Glazing silicone and what to do when windows need a repaint?

[Krome10]

Hi all

I'm in the process of giving my windows a once over. I've sanded and removed all the existing glazing sealant/silicone and will soon start on the painting.

I was planning to finish off with Dow Corning for the glazing sealant as this seems to be a common and well regarded choice. But then I got to thinking (I've had plenty of time to do that whilst up the ladder!!!).....

When the time comes in a few years for another paint job, I'll likely have to remove the Dow Corning - ESPECIALLY if I change colour, because the DC is not overpaintable, and there will be some of the paint beneath the clear sealant/silicone.

So my question is.... Is this just one of those things? Or do people with more experience/professionals have a way around this? Should sealant/silicone always be removed as part of a paint job? Are there techniques involved that would help avoid having to do that? Or is it best to use an overpaintable product?

These are the kinds of questions going around upstairs and I would love to hear what you guys think.

Many thanks

Max

 

[RobinBHM]

There isnt normally any visible silicone sealant showing on a window.

Im assuming you are talking about a timber window, double glazed with external timber beading?

Some window manufacturers make their beads with a small rebate to the glass face which is then siliconed (or if internally beaded, same thing but rebate is on the sash.

If you want an overpaintable silicone, then maybe use ms polymer or an acrylic putty:

http://www.thegluepeople.co.uk/index.ph ... ucts_id=47

http://www.sealantsonline.co.uk/Product ... ty/WIN7506

I would avoid clear silicone as it gets dirty after a year or so. The best option is to use something like the above, then overpaint.

Both of these products are sticky and somewhat awkward to use, so a bit of practice may be worth doing before trying on a window!

 

[cowfoot]

As above...but if you are forced to paint over silicone, Zinnser Coverstain as an undercoat helps.

 

[MMUK]

I assume you are talking a perimeter seal to the brickwork? I would seal with a clear low modulus silicone (try Eurocell, under £2 a tube) and run a line to seal it. Then bed in a hardwood fillet trim which can be painted or stained as often as you like. The silicone is completely hidden and it won't interfere with your decorating.

 

[Sir Percy]

CT1? Widely available, and can be overpainted.
http://www.ct1ltd.com/en/ct1.html

 

[Krome10]

Thanks for the helpful replies - really appreciate it.

Im assuming you are talking about a timber window, double glazed with external timber beading?

Yes, that’s right. And I should have clarified that I am discussing the silicone which seals the gap between the beading and the glass, NOT the gap between the frame and the wall.

I assume you are talking a perimeter seal to the brickwork?

As above

RobinBHM – I’m not sure I followed everything you wrote. As far as I can tell, on my windows you can see a little bit of the silicone – certainly from outside, and you can see a little of it from the inside as well. For that reason I have favoured clear so that it looks better from the inside. But I’ll bear your point in mind re it getting dirty.

Thanks also for the links, I’ll take a look at those.

Cowfoot – I’ve used various Zinsser products in the past and always got on well with them. Never used Coverstain though and was not aware it can be used on silicone. So does it work even on the silicones which state clearly that they cannot be overpainted? Well handy to know if it does – thanks for the info!

MMUK – good point RE the trim (although a touch off topic for this thread), I hadn’t thought of that and may well take that option. I guess it won’t matter that there are gaps down the side of the trim because the frame will be siliconed to the wall behind it. (In fact, it already is).

Sir Percy – CT1 I’ve used before and didn’t get on with it so I’ll give that a miss, but thanks anyway.

Cheers all