cold weather: cold-drying paint / cold-curing curing coatings?

[Opcom]

What kind of primer/zinc primer, and satin or flat paint (or coating), suitable for use on a steel 19" rack, will dry 'normally' in temperatures around 40 degrees?

Done a little rack-repainting, but here it is winter, and there's a rack with some surface rust that needs some wire wheel work, then priming over the bare metal, a few existing rusty spots that can't be reached with a wheel or brush.  - and then get a coat of paint.

The surface rust isn't too bad and there's plenty of original paint left. last time I had this kind of thing, it was summer, and I gave the rusty areas a good cleaning with a wire wheel, then sprayed Zinc paint over the entire thing including small rust pits, then after that was dry sprayed/brushed on the coat of paint of the right color.

What to do in 40 degree weather?

I have to paint outside, but can move the rack into the work shop to dry/cure - but it'll be down to 40 degrees in there as well.

I could put an oil-filled convection space heater in the rack, but that seems an uncertain remedy. I'm open to suggestions!

[KA3EKH]

I have used a propane salamander heater to warm up the garage before and had no bad effects, just remember not to paint while the heater is on! Did whole cars that way in the winter.
Why do you suppose they call those heaters “Salamanders” anyway?

[Opcom]

There are restarant cookers called salamanders. They are a kind of broiler but as for that naming it doesn't add clarity to the propane heater's name.

My work area at this time is way too small to be lighting a fire like that.

[K8DI]

Do you have 240 in your space?

I do, so I got an $85 5kW electric heater off Amazon. It’s junky but it works. I cut the plug off and put on an L13-30, which happens to be what’s on my RCA and all my PA system racks. I had originally put the L14-30 in the garage space to test said racks, so it was an easy choice. Although the heater isn’t great, there’s no fire and it is plenty to go from 35 to 65 in an hour. If you go this route, open it up and oil the motor…China must’ve been running low when mine was built.

https://www.amazon.com/gp/aw/d/B003XOZN7A/ref=yo_ii_img?ie=UTF8&psc=1

Ed

[KD1SH]

 A reference to a mythical fire-loving creature of the same name, I think.

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Why do you suppose they call those heaters “Salamanders” anyway?

[Opcom]

I guess the first order is to remove as much rust and flaked paint as possible then sand any rough areas before priming and painting.

Already bought a 3-pack of wire wheel set for the drill and a set of abrasive flap discs 10 each 40-60-80-120 grit for the angle grinder (easy does it there). Also a pack of 3M respirators for particulate dust. That will be enough.

A show car finish is not required, just decently flat and rust-stopping. Thinking of zinc primer but could make do with flat black primer or header paint maybe. Just have to research.

The thing I'm thinking about is fumes from it drying in the closed shop. Likely rattle cans will be used.

An alternative would be to prepare it then pay for electrostatic paining but no idea what that costs.

[KD1SH]

  I'm not any sort of paint expert, but a few thoughts, anyway:
  I doubt you'll find any rattle-can paint that will dry properly at 40 degrees, or any brush-on paint, for that matter. But, I have painted cabinets and enclosures outside at that temperature. I just get everything all prepared outside in advance—painting table, saw-horses, whatever—but keep the rattle-can, and the parts to be painted, inside where it's warmer, until ready. Then, quickly bring them outside and shoot them before the metal cools, and bring them right back into my warmer basement to dry. By warmer, I mean low 60's. A portable halogen lamp keeps them nice and toasty while drying. With a halogen lamp, or several of them, you could probably dry paint just fine in your 40 degree shop; those lamps will keep the metal—especially if the paint is black—well up into the 80's or above.
  As far as fumes and odors from drying paint, my wife is extremely sensitive to things like that, and  our hot-air ducting tends to bring stuff like that upstairs, but it's never been a problem. She'll sometimes notice a very slight odor and ask me what it is, but it never bothers her. Shooting that rattle-can down  in my shop would be a problem, but drying paint is fine.
  I try to be proactive and get all my painting tasks accomplished before the temperature drops, but, procrastination, best-laid-plans, all that...

[Opcom]

I agree with warmer weather for painting and doing it outside if at all possible!

The shop can be warmed up to 60 I think without much trouble, if it's not a cold spell here.

[KD1SH]

  If my basement were bigger I'd think of making myself a small ventilated paint-booth, with a forced-air exhaust to the outside, but then the blower would create a negative pressure differential with respect to the outside, and quite likely pull my oil-burner and propane water-heater flue gasses back down the chimney. The cure for that would be to install an inlet vent to the outside, to allow fresh air to replace the air that my blower discharged and thus equalize the pressure differential, but then, in the winter months, that incoming air would be cold, so I'd have to heat that incoming air, bringing me back, essentially, to where I started; still needing to heat things.