Repairing Wooden Beading on external windows - What sealant!?

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Hi all,

I have some old windows that have oak wooden beading (no putty) externally and during extreme rain there's some water that gets in, it's fairly clear to see its getting in on the lower edge of the window between the glass and wooden beading.

Is the best way to fix this to gently pull up the external wooden beading, run a line of silicone and then reinstall wooden beading I'm guessing with panel pins?, then for good measure run some sort of caulk or some such between the joint of glass and wooden bead top and bottom and in corners?

Questions was do I reinstall wooden beading with pins or wood glue? (or do I use some putty in a gun under the bead!?)

Also i'm assuming silicone is fine under the beading, but what do you use after having reinstalled the wooden bead, as conscious clear silicone will likely make a good seal but cant be painted over? (I'll likely repaint all the windows in summer when the weather isn't so awful)

Is there such a thing as a weatherproof external paintable sealant suitable for glass and wood that would be best? (or can i just use putty in a gun as a selanet under the beading AND on top after having pinned wooden beading back in place,

Thanks all
 
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Single glazed or double glazed?

if double glazed, there should be an air gap between glass and rebate, so just run a bead around enough to bridge the gap not fill it.

hybrid MS polymer sealant is a silicone that is paintable, you need a sealant / mastic not a hard setting glue type - I believe CT1 is a hybrid, but it’s more of a glue.

you need stainless steel pins - steel will rust esp in oak which has a high tannin content.

if it was me, I’d plane a chamfer on the bottom bead so when refitted you end up with a V against the glass - then fill with mastic, that gives you a protected, decent size mastic bead sealing where most rain water will go.

when using mastic, I would do it on the back of the bead that ends up facing the glass. On bottom bead don’t seal between bead and rebate face - so any water getting in can get out.
 
Single glazed or double glazed?

if double glazed, there should be an air gap between glass and rebate, so just run a bead around enough to bridge the gap not fill it.

hybrid MS polymer sealant is a silicone that is paintable, you need a sealant / mastic not a hard setting glue type - I believe CT1 is a hybrid, but it’s more of a glue.

you need stainless steel pins - steel will rust esp in oak which has a high tannin content.

if it was me, I’d plane a chamfer on the bottom bead so when refitted you end up with a V against the glass - then fill with mastic, that gives you a protected, decent size mastic bead sealing where most rain water will go.

when using mastic, I would do it on the back of the bead that ends up facing the glass. On bottom bead don’t seal between bead and rebate face - so any water getting in can get out.
Single glazed (listed buildings, sigh)

all the beads are triangular, they are basically exactly the shape of putty but in oak (i.e triangular so are angled correctly), ok will look out for a hybrid MS polymer sealant
 
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Single glazed (listed buildings, sigh)

all the beads are triangular, they are basically exactly the shape of putty but in oak (i.e triangular so are angled correctly), ok will look out for a hybrid MS polymer sealant
ideally you should deglaze, then bed the glass on clear silicone, then run MS polymer around to fill gap between glass and rebate, then apply MS polymer to glass all way around then fit beads

it is was I’d aim to get to get a bed at least 1mm thick between glass and bead - especially on bottom bead.

treat ends of beads with end grain sealant

leaks through the bottom beading often are the cause of the sash joints rotting
 

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