Peeling paint & stains: Which first - binding primer or stain sealer?

[daftcowuk]

So, I'm about to start repainting a bathroom that has both peeling paint and stains on the ceiling... nothing too major but both the stains and peeling paint still need to be dealt with regardless.
So, I bought the follow but realise now that I dont know which to use first.
- Zinsser Peel Stop Binding Primer
- Zinsser B-I-N Primer Sealer Stain Killer
In my wee head it would make more sense to bind the peeling paint edges first and then seal the stains but can anyone confirm if this is indeed correct?

 

[opps]

Without seeing the ceiling it is hard to provide definitive advice, nevertheless...

IF the paint is only peeling at the edges then the first of the Zinsser products may be OK with regards to gluing down the edges. It is potentially a bit of a bodge though. Ideally you would use a decent scrapper and or sander to remove the loose paint.

BIN is a great stain blocker but blocking stains may just be hiding problems in the short term. BTW BIN is pigmented shellac suspended n alcohol, ignore the cleaning advice on the back of the tin and use household ammonia to clean your brushes. Ammonia is an alkali, it completely breaks down the paint and leaves you with white dust in water (after the ammonia has evaporated off) which can be poured down the sink. Zinsser recommend using meths. The meths just dilutes the paint.

If we discount the possibility of water ingress from above the ceiling them it would suggest that the root of the problem is possibly condensation from bathing and showering. You can start by using your two Zinsser products, in the order you mention, but you still haven't dealt with the lack of airflow.

You can buy some time by using a decent waterbased eggshell on the ceiling. It will provide a "vapour proof" membrane but you may end up with mould overtime.

Ideally, you will have a sufficiently sized extractor fan, preferably with a humidistat that keeps the fan running until the moisture level is sufficiently low.

If any of the above doesn't make sense, please post back.

Oh, and welcome to DIYNOT

 

[daftcowuk]

Thank you so much for your reply!! Your advice is great!!
You will be pleased to know that I have already been scraping all the loose peeling paint off the ceiling today! Turns out what I thought was just a few wee peely bits actually ended up in the paint coming of in big sheets! I have tried sanding the edges back but I was sanding more plaster than paint so am hoping that all the coats of primer, sealer and paint will make the edges looks a bit less obvious.... unless your going to tell me otherwise...??
The bathroom window is never fully closed so should that not be enough airflow?
A bit of background, there was a leak in the roof a few years ago and I think the bodge was when the ceiling was repainted afterwards. I was hoping that now everything will be properly dried out, if I take the time to seal the stains and deal with the peeling paint (that I though must surely have been due to the water damage) then it would go a long way to making it look much better but again, any advice on this would be appreciated.

 

[opps]

Hi DCU

Kudos for removing the old paint. If it came off quite so easily, then it deserved to go. I suspect that the first (mist) coat wasn't sufficiently diluted.

If you no longer have any loose bits of paint I would recommend using diluted matt emulsion over the bare plaster as a seal coat (as per the manufacturer's instructions). I don't see the need to pay for the Zinsser Peel Stop.

Then apply the BIN where the stains keep bleeding through. Follow that with one coat of full fat emulsion. If the paint edges are still visible consider using Toupret RedLite filler to feather them out. It is a lightweight filer that is easy to sand back and the dust does not cling to everything.

Apply one or two coats of emulsion over the RedLite.

Belt and braces, apply two coats of waterbased eggshell over the whole ceiling if you want a finish that can be washed.

Apropos the current airflow- I cannot say if the window is sufficient or not.

Best of luck.