Perspex window thickness?

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IanVonLux

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Hi,

Looking at buying new perspex windows and struggling to find any recommendations about desired thickness.

I'm assuming that some clever person has worked out the minimum thickness of perspex required per maximum height or width of the window span???

Cheers,
Ian
 
IanVonLux said:
Hi,

Looking at buying new perspex windows and struggling to find any recommendations about desired thickness.

I'm assuming that some clever person has worked out the minimum thickness of perspex required per maximum height or width of the window span???

Cheers,
Ian
Click to expand...
Mr Van de Stadt worked out that my portlights should be 13mm thick and the saloon windows 10mm. The boat is designed for heavy weather so may be OTT if your boat isnt
 
geem said:
Mr Van de Stadt worked out that my portlights should be 13mm thick and the saloon windows 10mm. The boat is designed for heavy weather so may be OTT if your boat isnt
Click to expand...

I expect that I'm going to get a lot of similar responses, I'm hoping for something more scientific...

What are the dimensions of your saloon windows?
 
IanVonLux said:
I expect that I'm going to get a lot of similar responses, I'm hoping for something more scientific...

What are the dimensions of your saloon windows?
Click to expand...

You could employ beam theory for a simply supported beam. Work out the second moment of inertia and the load for forces derived from a body of water under X meters head.

Or you could just state that 8mm polycarbonate will be perfectly sufficient for anything short of a mortar round
 
I've replaced Perspex windows on a Jaguar 27 and a Moody33 - both were 6mm thick, long but only about 7" tall. I did in fact try and break the J27 windows which were badly crazed but it was very difficult and had to resort to a club hammer with the Perspex clamped in a heavy vice and it took about 3 blows before it broke. Very strong especially as it was not in it's frame. I was impressed with the strength.
 
IanVonLux said:
I expect that I'm going to get a lot of similar responses, I'm hoping for something more scientific...

What are the dimensions of your saloon windows?
Click to expand...

Hope this is a bit more what you're looking for...

My boat is Lloyds 100A5 rated and has a portlight thickness of 10mm. Height of portlights is 140mm, maximum portlight length is 670mm. Portlights are situated in CE Area A2.
 
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Would it not be a lot simpler of the OP took the trouble to give at least some idea of the size of his windows? Without that information, how does he expect to get an informed answer?
 
I might have thought, possibly erroneously, Classification Societies would have this at their fingertips, or on their websites. Though finding the data might be difficult.

Jonathan
 
I had my front windows re done at 10 mm thickness nice shade of Blue Perspex and 16 mm for a very large hatch in the coach roof , which my daughter and her friend can easily stand on and jump around , no movement or give , Front windows seem solid at 10mm
 
I have just reglazed the wheelhouse side windows on my LM27 using 10mm perspex. The windows are about 1.2m long by 0.6m tall. The 10mm seemed over the top when I was cutting to shape, but actually fine once fitted, and I feel happier with a good thickness of material where the fixings are.
 
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