GD stamp on bronze portlights

[phorvati]

Does anyone know who made these portlights? Where can I get the gasket material. I would like to get the gasket before tearing it open and letting rain get in while I measure and order the rubber gasket.

[Bowdrie]

I believe they were a Tiawan company, and common equipment on all sorts of Tiawan built boats back in the day.
Your best bet is a replacement made from Buna-N or Neoprene O-ring stock.
All sizes imaginable are obtainable if you know the size, or you can get the stock and glue it together yourself.
Lots of suppliers around, I use this outfit:
Sealsourceinc
Yeah, much talk of "seals" but huge inventory of O-rings and stock.
Probably outfits closer to you.
I've found round stock to be superior to the old square gasket stuff, but square stuff is available if you prefer it.

[Orion Jim]

A picture of the gasket would have been helpful. McMaster-Carr has a large selection and you can buy Bomar gasket material by the foot at Defenders. It has the contact cement already applied, you just peel and stick. Don’t forget to keep the butted ends on the high side and cutting at a 45° is not really necessary where the ends are joined as long as you are liberal with the contact cement at the joint. Bear in mind that an old gasket with an oblong profile started life as a round profile and was pressed into its finished profile after applied and squeezed to its present shape.
Spartan Marine sells replacement gaskets ready to be installed. Check your dimensions, you may just have a size which is the same as a Spartan product.

[phorvati]

Originally Posted by Orion Jim

A picture of the gasket would have been helpful. McMaster-Carr has a large selection and you can buy Bomar gasket material by the foot at Defenders. It has the contact cement already applied, you just peel and stick. Don’t forget to keep the butted ends on the high side and cutting at a 45° is not really necessary where the ends are joined as long as you are liberal with the contact cement at the joint. Bear in mind that an old gasket with an oblong profile started life as a round profile and was pressed into its finished profile after applied and squeezed to its present shape.
Spartan Marine sells replacement gaskets ready to be installed. Check your dimensions, you may just have a size which is the same as a Spartan product.

So I dont know my size. I need to take the gasket out to measure because the groove seems very deep and the gasket is spilling out. I'm going to wait and hopefully someone who has done this can give few pointers.