stripping paint from lead bay roof

[kreyszig]

our house has a couple of good sized bay windows at the front, each with a convex lead roof - see photos here.
You can see in that picture that ours have been painted black, and next door white. The black paint is now cracked and peeling, and I need to strip it off. The balcony is the same. Any ideas on how to best go about this? I can't see a scraper working that well without tearing up the lead (especially given the shape of the roof), and I'm not sure what kind of chemical stripper I could safely use either. A heat gun also seems inappropriate... I've had a bit of a google and have seen wet and dry sandpaper suggested, which might be worth a go.

Any other ideas, I'm all ears! Also keen to hear opinions on whether I should repaint. I know probably the lead should be left bare, but I do quite like the look of the black paint (and the bays are north facing and in Wales, so we're not too bothered by the sun!)

 

[plasticpigeon]

I imagine a solvent based paint stripper wold be good. Now nitromoors doesn't contain dichloromethane it needs longer to act, so the poultice type strippers seem to be better. How about trying peelaway 7, that is a solvent based poultice stripper. Peelaway 1 is very effective, but it is highly alkali as it is a caustic poultice. My chemistry is not good enough to know how that would react with lead. Perhaps it would be ok, as metals usually react with acids to make salts as far as I know.

 

[malcolm]

I've used atripper to remove masonry paint from lead. That was apllied then blasted off with a pressure washer although that is messy especially if you park your car underneath. Peelaway would be better for acrylic paint and maybe a pressure washer could tidy after it has been removed to avoid scratching the lead.

I like the look of lead. Patination oil gives it a nice sheen.

 

[Flyfisher]

I imagine a solvent based paint stripper wold be good. Now nitromoors doesn't contain dichloromethane it needs longer to act, so the poultice type strippers seem to be better.

Yes, Nitromors used to be pretty good but has been seriously tamed by the banning of DCM. However, DCM-based products are still available for "professional” use according to this https://www.stripperspaintremovers.com/dcm-in-paint-removal/ and it is also easy to buy online if you fancy a bit of DIY chemistry. Cheap as chips as well.

But don’t buy more than you need thinking you can store it for very long. I bought a litre of the stuff, used half and stored the sealed plastic bottle in the garage. A year on, the remaining amount had evaporated!

 

[Cubist]

Hi Kreyszig,

That is a genuinely stunning house you have there, I'm glad the First Lady is not at home to see it as its a closer fit to her ideal than this place. You perhaps, should be just as grateful as she does tend to be rather aggressive when it comes to getting her own way and theres a risk she may decide upon invasion. Fortunately, she's away on business at present and, if truth be told, she's not that fond of Wales.

If you are really determined to strip the paint back to metal I would avoid using any form of abrasive; except perhaps to clean out small details. Whilst personally I prefer the appearance of a bare metal finish where lead is concerned, sanding its surface can produce a burnished, sometimes polished, effect that can take ages to weather back to a uniform patina. Also, close examination of the lead will show that it is likely covered in small dimples and craters formed when the lead was laid and shaped to fit the canopy. Frankly, you can expect to find thousands of them and sanding will simply leave spots of a old paint in all of them which would have to be removed by hand. On balance therefore I would recommend a chemical stripper of some sort, as suggested by by both Plastic Pigeon and Malcolm BUT I would test whatever stripper you may select on a scrap piece of lead, or a small out of sight section of the canopy, to see whether the effects on the final finish are acceptable. Also, some chemical strippers can be quite aggressive and you may need to apply something other than water to fully neutralise the chemicals - this too should be tested.

It's also worth remembering, whichever way you go, that some parts of the lead may be very thin where the builder has had to hammer it to fit the desired shape around and within corners and other details. Check carefully for thinning of the lead, or even holes, where it has been exposed to persistent drips, from say an overflowing gutter, it always surprises me how quickly such erosion can fully penetrate thin materials such as lead sheet and even slate.

Overall I would be tempted, particularly with a house of such obvious quality, to simply lightly sand the surface of the paint to provide a good key for a new coat, and also make good, and feather in, where the old paint has cracked or blistered.

Cheers,
Cubist

 

[kreyszig]

Thanks for the replies everyone, I wrote to barrettine and they suggested Peelaway 7 should be fine, but Peelaway 1 may react with the lead. Cubist, you flatter me! But you have got me thinking about whether stripping it fully is really necessary.

 

[Feltwell]

Definitely agree that chemical rather than mechanical removal is the way to go, and I’d suggest speaking to Strippers of Sudbury - who will not only advise which of their products will be likely to do the job but also sell you a test pack to try.

Lead weathers down to a nice finish, no need for any paint, it will just give you the same problem in years to come.

 

[88v8]

It's hard to keep paint on lead. It wants to make an oxide coat, that's how it protects itself. The oxidation causes paint to debond.
And them there's the thermal movement, as you say less so to the north. Thermal movement makes the paint crack, especially if it's thick.

If I were to strip the paint, I'd apply a minimal coat. Thinner paint is less likely to crack. Bedec say their Multi Surface Paint is OK for lead.

Alternatiely I'd look for an aerosol. A quick Google throws up a lot of fuss about elf n safety, but nothing useful. However, an aerosol would be a means of applying a thin coat.

Just had soldiers with our morning egg. Aha, they might sell you some paint http://www.dorsetmodelsoldiers.com/

Beautiful house. Envy ency.

Ivor