Hatches

[Maybritt]

I am replacing my small lewmar deckhouse/cockpit ports which have Al frames with Stainless Steel and twp ply tempered glass. Two reasons. The lexan simply does not stand up to the sunlight longterm it "crackles" very quickly - two/three years - and the Al frames do not stand up well to repeated saltwater washings. Dito my hatches which are EXPENSIVE - Lewmar Oceans. The lexan is already crackling after three years and notwithstanding sunbrella covers which are always in place when alongside/anchored. So I am thinking of going to traditional wooden butterfly hatches with two ply tempered glass and bronze rod which run the lenght of the hatch.

Anyone have any paricuclar thoughts or experience with what I propose or any thoughts they might wish to add ? Thanks. Contibutions to my decision making process most greatfully received.

[Wooden Boat Fittings]

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This sounds like a traditional skylight you're describing, Maybritt. But it's the cockpit hatch? Sliding? A photo would be useful I think.

If it's a one-sided hatch like a forehatch, I'd recommend a study of Maurice Griffith's design for a watertight hatch before proceeding further -- you could make it out of armoured glass, or make it from wood and let a deck prism or a fixed scuttle into it

[Donn]

Here's a lovely hatch design:

http://woodworkingforwatercraft.nstemp.com/PA080884.JPG

http://woodworkingforwatercraft.nstemp.com/PA080891.JPG

More to be found at Woodworking for Watercraft (http://woodworkingforwatercraft.nstemp.com/peakedhatch.html)

[scratch]

In my experience, most production boats use tempered glass. My personal preference would be for safety glass as used in autos. A bit heavier perhaps. Certainly a bit less expensive.

[John Blazy]

Hi Maybritt,
The wrong Lexan was installed initially. Nothing will beat Tempered glass, but if you want to go with something well worth looking into, try Lexan MR-10, a newer product by GE with a full ten-year warranty against yellowing or crazing. The best part is it has a scratch resistant coating. More info here MR-10 topic (http://media5.hypernet.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=006586)

[Ken Hutchins]

Safety glass whether it be just tempered or laminated comes in two qualities, around here they call it safety plate or safety sheet.
The difference between these is safety plate is optically better than safety sheet. Safety plate is required in windshields for better visibility.
Safety sheet can be used in side windows.
Due to less polishing to improve the optical qualities cost more to produce, so I would use safety sheet. Be sure to check with your glass supplier to get the lower quality and price. It cost me dearly to find out the difference.