Older DG pane units.

[zoothorn]

Hi chaps, happy Easter weekend to y'all. (DG = Double Glazed)

 

I've replaced typical 28mm upvc DG units before, removing beads etc.. but my old folks have (most shot/ fogged) older -thinner- DG pane units, set in timber frames.  Now, I can't see any way to replace the DG panes though. No beads.

 

The only reference I can think of, to determine what thickness the units are, is they look a similar thickness to a cd case. Perhaps 2mm glass, silver 8mm centre strip, 2mm glass ? (No idea, guess figures- I have no way to actually measure).

 

Could anyone help? Thanks, Zoot

 

 

[SteamyTea]

I changed my old 4-8-4 units to 4-16-4 ones in timber frames.

All I did was made my own external trim up  from some moulded timber.

 

Post up a picture of them, especially a corner and we can probably give you so much conflicting advice you will not know what to do, ever.

 

Here is my dirty rear corner.

 

 

Edited April 8, 2023 by SteamyTea

[Gone West]

5 hours ago, zoothorn said:

No beads.

I think there must be, how were the glazing units fitted?

[Gone West]

5 hours ago, zoothorn said:

to determine what thickness the units are

Back in the nineties I fitted 4/6/4 DG to wooden windows.

[zoothorn]

3 hours ago, Gone West said:

I think there must be, how were the glazing units fitted?

Hi chaps, thanks.. @SteamyTea 4-8-4 it surely must be then. Great that's the thickness sorted.

 

As to beading- well all I can see is what lookslike putty, but hardened perhaps by time, outside, holding the DG units in.. instead of beading.

 

Would this be right?

[Gone West]

12 hours ago, zoothorn said:

Would this be right?

I've not seen DG units fitted with putty and I thought the oils in the putty reacted with the seal around the edge of the DG unit.

[joe90]

56 minutes ago, Gone West said:

I thought the oils in the putty reacted with the seal around the edge of the DG unit.

Which is probably why they have fogged 🤷‍♂️, I don’t see why (like @SteamyTea) you can’t use a timber quarter moulding as long as there is room! And bed them on glazing silicone.

[Hobbiniho]

as said a bit strange to have putty holding in DG, it may be quite difficult to replace the DG units with something much thicker, needs careful measurement to see what size DG unit will fit and still allow glazing beads to be fitted, ideally you want the largest spacer bead in the unitthat you can fit, i have in the past had to make custom beads with a rebate so i could get a fixing through the face. the DG unit can be measured with a quite clever device called a glasdickenmesser although i suspect most tradesmen wont have one and will advise removing the glass and measuring it

[Mike]

11 minutes ago, Hobbiniho said:

as said a bit strange to have putty holding in DG

You wouldn't do it these days, but 30+ years ago it wasn't uncommon.

[SteamyTea]

19 hours ago, joe90 said:

20 hours ago, Gone West said:

I thought the oils in the putty reacted with the seal around the edge of the DG unit.

Which is probably why they have fogged

My old ones where puttied in.

Siliconed the new ones in, and they have still blown, except for a couple of them.

I think I know why.

7 hours ago, Hobbiniho said:

glasdickenmesser

Measure frame thickness (a), measure one side to the glass (b) measure other side to the glass (c)

 

a - (b + c) = glass thickness

 

[joe90]

As temperatures rise and fall inside and outside your home, the gas inside the double-glazed unit expands and contracts – putting pressure on the seal. Over time this causes it to weaken and break.
 

this makes sense as in a previous house south facing panels failed over time but north facing ones didn’t??.

[SteamyTea]

6 minutes ago, joe90 said:

As temperatures rise and fall inside and outside your home, the gas inside the double-glazed unit expands and contracts – putting pressure on the seal. Over time this causes it to weaken and break.
 

this makes sense as in a previous house south facing panels failed over time but north facing ones didn’t??.

My experience as well.

Also, the north east facing painted windows 'weather' better than the south west facing ones.  Less UV, rain, salt and windspeed.

[RobLe]

Do the failed wooden DG units have an airspace around the rubber DG seal, which is connected to outside ?  No idea why, but damp near that rubber seal over time causes it to fail.  We’ve got an old wooden front door, used to be single glazed, I upgraded it years ago with DG with an air gap around the DG (just packed the DG up with plastic spacers, and fitted it centrally) and then angled holes drilled to allow low access to low humidity outside air.   Took ages to rout out the frame for the thicker window, then thin wooden beads to finish.  Only wish I’d got better softcoat DG with insulating spacer….. I just bought what was offered at the time, so U perhaps 1.4.

[SteamyTea]

58 minutes ago, RobLe said:

No idea why, but damp near that rubber 

I think that is the case.

The first replacement I did was too small, but is still good.

The rest, I made a bit bigger and they have failed.

The glazing man only offered 1 year warranty on replacement panes if they were going into timber frames.

When I do get around to replacing them, shall go a bit smaller, and have already put in weep holes.

Shall also put in more silicone and accept I will need to scrape off the excess. That bit is easy now as I am not going to be renting the scaffolding. Cornish weather plays havoc with outdoor work timetables.

[joe90]

1 hour ago, RobLe said:

Do the failed wooden DG units have an airspace around the rubber DG seal, which is connected to outside ?  No idea why, but damp near that rubber seal over time causes it to fail.

I have heard that as well, it’s why UPVC has an air gap and drainage (so I am told).

[SteamyTea]

13 minutes ago, joe90 said:

I have heard that as well, it’s why UPVC has an air gap and drainage (so I am told).

Many years ago, I put in a secondary pane of glass into a window.

It misted up in a few weeks.

I then cracked the inner pane during bedroom antics (moving furniture but that is boring).

The misting vanished in now time.

I have often though that a small hole drilled into the inner pane may alleviate this problem.

May get brave and try it out on a blown unit, but only after I have a replacement ready.

[Gone West]

2 hours ago, RobLe said:

Do the failed wooden DG units have an airspace around the rubber DG seal, which is connected to outside ?

I glazed all the DG timber windows in my house in the nineties with hard spacers, Butyl 66 compound and timber beads. None of them failed in the fourteen years we were there.

[Gone West]

This is dredging up memories from the distant past. When I replaced all the windows in that house I painted all the new frames and beads separately with three coats of Sovereign SX70 before glazing them. We drove past that house last year and the same windows were still fitted. I don't know whether any of the DG units had blown but they were 4/6/4 air filled so not that good insulation.

[RobLe]

2 hours ago, SteamyTea said:

I have often thought that a small hole drilled into the inner pane may alleviate this problem.

May get brave and try it out on a blown unit, but only after I have a replacement ready.

It’s definitely the outer pane of glass you should drill, if you want to demist an old DG unit, at least in the UK where we internally heat our homes.      6mm ish diamond drill, the type for tiles might work… good idea to get the spare ready though:-).  It’ll shatter if there’s a kite mark meaning it’s toughened mind.

[zoothorn]

On 09/04/2023 at 09:33, joe90 said:

Which is probably why they have fogged 🤷‍♂️, I don’t see why (like @SteamyTea) you can’t use a timber quarter moulding as long as there is room! And bed them on glazing silicone.

Hi there J90, happy easter to you.

 

This seems plausible theory, as almost every one in their house has failed almost simultaneously, it seems to me.
 

11 x thinner 4-8-4's, (plus 2x 28mm big tall upvc fogged conservatory panes too).

 

I guestimate £3.5k-£4k for a pro doing all 13.. but if I -could- get it figured how one of these 'putty ones' can be done, £2k max in glass & materials me doing it. Glass/ DG unit cost has shot up in a year.

Thanks, Zoot

 

[SteamyTea]

1 hour ago, RobLe said:

It’s definitely the outer pane of glass you should drill,

Meant to say outer, no idea how I got my inniey and out confused.

[SteamyTea]

2 minutes ago, zoothorn said:

£2k max in glass & materials

Last one I did the unit cost about £20.  I think when I did them in 2006, they were £16 each.

Shop around.

[zoothorn]

11 hours ago, SteamyTea said:

My old ones where puttied in.

Siliconed the new ones in, and they have still blown, except for a couple of them.

I think I know why.

Measure frame thickness (a), measure one side to the glass (b) measure other side to the glass (c)

 

a - (b + c) = glass thickness

 

Of course, logical, thanks ST.

 

As to whether it -is- putty.. well, in my very limited knowledge I can't think of any other material it might be.

 

A pic of the bead side.. if it could give any clue:

 

 

[SteamyTea]

4 minutes ago, zoothorn said:

A pic of the bead side.. if it could give any clue:

Try culling into it with a sharp knife.

 

Whoops, did I type culling, meant to say cutting.

Culling it what need to happen to idiots.

Edited April 10, 2023 by SteamyTea

[craig]

1 hour ago, zoothorn said:

Of course, logical, thanks ST.

 

As to whether it -is- putty.. well, in my very limited knowledge I can't think of any other material it might be.

 

A pic of the bead side.. if it could give any clue:

 

 

That’s putty, just been painted over.