Mealting black seal inside double glazed unit. Post questions and find answers on glazing, double glazing, upvc glazing, conservatory glazing, fixtures and fittings etc....

[carpenter]

We have installed new double glazed units in timber windows approximately twelve months ago. We now find that the black bitumine inner seal is melting in blobs on some of the units, could you please tell me if you have come accross this problem before and tell me what may have caused this to happen.

[stoneyboy]

carpenter,
If you used putty to seal in the windows then the solvents in the putty are dissolving the glazing sealant.
end

[carpenter]

stonyboy,

Arborsealtape and a nuteral cure silicone was used to fit the units in the timber windows.

[carpenter]

carpenter,
If you used putty to seal in the windows then the solvents in the putty are dissolving the glazing sealant.
end

Arborseal tape and a nuteral cure silicone was used to fit the units into the windows.

[stoneyboy]

carpenter,
In that case the units are faulty - get the supplier in to have a look. DGUs in timber windows generally have a 5 year guarantee.
end

[trond]

Google "tremco-illbruck.co.uk/celumdb/documents/Sealant_Compatibility_Bulletin_GB_10437.pdf"

Have a read of this.It's a useful and detailed document on the subject.

It's not a unit fault at all, but a silicone issue. 'neutral cure' or seeing the use of 'glazing' on it isn't a rubber stamp of suitability.. There's so many silicones now full of additives, fillers, anti-fungals etc that cause real damage to DGU's up and down the country.

[gemmadoc]

Hi. I was wondering did you ever resolve the issue of your melting seal in the units. I am having the exact same problem at the minute.