Painting galvanised garage door

[Mat]

My garage door needs a new coat but I'm not sure whether I need to strip the old paint or whether I can go straight over it with a new coat.

I know I need to wash it down thoroughly but do I need to undercoat it all or just the areas where the old paint has flaked off?



Also, can anyone recommend a good undercoat and paint?

Thanks

 

[Werewolf]

As it's peeling you'll probably need to strip it pretty much completely to get a good coverage and reasonable look with the new paint, which from personal experience is not fun although "biostrip"* may let you do it far easier than I managed when I had to do one.
It looks like it's bubbling/lifted in all the recesses from that picture, so by the time you've dealt with those areas your might as well completely strip it.

You'll need a good primer for galvanised steel, and then a decent garage door paint.


*An absolutely wonderful paint stripper that is water soluble and non toxic but seems to do better than nitromore despite being safe to handle and not affecting plastic.

 

[Mat]

Thanks. I was hoping I could get away with just priming the flaky bits :/

How long does biostrip take to work?

 

[Grimley]

Painted my garage doors just under a year ago. Your door looks a bit like mine before I started

Wire brush all of the loose paint off & sand the sound paint to give the new coat a good surface to bond to.

I did a bit of research of on what paint to prime it with. Some said red oxide but I was going to use a light coloured paint, soooo.... I bought this primer.

http://www.screwfix.com/p/zinsser-bulls-eye-1-2-3-primer-sealer-1ltr/10135

Its good stuff. Dries quickly so you can put a topcoat on the same day if the weathers right. Used a Exterior gloss paint (Wickes paint is good) A year later looks OK, Which reminds me, I must put another top coat of paint on them.....

 

[Mat]

That's more like it

I may be moving within the year so that should be ok

 

[setter]

For a better lasting finish id do as suggested above, strip the door right back to bare metal. For bare galvanised steel it needs treated with mordant solution.

http://www.paints4trade.com/mordant...OSVfoj_5XtxGW6EWq0DrOqzG1g8rLJ3UkkaAh0h8P8HAQ

Then primed with zinc phosphate metal primer which is the proper stuff for galvanised steel. Followed by undercoat then gloss to finish.

 

[Mark A]

No point wasting money on expensive undercoat and paint if you're just going over the top of that green paint. Looks like whoever did it just slapped some paint over the old stuff with no prep.

 

[andicole0]

Rub off the flaky paint, rub down the rest then use some Upol #8 on the bare metal areas. The a good top coat.
Andi.