A pointer on how to repaint these 1930s casements?

[MRodent]

Hello,

I have a 1930s semi. I'm on the point of renovating the casements, all solid pine, and possibly never repainted since the house was built.

I will be replacing the existing (single-glaze) panes by vacuum glazing panes, and I'm also going to install weatherstrip (AQ21) round the edges of all the sashes. I'm not asking for advice on that here, only on a painting question. All the paints I'm going to be using are OIL-BASED: primer, undercoat and topcoat (gloss white).

The wood is sound except for a couple of rotten sills, which I'm going to replace.

The state of the paint varies greatly throughout the house. I'm looking for advice on how you would tackle things if it were your house. In short: would you strip back EVERYTHING to the bare wood and then start priming? Or would you paint ON TOP on some parts of these, where the paint still looks thick and protective? If so, would you first apply undercoat, or just dive in with the topcoat?

Generally speaking the interior paint is in better condition than the exterior.

Please find attached five photos. Please bear in mind that I'm aware that these windows all need a good CLEAN!

These are my comments on each attached photo

One: you can probably see that the paint on the interior of the fixed frame looks pretty good. However you can also see that at the bottom right of the interior of the sash, the paint is peeling away, revealing the bare wood.

Two: again, the interior of the fixed frames (and here of the sash at the left) looks pretty good to me: would it be overkill to strip all this paint back to bare wood?

Three: as I say, these windows certainly need cleaning! You can probably see that the paint on the exterior sill is getting pretty thin.

Four: pretty bad condition of the paint on the exterior bottom batten: but the wood is still perfectly sound. This will obviously have to have all the paint removed, and repriming... but what do you think of the upright batten? Again, would it be overkill to strip all the paint off this?

Five: exterior sill. Again, this sill is definitely not rotten, but it has obviously suffered over the decades. After all the paint is stripped the wood will need some TLC (filler) before priming.

Thanks for any advice!

 

[Wayners]

Always undercoat bare wood or existing gloss.

 

[MRodent]

OK, thanks.

So is the idea that I basically divide the different parts of these frames and sashes into two categories:
- some areas, where I'm going to strip all the paint off, back to the bare wood, and apply primer (then undercoat ...)
- the other areas, where I'm maybe just going to lightly sand the existing topcoat to get some kind of key (for some fresh undercoat)
...?

(the thing is, there is hardly anything on Youtube which explains what to do in this situation: mostly these vids seem to show extremely poor condition sashes and frames where the only option is obviously to strip back to the bare wood over the whole thing)

 

[Wayners]

Undercoat will go on bare wood.
You could use B-I-N AQUA but it's water based as a plan B

 

[sparkwright]

Sand every scrap of wood.
If you are insisting on using oil-based paint, prime all bare wood with oil-based aluminium wood primer.

 

[opps]

Sand every scrap of wood.
If you are insisting on using oil-based paint, prime all bare wood with oil-based aluminium wood primer.

Why?

I haven't used that stuff since 1989. I was asked to use the paint because I was dealing with a door with resinous knots. I was only 19 at the time. It didn't stop the knots from bleeding. It was later that I discovered that using a heat gun to sweat out the resin, or just pulling out the knots might have been better.

My go to oil based system for painting customers' windows is the Dulux Trade (oil based). Post 2010 VOC compliance, I complained about their waterbased (blue) primer being a mare to apply over large areas on hot days. They, surprisingly, recommended using their Cuprinol clear wood preservative as a primer. If the timber is sound, I just use cheapo Leyland Trade acrylic primer as the base coat, and then two coats of the oil based DWS over the top.

 

[sparkwright]

Why?

I haven't used that stuff since 1989. I was asked to use the paint because I was dealing with a door with resinous knots. I was only 19 at the time. It didn't stop the knots from bleeding. It was later that I discovered that using a heat gun to sweat out the resin, or just pulling out the knots might have been better.

My go to oil based system for painting customers' windows is the Dulux Trade (oil based). Post 2010 VOC compliance, I complained about their waterbased (blue) primer being a mare to apply over large areas on hot days. They, surprisingly, recommended using their Cuprinol clear wood preservative as a primer. If the timber is sound, I just use cheapo Leyland Trade acrylic primer as the base coat, and then two coats of the oil based DWS over the top.

I wouldn't rely on the aluminium wood primer for the knots, I would use a separate knotting solution first.
I have always found the aluminium wood primer to give longer lasting results on weathered surfaces.

 

[opps]

I wouldn't rely on the aluminium wood primer for the knots, I would use a separate knotting solution first.
I have always found the aluminium wood primer to give longer lasting results on weathered surfaces.

Fair enough.

I guess that, when faced with weathered wood, I tend to sand away the weathering. One of the advantages of having lots of stoopidly expensive Festool sanders. I wouldn't want to try doing that by hand.