...remove the failed unit from the window
STEP 1 - Remove the unit from the frame
Because I fitted my sealed units myself I
already knew how to remove the glass from the frame. On my
timber windows the units are externally beaded and are
removed from the outside (easier said than done however so
there was a bit of work needed).
Frames can be beaded on the inside or outside
- and if you wish to try this type of DIY repair you will
need to find out how to remove your unit without damaging
either the unit or the frame. Given the wide range of
possible frame designs I can't help much with this step I'm
afraid - you'll need to work this out for yourself.
I also knew beforehand what the basic
construction of the units was. If you can it is wise to
inspect the unit whilst it is still in the frame to check
the construction. Check that the spacer frame has separate
plastic corner pieces that can be removed to allow the
desiccant to be removed and replaced.
You may wish to wear gloves when handling the
glass - it depends on how sharp the glass edges are.
Normally the manufacturer will have removed all the sharp
edges to allow trouble-free handling, but you can't be sure
so take care handling the panes.
....lay the unit on a solid workbench...
STEP 2 - Set up a good working space and
support the unit.
If you are working on a floor surface you
don't want to mess up put down a sheet before you setup.
The newly removed sealed unit will need to be
supported on a solid work surface, and you will need good
access all the way around the unit as you will be working
along its edges.
I used a workmate bench with an old towel
laid on the top on which to lay the glass. This reduced the
possibility of damage to the glass surface, and provided a
good solid support. Helpfully the glass also overhung the
edge of the support - good for handling and later when
re-sealing the unit.
STEP 3 - Clean-up and open-up the sealed unit.
With a sharp Stanley knife (or
similar) remove any sealant or putty from the top surface of
the top pane.
Clean the top glass surface - I found it best
to clean the surface presented at each stage so that dirt
was not transferred from one surface to another as the work
...clean the top pane...
...cut the sealant under the top pane....
Then, again with a sharp Stanley knife, cut
through the edge sealant against the underside of the top
pane of glass. I found it best not to attempt this as one
deep cut but to take a number of shallow cuts - first
through the sealant and then carefully through any adhesive
bonding the spacer bar to the glass.
On my units the spacer was only lightly
bonded to the glass - the main bond holding the unit
together was the sealant to glass bond.
Remember you are working with glass that is
brittle - don't force anything, or you'll end up breaking
the pane. Remember - make sure the blade you are using is sharp.
...remove the top pane...
Cut along all four sides of the top pane - ie
right around the sealed unit to allow the top pane of glass
to be lifted off.
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