spencerd
Active Member
Can anyone suggest where to purchase new rubber seals for portlights as mine are leaking slightly? Lewmar want £35 per seal .......robbers.
Lewmar portlight seals for bav 44 2003 model
- Thread starter spencerd
- Start date
ostra4
Well-Known Member
Have a look at seals direct ,massive selection -
jdc
Well-Known Member
All Lewmar hatches leak after a bit: on my 2005 boat when we get green water over the decks, a bit comes through the closed hatches whatever we do. We have replaced the rubber seals on some hatches, and it makes little difference. I've seen this on all boats I've been on.
The reason is that Lewmar hatches are shockingly unfit for their purpose in my opinion. They may be, I suppose, fit for the purpose of a boat builder fobbing off the purchaser with something which looks good and will last a couple of seasons, but for serious long term cruising they are less suitable because they always leak. It's because the seal is by direct compression of a rubber strip by direct force, ie the harder the hatch is pulled down the more the rubber is compressed, and this is always a recipe for poor performance.
O ring seals work differently:
1. Their compression is an exact and optimum amount determined by the dimensions of the groove in which they sit
2. Once there is a metal-metal contact no further force will compress the seal further, nor would it be useful, and
3. O rings in a groove are easily replaced, so if the seal is damaged it's not a problem. (The rubber seals on Lewmar hatches are awful or indeed impossible to replace - even they advocate trimming off the lip with a knife as it's impossible to get back in the groove: proper job eh? - not)
Unfortunately, while engineering a better hatch would be trivial design task, it would have to be constructed to finer tolerance than possible from cheap welded Aluminium extrusions, and would also have to be stiffer, ie made of thicker section. These might add a small extra cost, but we're simply not given the choice of paying more for better quality.
The reason is that Lewmar hatches are shockingly unfit for their purpose in my opinion. They may be, I suppose, fit for the purpose of a boat builder fobbing off the purchaser with something which looks good and will last a couple of seasons, but for serious long term cruising they are less suitable because they always leak. It's because the seal is by direct compression of a rubber strip by direct force, ie the harder the hatch is pulled down the more the rubber is compressed, and this is always a recipe for poor performance.
O ring seals work differently:
1. Their compression is an exact and optimum amount determined by the dimensions of the groove in which they sit
2. Once there is a metal-metal contact no further force will compress the seal further, nor would it be useful, and
3. O rings in a groove are easily replaced, so if the seal is damaged it's not a problem. (The rubber seals on Lewmar hatches are awful or indeed impossible to replace - even they advocate trimming off the lip with a knife as it's impossible to get back in the groove: proper job eh? - not)
Unfortunately, while engineering a better hatch would be trivial design task, it would have to be constructed to finer tolerance than possible from cheap welded Aluminium extrusions, and would also have to be stiffer, ie made of thicker section. These might add a small extra cost, but we're simply not given the choice of paying more for better quality.
Just_sayin'
Well-Known Member
I thought that I had paid for quality on two of my previous boats.
http://www.hallberg-rassy.com/hr43/HR43-speci.shtml
http://www.hr-parts.com/contents/en-us/d264.html
According to you I didn't.
Appalled of Lymington
Cloven
Well-Known Member
I have just replaced 2 of these Portlight seals using the genuine Lewmar ones. Yes, they are expensive but they do come exactly the right size & with fitting instructions etc. if you can get the correct seal profile then you would have to calculate the correct length and then somehow join the ends together to make a complete seal.
As for fitting, the seal is bedded in a glazing grade silicone sealant. The secret is to remove every scrap of the old sealant before trying to fit the new seal. I reckon it too me over an hour of painstaking work on each one to get the old sealant out. The edge of the new seal has an arrow shape appendage and this is inserted into the cleaned out groove after the groove has been filled with fresh silicone. Unless you can get a replacement seal with this arrow shaped appendage, then I can't see how you could ever get a good seal.
Good luck.
RichardS
N/A
This is true but I have found that if you occasionally clean up the alloy beading with white spirit and then well lubricate the rubber with silicon grease or red rubber grease they do seal well for a year or two. The advantage with the bright red grease is that you can close and open the hantch and easily see if there is a gap.
Richard
john_morris_uk
Well-Known Member
That's odd. I started replacing all the hatches and opening lights with Lewmar products on our boat ten years ago. None of them have started leaking yet. Should I be worried?