I would like to paint my front door. It is a metal door. What kind of paint should I use and where should I buy it? Is the correct way to paint it? Help

If you live where moisture growing on paint outdoors is common because of the high humidity, or where the paint "chaulks" because of the intense sunlight, then I'd use an exterior oil based paint if it's still available in your area.

Otherwise, I'd use an interior oil based paint cuz you probably don't need the additives (like mildewcides and zinc oxide as the white pigment to prevent excessive chaulking.

If it wuz me, I would go to either:
Color Wheel Paints,
Frazee Paints
Kwal Paints
Parker Paints
or, if you live in Canada, General Paint.

All of those chain stores are part of the Comex Group which is a paint manufacturer headquartered in Mexico.

At any of the above named stores, I'd ask whether or not to use Envirogard or Monamel.

Envirogard is a latex paint, but it uses an acrylic binder resin that cross links so densely that it cures to about the same durability as an oil based paint.

Monamel is a "hybrid" paint. It consists of oil based binder resins suspended in water. So, what evaporates from the paint as it dries is water, but what's left behind on the door is the same thing as if you'd painted with an oil based paint.

I really don't know if Envirogard and Monamel come in exterior versions so that you can get them with mildewcides and UV blockers as well. It's worth it to ask.

Monamel is dry to the touch just as quickly as a latex paint, but it does take a good two weeks or so for it to form a HARD film. During the first few days, you'll be able to scrape it off your door with your fingernail.

PS:
The reason why there are interior and exterior oil based paints is because wood swells and shrinks with changes in it's moisture content cause by seasonal changes in temperature and humidity. Consequently, exterior oil based paints won't cross link as densely so that they can retain sufficient elasticity to stretch and shrink with the wood.

Both interior and exterior latex paints are more than elastic enough to accomodate the dimensional changes in wood, and so the primary difference between interior and exterior latex paint is that exterior paints will have mildewcides and UV blockers in them to prevent mildew growing on the paint, and the paint chaulking due to exposure to intense sunlight.

Dimensional changes due to changes in temperature in metals are absolutely tiny compared to dimensional changes in wood due to changes in it's moisture content, so you can use an interior paint on your door. It's just that depending on where you live, you might need the additives that come in exterior paints, and I really don't know if Envirogard and Monamel come in exterior versions.

This message has been edited. Last edited by: Nestor,

Every new metal door I've ever installed has a sticker on it stating to use 100% Acrilic Latex.
It also goes on to state to not paint it a dark color if it's in direct sun light.
Make sure to degrease the door to get old hand grease off of it.
Always remove the door knob.
What works best is to remove the pins out of the hindges, lay the door down flat on saw horses, remove the hindges, paint all the low areas with a quailty 2-1/2" sash brush and roll the rest with a 6" foam roller.
By doing it that way it should come out as smooth as if it sprayed.
Try to paint a door without removing it can be a real pain. You always end up getting paint on the jambs, on the hardware, on the floor, the bottom does not get painted, your going to end up closing that door and having it stick to the door stop trim.

I always wondered how an automotive paint would work on a metal door. After all, they are both exposed to the same weather and heat conditions
If I had a metal door , I would give it a try with the proper primer and paint. If it dont work, nothing lost except a couple of bucks

very good chance the primer on the door would not be compatible with an automotive paint. aka the solvent in a Dupli-Color can or traditional lacquer or enamel would lift the primer, and you'd have a metal-flake door for certain

I am not sure whether there is general availiability of the more recent water-based auto resins, and again, there could be a chemical incompatability between systems. most of the really good stuff in enamels is a catalyzed system, and most of the catalysts are seriously unfriendly chemicals, as in full-body supplied-air respirator systems.

heck, the automakers had enough trouble with their designated primers and designated paints not staying together. many the customers who demanded recalls from the big 3 due to peeling paint, especially in browns, blues, and silvers. the lucky few got a free quart of standard paint, which of course needed to be cut 10:1 with solvent, no labor, no spraying.

if you had a clean bare door you could wash with alcohol, then petroleum, then alcohol again, 220-sand, apply an etching primer, and then spray 4-5 coats and three clears in a paint booth, I think that would be a 50-year paint job. 70 with Imron.

but those conditions are not going to happen.