How accurate does one have to be when measuring Gray Enterprises portlights for replacement?

[limbodog]

I'm intimidated by this job, because I'm worried I'll get the old one off and the new one won't fit and then I'll be trying to scramble to find one that fits and get it delivered while my portlight is wide open, it's going to get colder, and the vampires can get in.

So yeah, I have a 1985 Hunter 40. They were made using Gray Enterprises portlights. (you probably knew this)

The website says to measure the outside of the lens from side to side to determine its size. https://shop.sailboatowners.com/gray.php
I did so, and I get 14 and 13/16ths inches (possibly 7/8ths of an inch)

When I look up the sizes (also on the above link) I see "414" which is Lens dimensions 14-1/2 inch which is smaller, or "715" Lens dimensions 15-5/8 inch which is larger.

The size "715" goes into 8ths of an inch (others go to the 16th), so it's not like the 14 1/2 inch was just a rough estimate. I'm also assuming that they get down to the 16ths because they don't allow much wiggle room.

But having never done this, does that mean I need to buy a larger size and dremel the openings to fit a 15 5/8ths " portlight? Or can I buy one that is slightly smaller by 5/16ths of an inch and it won't have a gap through which the vampires can get in?

Or should I switch brands to one that will fit without having to do fiberglass surgery?

 

[dlochner]

The lens, the part of the port you see through is 14 ½" the extra is frame. I say this without having seen this particular port up close and personal. To be certain, call the SBO store and talk to Al, he'll know. Be a bit patient, SBO is a very small company and has few employees doing all the work.

 

[kloudie1]

I happen to have a 512 here.. Measuring the lens itself, it is 5 3/4" wide and 12 11/16 long
The 414 lens measures 4 5/8" wide and 14 9/16" long.. My '85 H-34 has 6 of the 512's and three of the 414's.
Looks like you have the one I don't have.

 

[Stu Jackson]

Or should I switch brands to one that will fit without having to do fiberglass surgery?

If you are definitely sure they are Grey portlights then do not change brands.

Look, it is a lot simpler than you are making it. Any and all companies that make portlights (Grey, Lewmar, Beckson, etc.) make a small handful of sizes. That's all, nothing in between. Each of their websites explains how to measure their own portlights, so you can confidently order replacements.

I had exactly the issue you have, but it was 27 years ago, before the internet. I got on the telephone (remember that tool?!? ) and called my manufacturer, Beckson, and asked them. They explained it and mailed me their brochure, sizing manuals and installation guide, which arrived a few days later. I read it and realized that I was making a simple task much harder than it really was. You already have all that info.

Good luck, you'll figure it out.

 

[Allan12210]

My 1985 34 of the same vintage as yours also came with the Gray Enterprises Portlights. They were the same size as @kloudie1 has described. I decided to upgrade mine to the Beckson. The openings cut into the cabin top had a bit of margin, but not a lot. The flanges on both sides cover the holes. It took a bit more effort than I expected. Be patient. I did have some water intrusion on a couple that required me to dig out the rotten plywood core material and fill it with thickened epoxy. Also I discovered that the inner liner was not adhered to the plywood core. That was only bonded to the exterior skin. I chose to fill that gap with pieces of cedar shims (available at Home Depot) saturated in epoxy. Then I coated the plywood edge of the cut with more epoxy. Also, the rain drains were in slightly different places so I had to fill the old cut outs and cut new ones. You may have to trim the extension for an even reveal to what you already have. I used an oscillating multi tool with a block of wood for the proper distance. Maybe these pictures can help a little. Good luck.

 

[limbodog]

Mine don't have drains at all. Or, rather, they drain into the interior all the way back in my rear cabin via a nice long aqueduct built for the purpose of making sure the captain knows its raining while he or she is sleeping. So it sounds like some fiberglass surgery is in order no matter what it looks like. Good to know.
I'll give the AI a chat (all hail our future overlords) to clarify, but then I guess it's time to pull the trigger
Thanks everyone!

 

[Stu Jackson]

ld, FYI, the drains Alan mentioned are called "Rain Drain" on Beckson ports. https://beckson.com/opening.html

The drain is built into the bottom half of the port and, IIRC, doesn't require any gouging of the fiberglass deck/hull at all, it is still a rectangular opening. Or, if it does have some glass removed for the drain on the port it would have been there already and ready for a simple "for like" replacement. Just as Alan's pictures show.

I do not know if Grey makes a rain drain type opening port.

That said, I do not understand your mention of "fiberglass surgery" at all. If you find the right size replacement you shouldn't have to touch the fiberglass at all.

I have eight 5x12 Beckson ports on my boat and have replaced four or five of them in the last 28 years. Didn't need to touch the fiberglass at all.

Please help us understand why you think you need to do so.

Mine don't have drains at all. Or, rather, they drain into the interior all the way back in my rear cabin via a nice long aqueduct built for the purpose of making sure the captain knows its raining while he or she is sleeping. So it sounds like some fiberglass surgery is in order no matter what it looks like. Good to know.
I'll give the AI a chat (all hail our future overlords) to clarify, but then I guess it's time to pull the trigger
Thanks everyone!

 

[Johnb]

I'm intimidated by this job, because I'm worried I'll get the old one off and the new one won't fit

I suggest you make temporary covers to put on during the job. I made several, as shown in the picture, the cheapest easiest way possible - scrap 0.25" plywood, scrap flooring boards, bulk 0.25" carbon steel bolts nuts and washers, cheap weather stripping on the outside.

This job is pretty much guaranteed to develop hitches when you find water damage or have to do some cutting and fitting. This will allow you to work on more than one at a time and make progress while the glue hardens - takes all the drama out of it.

 

[Dalliance]

They are pretty much like for like replacements. No need to be altering the rough openings. Just follow the manufacturer’s instructions for measuring the existing.
I replaced all of mine around 11 years ago and used the Gray Enterprises portlites from this site. I did switch the quarter berth portlite in the cockpit to Beckson because it has no projecting flanges.
Do use the Dow 795 silicone recommended by the manufacturer. That’s critical. Dow 795 is high grade structural silicone; not bathtub sealant. West Marine doesn’t even know what it is and it wasn’t stocked at Home Depot. I ordered mine from a construction supply company called Mudd Supply. No idea if they’re still around.