It's time to try to reseal the windows on my boat again. One of the challenges of boating is the seemingly endless list of maintenance tasks to do. I have perspex windows which are screwed on to the side of the boat. I once attempted to do this task before. The logical thing seemed to be to get a power screw driver, take out the many screws. Clean all of the old sealant off, apply new sealant and screw it back on again (using the power screw driver). I have since learned that I did several things wrong... I found the following useful information at http://www.eagleboatwindows.co.uk/hints.asp;
Fitting a frameless Perspex window
Warning - do not use a powered screwdriver when fitting a Perspex window!
As with the aluminium framed window above, the notes below refer to sealing the window with the non-setting bedding compound as supplied by Eagle Boat Windows which again is recommended for this application.
Check the fit of the window on the side of the boat and check the alignment of the fixing holes. It may help to carry out a "dry" fit of the window using all the fixings to make sure that there are no problems.
To fit the windows, cut the nozzle of the bedding compound at 45°, and apply a 6mm/¼" bead of bedding compound in line with the screw holes around the inside of the window that butts against the GRP/wood of your boat.
If your window is not being fitted to a flat surface (e.g. it is fitted to the side of your boat), then it may be helpful to insert a small plain stainless steel washer between the Perspex and your boat at each screw position. This will ensure that the thickness bedding compound is even over the whole length of the window and that there will be little or no migration of bedding compound in the middle area of the window.
Present the window to the aperture (remember orientation!) and press it against the boat. You will see a witness of bedding compound appear in the holes where the screws locate and this must be removed. Insert the screws and tighten very lightly around the window. Working your way around the window several times, tighten the screws so that there is an even gap of about 1 to 2mm between the Perspex and the boat. Always be aware of the torque you are applying to the screw and watch for any bowing of the window between the screws.
Leave the witness of bedding compound to harden for a few days and then, using the small plastic scraper supplied, peel off the excess compound. If there are any stubborn remnants of material, use a soft cloth and White Spirit to remove it.