DIY double glazing beats condensation
Simon James stops windows from dripping
One of the disadvantages of sleeping or cooking on board in the cold UK climate is that condensation forms on the windows or port holes.
In my case the windows, which were fixed, dripped condensation onto the chart table, bedding and the main cabin upholstery so something had to be done to fix it.
The classic solution in a domestic house is to thermally insulate the windows with double glazing. This adds a layer of insulation which stops heat escaping and raises the surface temperature which, in turn, reduces and hopefully stops the water droplets forming on the glass and window frame surfaces.
So the challenge was to design and make secondary glazing which blended with the interior décor.
The original windows had aluminium frames, which I covered with 3mm thick strips of sticky-back neoprene foam, readily available from chandleries. When attaching the foam make sure the corner joints are completely butted up to form a good seal.
The next step was to make up the mahogany wooden frame. The frame was constructed like a picture frame with a rebate on the inside to accommodate the neoprene foam slightly compressed (10-20%) to form a good seal, plus a 3mm sheet of perspex and silicone bedding compound.
To give the frame a degree of rigidity I used mitred tenon joints and bevelled the edges to match the rest of the wood trim in the cabin.
The attached sketch (left) shows the assembly.
The sequence was to make the wooden frame, assemble it and then do all the varnishing which is easier to do at this stage. The perspex was then ‘glued’ to the frame using a silicone/adhesive sealant. Once the sealant was set the frame was screwed to the window surroundings having first made sure the screws are positioned to avoid hitting the existing window screws.
The wooden frame joints were made by hand, but a router was used to do the rebate and to form the edge chamfers.
Timing the final assembly is important to avoid damp air being trapped between the two panes of glass/perspex. Choose a cold, dry day with low humidity, this will minimise the potential for inter pane condensation forming.
I fitted my double glazing the winter of 2019 and it has made a big difference. I must now tackle the overhead hatches...