Re-bedding a porthole and replacing seal

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Avocet

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I'd be grateful for recommendations as to what to use to re-bed a brass porthole into fibreglass, please. It's not a perfect fit (the side of the coachroof has a slight curve to it, but it's been OK for 30 years! I was going to take it out and re-bad. Also, the opening part of the porthole appears to have some sort of (badly deteriorated) seal too - leather or cork, maybe, can't really see until I get it out)! Any suggestions for what to replace that with? I was wondering about trying to "cast" a ring of silicone in the groove it currently sits in, then waiting for that to set.
 
Avocet said:
I'd be grateful for recommendations as to what to use to re-bed a brass porthole into fibreglass, please. It's not a perfect fit (the side of the coachroof has a slight curve to it, but it's been OK for 30 years! I was going to take it out and re-bad.
Click to expand...

Lifecalk Polysulfide. Stinks but works beautifully and unlike Sikaflex you will be able to remove the porthole in the future, if you need to, without resorting to high explosives.

Also, the opening part of the porthole appears to have some sort of (badly deteriorated) seal too - leather or cork, maybe, can't really see until I get it out)! Any suggestions for what to replace that with? I was wondering about trying to "cast" a ring of silicone in the groove it currently sits in, then waiting for that to set.
Click to expand...

Buy some expanded neoprene cord from Seals Direct (http://www.sealsdirect.co.uk/shopping.asp?intDepartmentId=1#25) and make into a ring with superglue.
 
Thanks both. It's worse than I thought. I've just taken it out and it's nowhere NEAR big enough for the hole in the fibreglass! Some bodging git has found an undersized porthole and he'd made a plywood spacer ring to take up the slop in the hole. That means the outer bezel of the porthole only overlapped the fibreglass by about 1/8" all round! Considering we've had the boat for 20 years, I'm surprised it had sealed as long as it had, to be honest. (Also surprised I'd never noticed)! It also meant, of course, that the ring of bolts (and yes, he'd put ONE mild steel nut on, so all but one came out easily and the last one I had to cut!) didn't pass through the fibreglass. Basically, the whole assembly was free to rotate (other than friction) in the fibreglass.

Anyway, I think I need to try and find a second hand porthole....

Does anybody know how portholes are specified? For example, is a "4" porthole" the diameter of the glass? The outside diameter of the bezel? the hole diameter it fits in?
 
Avocet said:
Thanks both. It's worse than I thought. I've just taken it out and it's nowhere NEAR big enough for the hole in the fibreglass! Some bodging git has found an undersized porthole and he'd made a plywood spacer ring to take up the slop in the hole. That means the outer bezel of the porthole only overlapped the fibreglass by about 1/8" all round! Considering we've had the boat for 20 years, I'm surprised it had sealed as long as it had, to be honest. (Also surprised I'd never noticed)! It also meant, of course, that the ring of bolts (and yes, he'd put ONE mild steel nut on, so all but one came out easily and the last one I had to cut!) didn't pass through the fibreglass. Basically, the whole assembly was free to rotate (other than friction) in the fibreglass.

Anyway, I think I need to try and find a second hand porthole....

Does anybody know how portholes are specified? For example, is a "4" porthole" the diameter of the glass? The outside diameter of the bezel? the hole diameter it fits in?
Click to expand...

Just thinking... could you fill the hole and then re-cut to use existing port hole??? Circle of GRP sheet, epoxied into hole or is the curve too pronounced??
 
Avocet said:
Anyway, I think I need to try and find a second hand porthole....

Does anybody know how portholes are specified? For example, is a "4" porthole" the diameter of the glass? The outside diameter of the bezel? the hole diameter it fits in?
Click to expand...

What's the boat? It may be that a standard sized porthole from something well known will fit - for example, all Westerlies used the same portholes, more or less.
 
Alas, not - fairly obscure boat too, Cutlass 27

Laying up some more glass would be possible (and relatively easy). That's "Option 2" if I can get a dry enough day and a bit of warmth. I'd prefer to a t least see if a bigger porthole could be procured though. It was always pretty dark in that heads / hanging locker area between the forepeak and the main saloon. Also (a bit OCD, this!) having lived with it for 20 years now, the fact that I now know they're different sizes is really annoying me!
 
Ta. Well, good news and bad news... The good news is that their bronze CB0601 looks very similar (if not identical to my "good" one.

...the bad news is that it's gonna set me back £400! It would be cheaper to buy two of their matching brass ones, but I see they're "not recommended for offshore boats". They are CE marked however. Anyone know anything about that? Not that I plan on doing any offshore work in the immediate future, but I wouldn't want to "down-spec" the boat if I could help it. Anybody know any boat breakers I could try?
 
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