top of page

Window & Portlight refurbishment - fixed pane units

Fixed pane units typically feature a two part frame with at least one channel within which the pane is sealed.  Typically the seal is created from sealant applied to each side of the pane during manufacture, but it may also be a preformed rubber seal , glazing tape or a combination.  Panes are commonly Acrylic, 5-8mm thick, more often clear than tinted, but may also be toughened (heat tempered) glass and thinner.


The first thing to consider is that other than catalogue frames from major manufacturers (eg Lewmar), most windows are boat/model specific and given their likely age, made by companies that have long since disappeared.  So often, this is bespoke work for us and explains why we ask so many questions and seek photos prior to quoting. 


We can only work on units which can be dismantled, so a key consideration is identifying the number and location of so called 'split' lines.  Each unit typically has two, though some (eg N C Bjerg units) may only have one.  They are often found at the mid-points (vertical or horizontal) of units with radius corners, or at the mitred corners for units with hard corners.  Frame sides are typically held together with strips of alloy, called fishplates, which are screwed in position.  These are often drilled and tapped in position so please remember to only release one side if tempted, as otherwise you'll have a handful of fishplates and the puzzle of which goes where!


We now use advanced specialist silicone sealants, allied with the highest quality cast sheet materials to ensure windows outlast your custodianship.  Perspex carries a 10 year guarantee (from the manufacturer, subject to conditions) and we are confident that properly applied, the silicone sealant will last many times longer than traditional butyl based Marine Seal 033 with which most windows would have been originally sealed.

We provide guidance on how to remove and refit fixed windows and portlights in our Blog.

If your windows have been installed with the correct bedding compound, removal should be straight forward.  If they were (re)installed with Sikaflex, bathoom sealant (yes, really) or a similar adhesive, good luck getting them out (without bending the frames)!


Process - what we do best

Our outline process is as follows;

  • On receipt, the window is assessed and inspected. If any damage or severe corrosion is noted, we will contact the customer.

  • Split lines are checked and fishplates released to facilitate dismantling.  

  • The frame is dismantled and glazing removed.  All parts are labelled.

  • If toughened glass, the glazing is checked to ensure it can be reused.  If faults are found, the customer is given the option to have a new panel cut and heat tempered, or replaced with plastic.

  • The frames channels are thoroughly cleaned.  This is particularly time consuming, but necessary for long term adhesion.  

  • The cleaned channels are abraded to ensure a sound bond prior to being treated with an appropriate specialist primer.

  • Where new plastic glazing is required, this is cut and/or machined to shape and edges finished.

  • The window glazing is treated with another appropriate specialist primer.

  • The glazing is positioned within the frame/channel with chocking rubber when appropriate, to ensure an even void ready for sealant.

  • The complete window is re-assembled and joints are sealed.  If new fishplates are needed these are manufactured and fitted.

  • The glazing is re-sealed with a pressure injected sealant and allowed to cure for at least 48 hours each side.

  • Upon completion the window is inspected and cleaned to remove any traces of sealant on the glazing surface.

  • New plastic glazing is covered in protective film to reduce the risk of damage during re-installation.

  • All windows are carefully packed ready for dispatch/collection.

bottom of page