Any painters/decorators?

Tigger.ufo

Lady Penelope
Messages
5,922
Name
Heather
Edit My Images
Yes
Best way to prepare garage doors (yes, there are 2 of these beauties!) for repainting?

Last painted 25+ years ago over black and yellow gloss. The yellow seems to be very well stuck on the wooden doors and I have started scraping the blue and black off with limited success.

Is there a trade secret or do I just have to persevere with scraping?20201021_101814.jpg20201021_101825.jpg20201021_101856.jpg
 
you could try this.
I used an older version it to strip my garage door a few years back easy to do and saved hours of sanding and stripping, as they say don't scrimp on the washing down and neutralising.
 
TBH, I'd wait for next spring to start the job.

The key to a good finish is good preparation so I'd scrape as much as will come off easily then set to with a sander. The grit depends on how bad the surface is - that looks like it might need 80 to do the worst bits then go finer as the surface improves. It's possible that the heat that an electric sander will generate might start previously sound (looking!) areas to start flaking; if that happens, stripping might be the only real answer but the doors will then need extra coats of primer and undercoat. Personally, I'd avoid heat stripping. Reasons? Windsor Castle and (probably) Notre Dame spring to mind!
 
TBH, I'd wait for next spring to start the job.

The key to a good finish is good preparation so I'd scrape as much as will come off easily then set to with a sander. The grit depends on how bad the surface is - that looks like it might need 80 to do the worst bits then go finer as the surface improves. It's possible that the heat that an electric sander will generate might start previously sound (looking!) areas to start flaking; if that happens, stripping might be the only real answer but the doors will then need extra coats of primer and undercoat. Personally, I'd avoid heat stripping. Reasons? Windsor Castle and (probably) Notre Dame spring to mind!

Thanks for detailed reply!

There is an 8ft polycarbonate roof over the front of the double garage with trees as well so pretty sheltered from the elements and I have put off doing it all summer while painting the (exposed) house. Still not finished that yet but the rest will wait until the weather is better ... probably Spring! The garage owner is not too fussed about finish but I want it to look ok and am willing to do a reasonable amount of prep as he is paying me by the hour. :)
 
As @tarric says, a chemical stripper would be what I'd suggest, though they are nothing like as good as nitromors used to be now..
If you use a random orbital sander then you ought to wear a mask, and ideally connect it to a dust extractor(vacuum) as there may well be lead-based paint which is carcinogenic and 80g abrasive is about right to start, then 120g to get a smoother surface. Wash down well with a degreaser then wipe with meths before painting to help adhesion.
Without seeing it close up its not easy to say, but could be a lack of cleaning that's caused the paint to peel, but you say the doors are wooden - Is that right?
 
As @tarric says, a chemical stripper would be what I'd suggest, though they are nothing like as good as nitromors used to be now..
If you use a random orbital sander then you ought to wear a mask, and ideally connect it to a dust extractor(vacuum) as there may well be lead-based paint which is carcinogenic and 80g abrasive is about right to start, then 120g to get a smoother surface. Wash down well with a degreaser then wipe with meths before painting to help adhesion.
Without seeing it close up its not easy to say, but could be a lack of cleaning that's caused the paint to peel, but you say the doors are wooden - Is that right?


Thanks Steve.

Yes, the doors are wood underneath all the paint. I'm sure you are right about the preparation that was done last time (or the time before!) The yellow gloss seems to have been done properly and then black gloss slapped on top followed by some sort of pale primer/undercoat with blue gloss done at least 20 years ago!


This is the sander available to me. Can I just plug my dyson into it to catch the dust? I have a respirator mask which I will be using.
 
Last edited:
Thanks Steve.

Yes, the doors are wood underneath all the paint. I'm sure you are right about the preparation that was done last time (or the time before!) The yellow gloss seems to have been done properly and then black gloss slapped on top followed by some sort of pale primer/undercoat with blue gloss done at least 20 years ago!


This is the sander available to me. Can I just plug my dyson into it to catch the dust? I have a respirator mask which I will be using.
That surprises me (them being wooden)
I don't know that sander, and the dust outlet looks pretty small, but a bit of gaffa tape will join it to your Dyson if it has a tube of some sort, but fine dust and running an expensive hoover for an hour or two at a time might not be a good thing - a Henry is a cheaper alternative to a proper dust extractor if there is one available (you might be able to hire one). I've heard tales of people burning out expensive vacuums while sanding....
I'd still suggest using a chemical stripper first of all as it'll save you hours of unpleasant work, but you will need to be ready to scrape fast once it has softened the paint, so do a metre or two at a time.
However, I know you said that you want it to look good but I'd be surprised if it will, as without a massive amount of work you'll still get the different layer thickness showing through (hmm, not sure how to say that, but expect you'll know what I mean) so you might be just as well off scraping off the loose, a quick sand, then clean off using something like Krud Kutter - https://www.decoratingdirect.co.uk/viewprod/k/KRUDKUTTER_ORIGINAL_CLEANER-DEGREASER/ then meths, or just loads of meths then a couple of coats of a really good bridging primer like Zinsser Cover Stain - https://www.decoratingdirect.co.uk/viewprod/z/ZINCS/ which stinks but has never let me down, or a water based one which I'd be slightly hesitant to suggest, like Zinsser 123 - https://www.decoratingdirect.co.uk/viewprod/z/ZINBE/ or 123 plus - https://www.decoratingdirect.co.uk/viewprod/z/ZINBE/
This is what I'd be likely to suggest to a client.
Then you can use any exterior paint you want. Good luck..
 
:plus1: for a Henry rather than a Dyson. 1/3 sheet sanders are great for large areas but not ideal for getting into the tight corners or doing the little reveals (sides of the "frames".)
 
:plus1: for a Henry rather than a Dyson. 1/3 sheet sanders are great for large areas but not ideal for getting into the tight corners or doing the little reveals (sides of the "frames".)
The problem I have with 1/3 sheet sanders is that they are too big - my main sander (a fancy Festool) is same shape but about half the size which is perfect for most of what I do, but like you say a detail sander for the fiddly bits, or pointy fingers and a decent abrasive - Abranet is perfect and I forgot to mention it earlier. Its mesh based so dust gets sucked through it (when attached to a dust extractor) so it lasts longer and makes the job much easier and better.
 
Do you have a commercial door stripper somewhere near? That could dip them for you and go right back to the original wood.

Having suggested that, it might affect the original wood.
 
The 1/3 sheet sander will do that door ok.
I used mines to sand my cathedral style kitchen doors and it got right into the edges.
I agree they're not light, but not that heavy either.
I did my garage door no problem in around an hour.
I'd sand the flaky bits with 80 grit and the rest with 120 or 240.
I think that would be easier than stripping the whole door. As it's outside, I'd wear a mask but wouldn't use a hoover etc....
 
Thanks all for replies. :)

I think I am going to go with scraping the loose stuff off and then sanding ( I also have a mouse type sander available.) I have explained that I will not be getting much of a finish and the owners reply was "It will be better than it is now!" He is a smashing guy who used to do stuff to his house but can't manage it now and is happy for me to do things for him ... and I am happy to do most stuff with instructions!
 
Update time!

Pretty much ready to paint. Have thoroughly washed down with sugar soap and rinsed well.

Next question is do I paint the framework first and then the panels? Start at the top and work down? Another way?

Thanks!20201125_104538.jpg20201125_104555.jpg
 
I'd undercoat everything first then finish the frames. Once I was on the doors themselves, I'd do the panels first (yup, start at top), then the horizontals followed by the verticals and finally the edges and bottom. If you have the time, it's probably worth masking off the frames with old newspaper while you're doing the doors - saves touching up/wiping over too much.
 
I'd undercoat everything first then finish the frames. Once I was on the doors themselves, I'd do the panels first (yup, start at top), then the horizontals followed by the verticals and finally the edges and bottom. If you have the time, it's probably worth masking off the frames with old newspaper while you're doing the doors - saves touching up/wiping over too much.
Bugger! Do I need to undercoat it as well? I am only actually doing the doors not the frames at the mo. No bare wood.
 
As Nod says, panels first, then I work out which order to do the bars by looking at the joints, and end the painting on the long bars - in this case the vertical ones. That way any brush marks go with the length of the bars, and hopefully the grain!
 
i would consider using a small roller to be honest, i have recently replaced all my internal window linings with wood and i rollered them with a very small roller for the gloss work, it was loads easier than a brush and had a much better finiish
 
Bugger! Do I need to undercoat it as well? I am only actually doing the doors not the frames at the mo. No bare wood.


Depends how good a job you want to do and how long you want it to last. I always use undercoat, even if the top coat says it's a one coat solution. (In fact, I avoid the one coat solution products because they tend to be a bodge!)
If you're not doing the frames, just mask them off before starting on the doors.
 
Back
Top