Fixing leaking ports

You cannot imagine how gratified I am to see this picture. That is one of BlueJ's port windows after a torrential 3 days of rain, and NO LEAKS. Sadly she has been plagued by leaking windows from the day we got her, and my weak attempts to fix them always seemed to leak again. I finally buckled down and addressed the issue full on, and the result is dry cockpit cushions without the use of buckets!

The first part of any battle is to know your opponent. In our case, the First 260 uses Lewmar OLD Standard Portlights, Size FOUR. The OLD is important, and so is Size Four. Lewmar produced these ports until 1998, so I assume Beneteau would have switched to the (new) Standard Port sometime after that. According to the Beneteau USA Spare Parts site, the cutoff was at Hull # 352. The key differences is in the latch, which does not penetrate the window, and the frame. More on that later.

I discovered that leaks can come from several places, but the primary two reasons are worn or aged ring seals, and a damaged or missing outer frame seal . First up there are two types of ring seals that need to be looked into, latch seals and window seals.

Latch seals are small O-rings that keep water out while still allowing the latch to turn. The old style port uses a hole in the window to allow the latch to pivot, and that must be watertight. That's where the O-ring comes in.

The ring can be seen in this exploded diagram, and is on the outside of the window. Over time, this part wears and grows brittle, allowing leaking. It is important to NOT try and fix this type of leak by simply over-tightening the screw under the cap, as that will just strip the plastic part and probably require its replacement.

The O-ring is a metric size 12mm x 2mm can can be found or ordered from most good technical part suppliers. I got 16 of them for US$1. Clean both the latch part and the window. Use a good waterproof synthetic grease on the rings to help them turn and stay supple.

This might solve the leak, but our ports also needed the main window seal to be replaced. This seal is pressed into the frame and wraps around the entire window. It is exposed to weather and sun (in particular the bottom portion) and has a finite lifespan. The part needed is the Lewmar Old Standard Port size 4 seal, number 19898900. In the USA West Marine sells them for about US$15 each. It is important to get a real Lewmar part, and don't be tempted to use a generic seal that needs to be cut or fitted.

The actual instructions for replacing the seals can be found HERE. I would add some advice:

1) Allow the seal to sit in the sun while you prep the window. Then stretch it a bit to let it come to full size. If it is not allowed to do this, it will be impossible for it to fit and seal correctly.

2) Spend quality time getting ALL the old silicon out of the seal groove.

3) A helper is VERY handy putting the new seal in place.

4) The doc mentions it, but it is very important to make sure you get the correct orientation of the seal! It has a clear inside and outside edge.


Now we come to the outer frame seal, a questionable part of the Lewmar Old port design. My seals were totally missing; if gone your port will look the the picture below, with a clear gap between the top and bottom frame.

If your seals are missing or broken, put a glob of silicon on the small gaps on the seam split on both sides of the inner frame behind the new seal. Do the inside first. There might be a small gray seal here as well, but in my case it shrank slightly and contributed to the leak. This blog HERE does a much better job of explaining this step, and indeed does a better job that I did on the sealant application. Be sure to read if yours are missing.

The end result, no leaks!