Painting A Metal Front Door

[Plebonian]

Hi, I'm definitely not new to painting and decorating but this is the first time I've painted a front door.

Not a big thing admittedly, but it's metal and up until now the only thing I've painted is interior and 99.9% wood at that.

I thoroughly cleaned the door yesterday with sugar soap and warm water, scrubbed hard and gave it a wipe down. Once dry, it received a good sanding after which it received a wipe down with a damp cloth and then gave it a coat of undercoat.

Today, I gave it a light rub down followed by another wipe with a damp cloth and then gave it a coat of "Sandtex 10 Year Exterior Gloss" and yes, read the writing on the side of the can.

I finished at 11:30am this morning and while I was painting clear white spots appeared in a few places like there's grease spots on the door still. I painted back over and they went only to open back up later. I used a brand new paint brush, Artisan by Harris.

It does say on the tin that for best results use two coats but I'm slightly concerned with these spots.

Any suggestions please?

[teacake44]

Paint is separating, did you give paint a good stir first, was the door still wet from wipe down, did you use an undercoat,your better off using white spirit to clean first, not water.

[Plebonian]

Yes, it was given an undercoat - missed that bit out because TAB's new accoutn registration process is a pig - the "message" that appears in the browser went largely unnoticed as it only appeared for a split second and vanished again.

The paint was stirred for some time as well.

[Plebonian]

Oh, and door was definitely dry :)

[teacake44]

I can only assume that some moisture / water as got into your paint at some point, or the undercoat may have been to soft,( not dry enough) to take the top coat.

[gingejbee]

Metal front door...you're not in the local nick, are you?

[teacake44]

Undercoat can appear to be dry and ready, but underneath it can be like chewing gum, its always best to leave for 3/4 days in the perfect world, to make sure.

[The Builder]

Grease spots, I suspect, Plebs. Front doors anywhere near a road can easily pick up oil and grease from exhaust fumes.

I guess the door was already primed, but any bare metal should have a metal or universal primer applied first. It's a bit more of a problem now, since you have a finish coat already applied.

What is worth a shot, is to...

Really sand down the affected areas, taking the new top coat with it.
Cover these areas with a good stain/grease blocker.
(Zinsser "BIN"; or Ronseal "Stain Block"; there are others.)
Undercoat over the Stain Block, then top coat.

Same thing applies whether it's an aluminium or a steel door.

Note to Ginge: most volume builders use steel doors these days. So much more stable than timber. fewer call-backs. Just don't try to "shoot" a door in by planing it ;o(

[gingejbee]

^^thanks for info, Builder. Not something I've come across, or fancy having!

[bhg481]

It makes me suspect plebonian's real identity - apparently 10 Downing St has a metal front door.

[The Builder]

^^^^ Yessss, and, suspiciously, no cat-flap.

[Plebonian]

I'm in a new build that's 4yrs old. All the houses around here have metal doors. Let's just say it was very noisy putting the cat flap in!

The front door is well away from the road and we're actually by the back gate of a primary school and the path is about 8 metres away and the nearest road 3 houses away.

I'll leave it for now, will try and re-coat in a small area when dry and if it opens back up again, I'll take the electric sander to it and take it back. The undercoat was done just under 24 hours earlier so I suspect that's where the problem lies.