How to re-seal individual window panes?

[DIYNotIan]

Hi there

I'm in the middle of having some windows re-painted. A few of the panes leaked last winter, so as part of the job I'm going to have them resealed.

This is the kind of thing I have:

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• DIYNotIan
• 14 Sep 2012
• 1

The seal varies in quality from pane to pane. On some panes it is in worse condition, especially in the corners. In some it is non-existent.

My deccy has said he will run clear silicone around the ones that need it. Is that what is usually done in these scenarios? If not, what is the best thing to do?

Also, at what stage of the painting process is it best to do it?

Cheers

Max

 

[DIYNotIan]

One other thing.... around the outside of the frames was some pinkish putty type stuff which has fully deteriorated. That's all being scraped out. What's best to replace it with and again, at what stage in the painting process should that be done?

Cheers.

 

[Burnerman]

Prsonally I'd take those window beads out, (checking for any rot at the same time), scrape out any debris from behind and then reseal the beads using putty (from tubes), tacking the beads back in the same place that they came from. If the panes are loose, this should be dealt with now.
Excess putty is then trimmed away from where the bead contacts the glass.
A quicker but less permanent way is to apply a thin bead of silicone at the corner where the bead meets the glass.
John

 

[DIYNotIan]

Thanks for the advice. I think our chappie is planning to do it the latter way, but not just in the corners.... I think (and will check with him) that he is aiming to run some clear silicone all the way around (so that the silicone is run along ALL the areas where the bead meets the glass). And I think the new silicone will be applied on top of the existing "stuff"...

 

[Burnerman]

Well, thats better than nothing and will work out much cheaper....he will need good adhesion between the existing timber and the glass though.
A proprietary frame sealant is used between the ouside of the frame and the brickwork, painted over afterwards.....but when the old stuff is hacked out its worth checking for any rot in there at the same time.
John

 

[DIYNotIan]

Thanks John, much appreciated.

When you say "proprietary frame sealant", what should I be looking for exactly? And do you recommend any particular makes?

Cheers

 

[Burnerman]

The worlds your oyster here, but for me its Dow Corning 791. (Frame sealant).
A fiver a tube, and in a few colours. Its DC 799 for glass.
John

 

[DIYNotIan]

Thanks John... One more thing, is the frame sealant available in various makes in a clear/see through finish?

And if he chooses to finish all the painting first and then do the sealant afterwards (in clear), is that ok or a no-no?

Cheers

 

[Burnerman]

Typical frame sealant finishes are clear, white, brown and black.....the sealant is usually applied first and then left to 'skin' over prior to paint treatment.
John

 

[DIYNotIan]

Hmmm... Looks like he'll be doing it back to front then.... I'm not so worried about how it will look, so long as it is effective in keeping the weather outdoors!

 

[DIYNotIan]

Yep, he's definitely doing all the painting first and will do the silicone around the panes as a final stage.

Will that help stop the water come through?

 

[Burnerman]

Any wood treatment on the inner window jambs which can't be seen can only be a good thing.
So long as the joiner / glazier gets good adhesion between the sealant and any glass or paintwork, all will be well.
John

 

[DIYNotIan]

Hi all

I did not mention it above, but as part of the work our chap replaced some units that had failed and were misting up. He's changed them today.... From what I understand, the silicone should cross from the wood to the glass, but it is not doing this on our job.

Here are some pics:

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• DIYNotIan
• 18 Sep 2012
• 1

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• DIYNotIan
• 18 Sep 2012
• 1

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• DIYNotIan
• 18 Sep 2012
• 1

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• DIYNotIan
• 18 Sep 2012
• 1

Obviously the painting has not been done on top of the silicone yet. When it is done perhaps it will bridge the "gaps".

What I wondered was whether the siliconing in the pics is good, ok , bad, awful, etc etc....?

Cheers

Max

 

[DIYNotIan]

Hi again

The pics above are part of a long line of workmanship I've been less than pleased with. I'm seriously thinking of calling the guy up tonight and sacking him or at least having a very serious chat.

Turns out the stuff he's used is not silicone, it is Evo-Stik Frame Mastic (trade only). From what I can see on the internet, this stuff states it is "Not suitable for bedding double glazed/insulating glass units into frames". Do the pics above count as "bedding"? When he actually installed the units he used some kind of tape around them. The mastic was only used as per above (to ***TRY*** and seal the wood to glass join).

The mastic looks awful the way it has been applied, and if it is the wrong product entirely then I'm not a happy customer!

To help make my mind as to what to do next, would someone please be able to tell me whether I am going to be able to remove the mastic if needed so that I can apply the correct product? Will the new glass panels still be ok or is there a chance they could be damaged/not able to be re-used?

Many thanks for sticking me me

Max

 

[Burnerman]

It does look like a bit of a gash job to be sure, Max
I can't comment on his choice of sealant as I've never used that one but it doesn't sound right, does it?
Double side sticky tape is commonly used to secure the glass units these days, but that doesn't help your issue.
Personally I'd get rid of that sealant, level with the glass beads, and then apply a line of masking tape on the glass, around 3mm from the edge.
A bead of clear silicone should be applied, followed by a finger smear that presses the silicone into the bead corner, and on the tape. Peeling the tape away after that gives a perfect straight edge.
I don't know how well that stuff has taken to the glass, but the edge of a chisel blade usually shifts it.
I detect a wholeheartedly peed off feeling here.....
John