How to prep and paint timber windows and doors?

[Adam78]

I have timber doors and windows on a 1940s semi.

On the front on the property the windows and doors have a dark oak stained finish.

On the rear they have a dark brown gloss painted finish. I can see some paint is flaking off and there appears to be a grey finish underneath - i'm assuming its some primer?

I want to re paint them all with dulux weathershield exterior satin paint (conker) which is a dark brown.

Some of the timbers have some rotting.

How should I prep the surface on the windows and doors to the front of the property where they currently have a stained finished.

• Does it require a primer.
• What grade sandpaper should i use.
• Do I apply silicone to the edges and window pane and beading before or after painting?
• What type of silicone should i use?
• How do i fix the rotting - filler?

Please advise of the steps.

How should I prep the surface on the windows and doors to the rear where it currently has a gloss finish.

• Will this require a primer?

I've noticed in the past when I've painted windows and doors that they don't properly shut due to the extra layers of paint. How do you mitigate this?

Any tips and advice will be appreciated.

 

[endecotp]

Does it require a primer.

Primer is applied to bare wood. Only apply primer if you’ve sanded back to bare wood.

It prpbably needs undercoat though. Read the instructions on your Weathershield and do what they advise.

What grade sandpaper should i use.

Something reasonably rough to start with, then maybe finish with something finer. Also consider using a scraper.

Do I apply silicone to the edges and window pane and beading before or after painting?

No. (Huh?)

How do i fix the rotting - filler?

No. How bad is it? Post photos. You may need to replace bits of wood, or cut out the rotten parts and fill with two-part filler.
There are also “hardener” products that you can apply - I’ve never used them.

 

[jj4091]

https://www.acepaintsfurniture.com/can-paint-stained-wood/

 

[foxhole]

https://www.diynot.com/diy/forums/decorating/

 

[Blagard]

Adam78,

Do not use any silicone on anything you may need to paint or stain - silicone and paints simply do not get on together!
Where you feel the need for a sealant then consider decorators caulk - for gap filling mostly internal or better for external use a paintable mastic sealant. - you need to check the specifications to see which ones are paintable

For areas of rot you need to remove any rot and either cut out and splice in new timber or for minor repairs get out as much rot as possible then treat the remaining with something like Ronseal wet rot treatment then follow using a two part filler such as Ronseal high performance filler. Please note on those 2 part fillers there are usually cheaper ones at Toolstation and Screwfix under different trade names like everbuild. The fillers come in various colours and whilst not that important to areas painted it does help to match if you can.

When it comes to "sandpaper" cheap ones will usually tear, wear out and clog so to a degree you will get what you pay for. Course ones like 60grit are agressive and may be the first one to use where you need to get things level quickly. Then switch to a less course grade like 120grit and after that 240 grit which may leave your surface good enough for painting. All decoration is only as good as the preparation and for really fine work you will find decorators using finer grits like 600 or more for a really great finish. But it also depends on the paint used as high build paints may cover imperfections better than thinner paints but will not give the same quality of finish. If the prepared surface does not look smooth and flat the finish never will!

Edit:
Primers are needed whenever you get back to the bare surface of the underlying material or where you have used a filler. Wood frames do "move" between winter and summer so an opening light painted in the summer may stick in the winter. Timber that is in poor cocndition can move a lot! Keep it in mind when you doo repairs as replacing a complete casement may be the only option depending on the extent of any repairs needed and the condition of the timber. If a window or door sticks even a little bit it will be far worse after painting. The clearance on good quality timber should be an old penny (1d) gap or about a modern 2p gap! If done in a dry summer a larger gap should be considered. So be prepared to plane off material or remove all old paint if you don't have the clearances. I favour priming all surfaces of timber that is fitted such as rebates and glazing beads as it adds protection to the timber and improve bonds to putty etc where used.