Bedding new front door glass.

[Slim]

After 20 years + the double glazing panels in my wooden front doors have failed and needed replacing. In the end I decided to bring them home and work on them on a bench. Much easier!

 

The frames are made of African Mahogany and apart from some glue failure in perfect condition with absolutely no rot or decay. The glass fits into internal rebates and is secured with beading. I was convinced that I had bedded the glass in silicone but when I removed it discovered it was in putty.

 

My question is, Which is better Silicone or putty? What have others used and how has it stood up to the ravages of time ?

 

Any suggestions welcomed. many thanks

 

 

Frank 

 

 

.  

[Boater Sam]

48 minutes ago, Slim said:

After 20 years + the double glazing panels in my wooden front doors have failed and needed replacing. In the end I decided to bring them home and work on them on a bench. Much easier!

 

The frames are made of African Mahogany and apart from some glue failure in perfect condition with absolutely no rot or decay. The glass fits into internal rebates and is secured with beading. I was convinced that I had bedded the glass in silicone but when I removed it discovered it was in putty.

 

My question is, Which is better Silicone or putty? What have others used and how has it stood up to the ravages of time ?

 

Any suggestions welcomed. many thanks

 

 

Frank 

 

 

.  

DG units are not guaranteed when fitted to wooden frames I found.

The oil in putty degrades the silicon that they are sealed with.

I now fit glass in boats with closed cell foam sealing tape         ( Like,   https://www.screwfix.com/p/diall-sealing-strip-brown-24m/533fr)  )    on the outside and dry fit interior beads with maybe a smear of silicon to stop any condensation getting into the rebate.

20 years, you have done very well, they must of been excellent quality units.

My frames are Honduras Mahogany, 30 years old and no rot either.

[WotEver]

When I replaced some units on our Sapele conservatory I used a non-setting brown mastic which has proved to be 100% water-tight and allows the wood to move without disturbing the units’ seals. I contacted a local sealant specialist and asked their advice. I had to buy a box of 12 tubes but it seems to keep very well. 

[Bee]

I have used mastic type goo and its messy and as Boater Sam says its not recommended by people who know. Another vote for foam strip.

[WotEver]

7 minutes ago, Bee said:

I have used mastic type goo and its messy and as Boater Sam says its not recommended by people who know. Another vote for foam strip.

I agree that it’s messy but as for ‘the people who know’ I went straight to the ‘horse’s mouth’ and bought on their recommendation. I suppose, as a sealant manufacturer, they were bound to recommend one of their sealants but whatever, it’s proved 100% effective for over 2 years so far. Closed cell foam would certainly be less messy. 

[Boater Sam]

I need to clarify before there is another misunderstanding.

 

When we bought double glazed units, the guarantee was invalid if fitted to wooden frames. This is because the makers prefer them fitted in upvc frames with spacers and loose beads so that there is a water drain to protect the edge seal which is silicone.

Putty or the oil in it destroys the silicone, turning it to "cheese" which causes condensation in the pane.

Whether this applies to any or all mastic products, which I believe to be oil based, I do not know.

Silicone is a safer option but is very messy to use for this purpose, it squeezes out when the glass is bedded in and again when the beads are fitted. It is difficult to remove and cannot be overpainted.

Acrylic sealer is easier as it can be cleaned up with water before it is cured. It can be overpainted.

I have had success with glazing tapes but they must be closed cell so that they do not absorb water.

[WotEver]

1 hour ago, Boater Sam said:

I need to clarify before there is another misunderstanding.

 

When we bought double glazed units, the guarantee was invalid if fitted to wooden frames. This is because the makers prefer them fitted in upvc frames with spacers and loose beads so that there is a water drain to protect the edge seal which is silicone.

Putty or the oil in it destroys the silicone, turning it to "cheese" which causes condensation in the pane.

Whether this applies to any or all mastic products, which I believe to be oil based, I do not know.

Silicone is a safer option but is very messy to use for this purpose, it squeezes out when the glass is bedded in and again when the beads are fitted. It is difficult to remove and cannot be overpainted.

Acrylic sealer is easier as it can be cleaned up with water before it is cured. It can be overpainted.

I have had success with glazing tapes but they must be closed cell so that they do not absorb water.

I don’t fundamentally disagree with any of this. The ‘goo’ which I used was exceedingly messy and was cleaned up with white spirit. It doesn’t appear to have had any adverse effect on the sealed units as, two years on, none have failed. The wooden frames have built-in drainage just like a UPVC frame but being wood they obviously move a lot more than UPVC.

 

Personally I steer clear of anything which contains silicone near anything which might have to be painted or varnished in the future. 

 

The next time I bed some DG units I’ll definitely try closed cell foam as it will patently be much less messy. 

 

Oh, and the sealed edges on the DG units I bought definitely didn’t ‘feel’ like silicone. It was much more like a setting mastic in appearance and feel. 

[Slim]

Thanks for the replies.

, As I recall the wood I used was the very best available from a really good, old fashioned, timber yard. {long gone}. The glue was 2 pack West Epoxy with fine filler added. The joints are all M & T and fitted perfectly. Took ages and I was really chuffed. 

What you said about DG units doesn't surprise me. The original are fairly thin, maybe 5mm air gap, and the frames won't accommodate currently available units. I've decided to go for single glazed, toughened instead. I doubt I will see much difference. Hadn't even thought of closed cell foam (and there's a large roll of it on the boat}. My only reservation is that although I've been extremely careful removing the putty I have  caused very minor damage that silicone/putty would better cope with. Also I've only removed the putty from one door so far. I'll see how I get on after lunch with the other door. Whatever I use I intend to glue up and paint thoroughly before fitting the glass. 

I'll come back when I've finished to update.

[WotEver]

1 hour ago, Slim said:

The original are fairly thin, maybe 5mm air gap, and the frames won't accommodate currently available units.

If you approach a DG manufacturer (as opposed to reseller or DG ‘company’) they will fit whatever spacer you specify. I had some built with a 6mm spacer bar a few years back for a Dog Box build. 

[stegra]

I've worked in the double glazing trade since the '80s. We were always told to use butyl putty in wooden frames:

 

https://www.ebay.co.uk/itm/Everbuild-Butyl-Glazing-Compound-Putty-Window-Frames-Double-Glazing-BROWN-2kg/112259351327?epid=1704321545&hash=item1a232dc31f:g:aFkAAOSwQcJaEpON

[Boater Sam]

10 minutes ago, stegra said:

I've worked in the double glazing trade since the '80s. We were always told to use butyl putty in wooden frames:

 

https://www.ebay.co.uk/itm/Everbuild-Butyl-Glazing-Compound-Putty-Window-Frames-Double-Glazing-BROWN-2kg/112259351327?epid=1704321545&hash=item1a232dc31f:g:aFkAAOSwQcJaEpON

I tried Butyl putty on the recommendation of a DG manufacturer, they still refused a warranty with timber frames.

It was horrible stuff to use, not sticky enough. The old hands who were used to linseed putty and in the habit of spitting on their hands to stop it sticking whilst rolling it up found that it affected the butyl, making it break up and not sticky at all!

It was very difficult to tool to a chamfered bead outside too.

 

As an aside we were doing house renovations and on one site the kitchen window needed repointing with putty every morning. We thought the local lads were nicking the putty and went around offering them some free if they would leave the window alone. We thought this kinder than mixing broken glass in with the putty, standard anti vandal measure.

An old guy who lived opposite came over one morning whilst we were repointing the window yet again. He remarked that he watched the birds eating the putty every morning. Turned out the putty was made with fish oil instead of linseed.