Lexan thickness for deck hatch

[Alden68]

I see Lexan marketed for use in deck hatch replacement with a thickness of .118". This seems incredibly thin and flismy to to me for a piece of hardware that could be stepped on. Is this the standard based on the strength of the material or am I looking at the wrong product for this application?

[sailingdog]

Alden68-

I guess it depends on how big the hatch is. If the port is 3" x 10", like some of the opening ports you see on boats for ventilation purposes, then that might just be okay. If it is for a 23" x 23" hatch, ummm... you're gonna probably step through it.

Size matters when it comes to deck hatch glazing thickness. The larger the opening, the thicker the glazing needs to be. Of course, some hatches have ribs or bars going across them and can get away with slightly lighter glazing materials, but that's an exception.

[hellosailor]

Alden-
The key word is "marketed". Those guys will try to sell you anything. Like SD says, you've got to run some numbers, the size of the hatch, the loads you expect on it, etc. If the Lexan flexes every time you step on it, it probably will craze eventually. If the purpose is to have the lightest possible hatch glazing that will work for a couple of seasons of racing--it might be fine. If the purpose is to make sure a mast-mounted 20 foot spinnaker pole can't drop through...Maybe not.

[Loewe]

Might want to check with the folks at Select Plastics in Norwalk, CT. They do great work at a premium price......and they give free advice!
Regards,
Red

[Alden68]

The hatch has two panels roughly 10 x 21 so they are fairly good size. Definitely not looking for weight reduction as my boat is essentially a sailing cow and I'm sure lexan won't speed her up!

Loewe - I'll look them up....they might be just the ticket.

Thanks.

[sailingdog]

Given that Lewmar uses 3/8" plexiglass on their ports, which measure 20.5" x 15.375", as seen here. I would suggest that as a minimum thickness for your ports, which are roughly comparable in size.

I hope that helps... BTW, that is from their Ocean series of hatches, which I believe are slightly lighter construction than their other hatches. Their Medium profile hatch has a glazing thickness of 1/2".

[Alden68]

Thanks SD. That makes a lot more sense than .118" !

[sailingdog]

Glad to help... That should give you a good ballpark of how thick a piece of Lexan you'll need. Lexan, IIRC, is a bit stronger than plexiglass or acrylic, so you should be pretty good with 3/8" Lexan... gives you a bit of extra strength.

[Valiente]

I have 1/2" lexan throughbolted through steel frames on all my fixed ports and 1/4" tempered glass on the opening ports, which will take storm shutters. My forward hatch looks like it came off a tank. 0.118" or less than 1/8th of an inch is a bad joke I wouldn't expect to see on a lake daysailer, never mind a forward hatch. A dropped can of beer from mouth level could conceivably take it out.

[sailingdog]

Valiente-

Your boat is a tank.. so I'm not surprised... it is a steel boat as I recall...