I had several small leaks on my side windows and during lockdown I took the advice from earlier forum posts and reseated all the retaining screws with butyl .
This seems to have worked with the exception of one of the port hand windows. On inspection the retaining screws do not seem to be pulling the window tight to the seal and they won't tighten any further.
What do the screws, which look like self tappers bite into ? Is it the fibreglass or do they go through to the internal window surround ?
If its the window surround I was wondering should I change the self tappers to bolts (like those on the deck windows) so that they can be pulled up tight to make the seal.
Your advice as usual will be most appreciated.
ASHANTI is now out of the water on the trailer in the yard of Medway Cruising Club and from the cockpit I now have a most amazing view down the Medway towards Sheerness. I'll take a picture next time I'm at the boat and post it.
The screws are not there to compress the window to the fibreglass only to provide mechanical location - if you replace them with bolts you will almost certainly overtighten them and crack the window and it wont seal the leak. The only proper solution is to remove the window and replace the sealant with the proper sealant that bonds to both perspex and fibreglass. Most general purpose sealants won't work long term and are only short term fixes. The proper sealant to use is Sika Sikaflex 291i Marine Sealant which is a marine grade PU sealant specifically for this application silicones and butyl general purpose sealants are not the correct product to use. I did the deck window on our 26M and it was both easy and made the seal permanent. The screws are into the fibreglass and don't need to be very tight to seal properly once the sealant is in place. The old sealant can UV degrade with time and then you get capillary tracks which no amount of tightening will solve. The old sealant can be removed with a craft knife and some white spirit to give aclean surface to reseal but DO NOT use acetone as that will dispoolve both the sealant and the window! There are some on line application documents for marine sealants on the Sika website.
Over the years I've used a lot of sealants and attempted boat leak repairs without removing and replacing - they all fail, mostly very quickly! The modern PU sealants are superb, they stay elastic, are salt water resistant and UV protected.
Hope this helps.
Mike C
Hi Mike
Your advice is brilliant as usual
I'm pretty sure that I have a tube of the Sika 291i that I bought when replacing the deck windows so I'll give it a go with that
Many thanks