garage door repaint

[bludger]

Hi,

My garage door is a real mess. I'm halfway through using a hot air gun to scrape it all back to the primer or bare metal - some parts have one coat of paint, others have four.

When I've done scraping, I intend to use a ball of steel wool to remove any bits and properly abrade the surface(s) for painting. Am I right in doing this? And if I am, what grade of steel wool would do the job best?

Another question. I intend to use a combined primer/undercoat, giving the door two coats of that. Then I'll put on two coats of gloss. Now, both these paints state that they are recoatable in 4 hours. If I time it right, does this mean I wouldn't need to abrade in between the coats of new paint?

Bit of a long post, I'm sorry.

 

[deandiy61]

unless you're taking the whole door back to bare metal then you'll have paint edges, they're hard work by hand. I used circular abrasive discs on a rubber backing plate and screwed to a spindle operated by a drill. Try to use progressively finer discs. There are a range of more sophisticated abrasive tools available now but their discs/pads might not be cost effective on a painted metal garage door.

 

[dcdec]

Combined primer/undercoats are normally water based, so make sure it is an oil based one or it'll rust. Personally i'd use a specific metal primer, then undercoat and then top coat. Better off as said above and use a sander to knock back anything you've missed. You should degrease the door though, which basically means giving the door a quick clean with brush cleaner or similar.

 

[footprints]

I spent best part of a week on painting my garage door darn great thing 9ft wide. A year later it fell off the pivots and almost flattened me. Got loads of quotes they all said the same "that door is too big for that sort of system"
I ended up replacing it!

 

[bludger]

Hi,

By now I expected to be able to say the jobs done and thanks for the advice. But I've made an awful mistake. The prep went well and so did putting on the primer. But then, I picked up the wrong tin and put on the topcoat!

What can I do now? I could mix the rest of the topcoat with the unused undercoat, fifty fifty. I could just use the undercoat paint as a topcoat. Or I could put on the undercoat as an undercoat and then buy some more topcoat. What a stupid mistake.....

I've used oil based paints as recommended, by the way. Please don't tell me to burn it off and start again.

 

[footprints]

No you don't need to burn it off you need to scrape the whole door clean with
your fingernail and a tooth brush, only kidding!

It's up to you, as long as it has a primer topcoat will take ok.

The worst that will happen is either the colour (if using a paint that requires a coloured undercoat) will not be true to the shade card or the paint will have a thin appearance with the old paint underneath grinning through.

Undercoat does two things it gives a depth of colour to the top coat which is a trifle less opaque than undercoat and it flows out to level the surface.

Either undercoat over the new paint or just try a second topcoat I would try the second topcoat first

 

[bludger]

Hi again,

Okay, the job's finished and if I say so myself it's come out pretty well.

Thanks to those who helped me along - as usual in this forum.