Head Porthole Rubber Seal Advice

[thompsontwins]

Hello all,

Next on my maintenance/ improvements list:

The previous owner of my LM24 cured a head porthole leak with copious amounts of clear silicone which means I am unable to open it, which I want to rectify.

It seems the rubber or neoprene gasket is perished and I seek advice for a source of a suitable replacement.

I replaced the water tank inspection hatch recently with Amazon/ebay sourced rubber, although the correct size, it was too hard to 'squish' and stop leaks, and needs doing again. The problem with on line shopping you can't inspect your purchase for suitability. I don't want to make the same error, so if anyone has successfully replaced their rubber seals with a suitable product let me know please.

[tonyp]

Hi, I'm not sure which seal is causing your trouble, but I replaced the main seal between the window's inner "ring" fitting and the inside of the hull by cutting a new gasket out of nitrile sheet. It comes in various thicknesses and is relatively easy to cut with a scalpel or Stanley knife. If you take the whole frame off by removing the ring inside the hull Corroded screws will be a pain and will need easing oil and some delicate use of an impact screwdriver. Someone outside holding a weight against the window where you're using the impact driver is helpful.  You can then get the window off and get at the gaskets that seal the window to the grp. A thin bead of silicone on the new nitrile rings you make may help to seal any imperfections.

If the problem is leaking between the opening portlight's gasket and the frame fixed to the grp, you may be able to effect a better repair than silicone by using Scarpa 3507 tape stuck onto the outer surface of the frame against which the opening light seals. This stuff is great because it can be replaced relatively easily and is relatively cheap but very effective. It needs some care in sticking it down to bends and curves, (Hadlow Marine have a useful instruction sheet for doing this - I have no relationship with them) but compresses easily and is used for marine window sealing. It comes in various thicknesses and widths and can be cut to width if necessary, though it can be difficult to get a really neat finish if cutting it down to width. Scissors will work. If you try Scarpa I'd suggest getting more than you need so you can practise. It's important to compress the tape rather than stretch it when going round bends. A thick bit of tape can be compressed to seal, but a thin, stretched bit will never seal. The Hadlow sheet explains better than me!

If the problem is the gasket around the glass, I have no suggestions, I'm afraid, though people like Hadlow and Seals Direct do sell gasket profiles.
Good luck
Tony

[thompsontwins]

Tony,
Thanks for the very informative post. Bit frightening and given me much to consider. I thought it would be less complicated, but then it's a boat....Probably why previous owner went mad with the clear silicone .....
Much appreciated
Paul