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toddster

Taiwanese Opening Portlight Install

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One of those "bargains" that I picked up a few months ago at the marine exchange - nice unused stainless opening port that I thought was just the thing to bring some light and air into the quarter berth - from the cockpit footwell.  So, today I was rebedding another port and figured it was about time to install that thing that's been bouncing around in the project locker for months.

:unsure:

So I found out why this shiny new thing was in the bargain bin.  WTF?  The flange and seal is on the inside?  The (outer) trim ring holes don't line up with the inner flange?  A bit of searching on line and I came up with this, which is pretty close:

51YgJ+-aUML.jpg

 

41nnc1Yd9oL.jpg

So this thing is intended to go into a solid wood structure at least an inch thick  with wood screws... What I have is two layers of fiberglass; the quarter berth liner and the cockpit tub, that just sort of float next to one another, maybe total 1/2 inch thick in total.  

OK, I could put a wood filler on one side or the other (probably outside) and proceed as shown at the left.  But I'm sort of inclined to ditch the outer trim ring and fabricate one that fully lines up with the inner flange and through-bolt them together, caulking the snot out of it.  Hmm... I guess I'd still need the trim ring to conceal the caulk line. Or I could try to "self-tap" short machine screws into the fiberglass.  That would probably hold "for a while." 

Anybody succeeded (or failed) at installing one of these things in fiberglass?

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Instead of bodging it get a machine shop to mill the spigot - the "flange" that goes through the cabin side - to the depth you need.

Bolt it though the outer trim ring - fastener heads on the outside and nuts on the inside..

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The bolts you want for this are called barrel bolts, beckson(portlight) manufacturer sells them. Much wider range of tightness vs acorn nuts. 

 

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Thanks but as stated above, through-bolting to the existing trim ring is not possible.  The flange and the trim ring are not the same size and have different bolt patterns.  Moreover, due to the angle of the "spigot" they end up being offset.  They are just close enough that through bolts to either will interfere with the other.  Something will have to be cobbled together.  Which I certainly can do.  Whether it will A. Not leak B. hold up to a potential cockpit full of water pushing on the wrong side. and C. not look like shit, remains to be seen.  

 

IMG_2033.jpg

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7 minutes ago, toddster said:

Thanks but as stated above, through-bolting to the existing trim ring is not possible.  The flange and the trim ring are not the same size and have different bolt patterns.  Moreover, due to the angle of the "spigot" they end up being offset.  They are just close enough that through bolts to either will interfere with the other.  Something will have to be cobbled together.  Which I certainly can do.  Whether it will A. Not leak B. hold up to a potential cockpit full of water pushing on the wrong side. and C. not look like shit, remains to be seen.  

 

IMG_2033.jpg

You'll still need to solve the trim ring problem.  Easiest would probably be to take it to a CNC shop and have them make you a new plastic one with no holes.  Line it up, drill your own and install.  While that's happening get a bag of barrel bolts. 

 

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or if you're going to make a new outer ring anyway, make it like the newfound metal ones with sockets that match the bolt holes in the port.then you can screw through into a socket that doesn't penetrate the outer trim ring, getting rid of at least a few places where it can leak.

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My fibreglass boat has 8 similar portlights installed in the hull. Great big bronze things. The outside flange on them does line up so they install by bolting through. The three months I've spent replacing the wood trim of the salon of the boat is testament to how stupid it is to seal the portlights from the inside once the sealing give way.

But I digress; here's an alternative idea, if you have the room. The portlights are thick anyway, so install a teak or synthetic frame on the inside of the cabin. With sufficient thickness you can screw your screws into the combined fibreglass/wood just as if it were a wood boat. You can use a good polysulfide sealant/adhesive (but not that adhesive it can never, ever be disassembled again!) to seal everything up. When I rebedded my portlights, I used  a bead of butyl tape around the frame as well so that it would compress and fill the void between the cutout and the portlight on insertion.

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