was always under the impression, that the hotter the better. It was a very hot day last summer and i sprayed the winch for our scammell and it looked ok to begin with, but when i went back the following day it had dried more matt than normally. I quizzed the vintage car painters in the unit next door to mine and he said it can be too hot, and they hold their booth at, i think, it was 20 odd degrees. He said the thinner was partially evaporating before the paint reached the surface. Since then i have stuck to applying final top coat in the mid to high teens and always had good results. Maybe no need to be quite so fussy when it comes to primer. 

Have you done any spraying before? I have taught myself over the years, and i now like to think i can do a nice finish.

Good luck, Richard

[Surveyor]

1 hour ago, Scammell4199 said:

I try not to paint below 10 degrees. I have found high teens to be a sweet spot. Until recently i was always under the impression, that the hotter the better. It was a very hot day last summer and i sprayed the winch for our scammell and it looked ok to begin with, but when i went back the following day it had dried more matt than normally. I quizzed the vintage car painters in the unit next door to mine and he said it can be too hot, and they hold their booth at, i think, it was 20 odd degrees. He said the thinner was partially evaporating before the paint reached the surface. Since then i have stuck to applying final top coat in the mid to high teens and always had good results. Maybe no need to be quite so fussy when it comes to primer. 

Have you done any spraying before? I have taught myself over the years, and i now like to think i can do a nice finish.

Good luck, Richard

Thanks, I have a rear Land rover door to practice on, have sprayed small items but i want to try my hand with it, also if its doesent look like a paint shop finish i think it will look okay as some members on here have when in the forces even painted over dirt