Replacing seal on Lewmar portlight

[daibachsail]

We have the original 2004 portlights and they seem to be signs of leaking. Would you expect them to last longer? Is there a way of improving their 'leakproofness' without replacing them?
Thanks

 

[Quandary]

Treat the rubber seals with a light smear of vaseline from time to time. A lot of Lewmar portlight leaks are actually at the rubber/ plastic fishtail joint in the outer frame, if it looks intact and flush with the metal on the outside try Cpn. Tolley. (be sure to completely remove any run off immediately). If they have shrunk and moved use a stiff sealant like Arbosil tooled in from the outside after carefull masking around the joint.

 

[dje67]

Treat the rubber seals with a light smear of vaseline from time to time. A lot of Lewmar portlight leaks are actually at the rubber/ plastic fishtail joint in the outer frame, if it looks intact and flush with the metal on the outside try Cpn. Tolley. (be sure to completely remove any run off immediately). If they have shrunk and moved use a stiff sealant like Arbosil tooled in from the outside after carefull masking around the joint.

I had several leaks which were from the 2 seals that join the upper and lower halves of the frame. Used CT1 to replace the seal and had no leaks since. Mine might be a different vintage; newer frames only have a single seal, but might suffer the same issue.

 

[goeasy123]

They're cheap and easy to replace. See here.... LEWMAR Standard Portlight replacement Seal For Old & New Standard Portlights | eBay

 

[daibachsail]

They're cheap and easy to replace. See here.... LEWMAR Standard Portlight replacement Seal For Old & New Standard Portlights | eBay

Thanks
Yes I have already purchased a metre of that to try out on one window. However it doesn't look that easy and it seems very early in a seals life to need replacement. I also wondered about using vaseline or similar.

 

[daibachsail]

Treat the rubber seals with a light smear of vaseline from time to time. A lot of Lewmar portlight leaks are actually at the rubber/ plastic fishtail joint in the outer frame, if it looks intact and flush with the metal on the outside try Cpn. Tolley. (be sure to completely remove any run off immediately). If they have shrunk and moved use a stiff sealant like Arbosil tooled in from the outside after carefull masking around the joint.

I used to use a smear of vaseline on previous boat windows but was challenged as to whether it is OK on the Lewmar seals. Are you sure that it is OK? It doesn't degrade the seal?
Thanks

 

[goeasy123]

I use 3 in 1 silicone spray. Spray it into the cap and swipe it on with your finger.

I'm told that vaseline, being in the same chemical family as the seal material, may degrade it. Silicone is a safe bet at it's pretty inert.

 

[Plum]

I used to use a smear of vaseline on previous boat windows but was challenged as to whether it is OK on the Lewmar seals. Are you sure that it is OK? It doesn't degrade the seal?
Thanks

My Lewmar portlight/hatch seals are 20 years old and for the last 5 1/2 years have been applying vaseline with no ill effect.

www.solocoastalsailing.co.uk

 

[Quandary]

All the reports I have read on replacing the rubber seal on portlights seem to suggest that 1. it is quite difficult and 2, it is rarely necessary.

 

[Bobc]

1./ DO NOT use Vaseline. It is petroleum based and will harden the rubber and make the problem worse. The only stuff you should be wiping on the seal is silicone grease.

2./ DO NOT use CT1 to re-seal or re-bed portlights as you will NEVER get them out again. Always use Butyl.

3./ New seals are reasonably cheap and easy to fit, but it may not be the seals that are gone. It could be that the lenses are deformed from the constant pressure of the opening clamps.

 

[daibachsail]

All the reports I have read on replacing the rubber seal on portlights seem to suggest that 1. it is quite difficult and 2, it is rarely necessary.

This is very much what I suspected. Where did you find such evidence?

 

[dje67]

In my case, of the 13 port-lights on my 36cc, none of the leaks I had were from the rubber 'cylindrical' seal that the window seals/presses against. Nor were any from the gasket between the frame and hull. All (3 of them) were from the small inserts between the aluminium frame sections. All fixed by removing the insert and injecting a small 'strip' of CT1 into the gap. I don't see this being a problem in the future as the CT1 is not performing any sticking/glue function and could easily be removed in the future. CT1 seems to be pretty UV resistant (so far) and the light grey CT1 is a good colour match for the extracted insert. If you end up replacing the 'cylindrical' seal, or re-bedding the frames, I wouldn't use CT1 - too powerful.

So, not a huge evidence base, but just my observation from a sample of 13 portlights which have now been leak-free for around 5 years so far....

 

[daibachsail]

In my case, of the 13 port-lights on my 36cc, none of the leaks I had were from the rubber 'cylindrical' seal that the window seals/presses against. Nor were any from the gasket between the frame and hull. All (3 of them) were from the small inserts between the aluminium frame sections. All fixed by removing the insert and injecting a small 'strip' of CT1 into the gap. I don't see this being a problem in the future as the CT1 is not performing any sticking/glue function and could easily be removed in the future. CT1 seems to be pretty UV resistant (so far) and the light grey CT1 is a good colour match for the extracted insert. If you end up replacing the 'cylindrical' seal, or re-bedding the frames, I wouldn't use CT1 - too powerful.

So, not a huge evidence base, but just my observation from a sample of 13 portlights which have now been leak-free for around 5 years so far....

Thanks