Solution for cleaning blown windows

[John506]

Not long moved into a house and every window except the bathroom has blown. They are all full of condensation, and as the condensation has dried in the sun it's baked on the glass and it is also all mucky and watermarked.

They are double glazed units in timber frames.

I have drilled 2 holes in the outside pane of each window top and bottom corner to allow an air flow to clear the condensation. I've seen on youtube were they do this and squirt some fluid inside and it cleans it up real nice, then they suck it out the bottom hole. They then seal the holes with little vents that allow the moisture out but not in.

I can't find any of this solution anywhere, was thinking of using acetone what do you think?

We are going to get new double glazed PVC windows but not for another 6 months so want a temporary fix for the current ones, be nice to be able to see out of them!

Thanks!

 

[Burnerman]

I wouldn't waste your time, John - any treatment would be expensive and not worth it.
Just go for new units when you can, and there are some good offers to be had.
John

 

[ladylola]

I remember a quite long thread about just this a couple of years ago. The poster ( sorry can't remember who ) was taking them out and somehow warming them in the sun to cure the condensation.
Drilling a hole in the glass? Seems an awful lot of work if you're going to replace in six months . Personally I'd just live with it.

Ah just found it
//www.diynot.com/forums/viewtopic.php?t=273970&start=0

 

[crank39]

Ah yes the famous 'I dry units out on my front lawn' thread, I do believe that poster hasn't come back to give up an update yet

 

[Gazman16]

You cant fix blown units on site, Anyone who claims they can is a con.
They can be dismantled cleaned and resealed in a factory but new units would be cheaper due to the labor involved.

If that many are blown I can pretty much garentee that your timber windows are not properly designed to take double glazed units. New ones will most likely fail in a few years too and you will have a hard time finding anyone who will garentee them for more than 1 or 2 years.

As the glass is about 60% of the cost of new PVC windows it would probably be worth getting some quotes to get the windows replaced.
If you have to have wood windows the cost will be quite a bit more but in the long run it will be cheaper than replacing units every few years.

 

[JohnD]

You cant fix blown units on site, Anyone who claims they can is a con.

yes you can. There are two steps:

ventilate the cavity to the outside so that it does not accumulate internal condensation

clean internal deposits away due to previous condensation

Surely you've seen videos of the demisting process?

 

[freddiemercurystwin]

You cant fix blown units on site, Anyone who claims they can is a con.

yes you can. There are two steps:

ventilate the cavity to the outside so that it does not accumulate internal condensation

clean internal deposits away due to previous condensation

Surely you've seen videos of the demisting process?

Its not a fix John though is it? It removes the misting but does not repair the unit. It is not a fix.

 

[foxhole]

You cant fix blown units on site, Anyone who claims they can is a con.

yes you can. There are two steps:

ventilate the cavity to the outside so that it does not accumulate internal condensation

clean internal deposits away due to previous condensation

Surely you've seen videos of the demisting process?

Definitely not a fix any air in the unit means moisture as well, that's why they are filled with inert gas.

 

[JohnD]

it is a fix in so far as the vent to the outside prevents it misting again, and the wash removes internal marks.

In the sense that it is now a non-misting unit, which has the insulating properties of a pocket of still air between the panes, it is now fixed. The incremental value of a special gas filling is insignificant.

Using an old construction techniques manual, I made a couple of double glazed fixed wooden windows years ago using the external ventilation of the void method. In those days it was recommended to drill a pin hole in the bottom of the frame sloping outward, and stuffed with fibreglass to keep insects and dust out.

The ventilation is to only equalise pressure as the temperature changes. It must be to the outside so that the void does not get humid indoors air in it.

One of them is still in use, though I can see faint dustmarks on the internal surfaces now. It insulates and does not mist.

 

[freddiemercurystwin]

Its not a fix John. It is removing the symptoms but no fix.

 

[JohnD]

tell me, if you have removed the misting, and stopped it coming back, and now have a window that you can see through, and contains a pocket of still, insulating air, in what way is it not a fix?

 

[freddiemercurystwin]

The gas used to fill the void has more thermal resistance than the outside air, hence gas is often used to improve the thermal efficiency of a window. So just allowing air from the outside into the void will reduce its thermal efficiency. Even if the original unit was not filled with gas it would have been filled with dehydrated air, which again has more thermal resistance than the atmosphere. It is not a fix. It is removing the symptoms but no fix.

 

[JohnD]

it is a fix in so far as the vent to the outside prevents it misting again, and the wash removes internal marks.

In the sense that it is now a non-misting unit, which has the insulating properties of a pocket of still air between the panes, it is now fixed. The incremental value of a special gas filling is insignificant.

what is the watts per sq metre of window per degree difference?

 

[freddiemercurystwin]

Not a lot I dare say, but you haven't fixed yours no matter how many times you say it.

 

[JohnD]

It doesn't mist up, I can see through it, and it insulates

That's all I ask of it.