Outdoor paint temperatures?

[Brockport Bill 1,668]

seasons changing -- what's the bottom temperature for outdoor temperatures to do rattle can paint? the cans typically say for "best results" and suggest 50 or 55 degrees as lowest temp? What have the experiences been for rattle spray cans in the real world doing tractor projects -- not trying to achive show quality perfection, or factory look, but just a decent quality result? thanks

[Jeff-C175 7,202]

3 hours ago, Brockport Bill said:

bottom temperature

 

I could twist that around, but not gonna go there!

 

I've painted down as low as about 40° but that was bringing the items out from a warmer area, painting them, and returning them to a warmer area.  By 'warmer' I mean about 60°F.  They came out fine.

 

I'm not sure what happens if the items are cold, painted cold, and remain cold.  One thing seems certain, it would take longer to dry.

 

I just painted a garage door, yeah, not rattle can but exterior latex, and that can said 40°F to 90°F.  Of course, this means nothing at all in the context of your post, but it did surprise me a bit when I read that.

It topped out at about 71°F here today at the 'shaw'.  Gawjuss day!  Raining and windy now though, and temps dropping again.

 

Edited November 19, 2021 by Jeff-C175

[ebinmaine 67,675]

 

We have - on many occasions - stored and/or prepped parts in the basement workshop, brought them outside to be painted, then immediately back in the basement to dry and cure. 

 

We find that a perfectly fine job with Rust-Oleum 2X can be done above roughly 35 exterior temperature. 

Trina's sprayed at colder temps too. 

Of course the parts are warm being brought out. They're immediately returned to the warm basement. 

 

We use a bunch of metal coat hangers or several particular boards to paint on. The coat hangers are handy because the parts can be transported, painted, and dried all without contact.  

 

 

[ri702bill 8,350]

I do the same, We have an old cast iron radiator in the basement with a support beam above - I hang the smaller parts there once painted to dry in the colder weather. My coat hanger hooks see double duty - have used them for years to hang disc brake calipers while duing automotive repairs.

Bill

[953 nut 55,325]

2 hours ago, ebinmaine said:

Of course the parts are warm being brought out. They're immediately returned to the warm basement.

The whole idea of not painting below the required temperature is to allow the solvents to escape. if the parts and paint are warm when the process begins and ends the temperature where they come together is no big deal. The dry time will be faster with low humidity so a winter heated space is ideal. The cure time may be longer if the parts are not kept in a warm area so be patient.

[ebinmaine 67,675]

17 minutes ago, 953 nut said:

The whole idea of not painting below the required temperature is to allow the solvents to escape. if the parts and paint are warm when the process begins and ends the temperature where they come together is no big deal. The dry time will be faster with low humidity so a winter heated space is ideal. The cure time may be longer if the parts are not kept in a warm area so be patient.

 

Agreed for the most part.

I phrase it that way because we find that if she tries to paint below about 20° give or take, the nozzle of the can actually freezes up fairly quickly.

 

[Goldnboy 927]

My best painting seems to occur in the low 40-50's low humidity, no bugs (or they are moving to slow), and no wrinkles in paint. 

[Jeff-C175 7,202]

58 minutes ago, ebinmaine said:

nozzle of the can actually freezes up fairly quickly.

 

Not to mention the frost bitten finger tip!

[ri702bill 8,350]

One trick I use in the cooler weather is one I used in my old building model cars days as a kid. Stand your rattle cans upright in a saucepan filled with hot tap water. It quickly heats the paint (and raises the internal pressure too). Warm parts, warm paint and move them inside. Remember to towel dry the paint cans before use!!!

Bill

[Brockport Bill 1,668]

great info from everyone - sorta what i hoped and was thinking -- could i keep the parts and paint inside -- then take the parts outside and then quickly bring the painted parts back indoors? My only wonder was...... does the sprayed paint get "chilled" while airborne causing an adhesion or other problems? great insights !!!!!!!!!!

[ebinmaine 67,675]

39 minutes ago, Brockport Bill said:

great info from everyone - sorta what i hoped and was thinking -- could i keep the parts and paint inside -- then take the parts outside and then quickly bring the painted parts back indoors? My only wonder was...... does the sprayed paint get "chilled" while airborne causing an adhesion or other problems? great insights !!!!!!!!!!

 

We haven't seen that until down around 15 or 20 degrees.  

 

 

But it's pretty much always warmer than that during the day.  

[953 nut 55,325]

10 hours ago, ebinmaine said:

below about 20° give or take, the nozzle of the can actually freezes up fairly quickly

That would probably be the propellant in the can having a change of phase from gas to solid as its pressure drops at such low temperatures.

[ebinmaine 67,675]

Just now, 953 nut said:

That would probably be the propellant in the can having a change of phase from gas to solid as its pressure drops at such low temperatures.

Ahhh yes. That makes sense. 

[kpinnc 12,111]

Not to mention pressure in the rattle can drops with temperature.

 

I've painted below freezing, but as already been said- the parts and paint were indoors and only outside long enough to spray. Like 5 minutes...

[Zeek 2,286]

On 11/19/2021 at 4:30 AM, ebinmaine said:

 

We have - on many occasions - stored and/or prepped parts in the basement workshop, brought them outside to be painted, then immediately back in the basement to dry and cure. 

 

We find that a perfectly fine job with Rust-Oleum 2X can be done above roughly 35 exterior temperature. 

Trina's sprayed at colder temps too. 

Of course the parts are warm being brought out. They're immediately returned to the warm basement. 

 

We use a bunch of metal coat hangers or several particular boards to paint on. The coat hangers are handy because the parts can be transported, painted, and dried all without contact.  

 

 

I did this as well for small parts as long as it wasn't below 50°. I took the warm part and rattle-can outside, sprayed and brought the can back inside until the next coat. When done, I brought the part inside in the warm to dry. I never had any issue. I used coat hangers as well. Humidity level is also a factor. If it is too high, the paint can get cloudy if you leave the part outside and don't bring it in where it's dry and warm.

[Jeff-C175 7,202]

I learned last night that it's not a good idea to try and accelerate the drying time by using a heat gun ( at a distance! ).  What started as a beautiful glossy finish ended up as a wrinkled mess.  It's only a brake drum though, nobody but me will ever see it!  And it's still protected from rusting again... well, at least the painted part anyway!