Pete Verdon wrote:
Duncan Heenan wrote:

"Pete Verdon" d wrote


How would you fix the forehatch board in place if the glass/perspex
were to break?


Mine are fashioned on the assumption that the whole of the hinged
opening part, frame and all, has gone (or is folded flat), and simply
blanks off the opening.


Right, but how do you plan to secure it in place?

I'm not trying to nitpick, by the way, I'm just curious.

Pete
The way we do it with portlight emergency covers is with a long bolt (or
two) and a wing nut reaching inside to a wooden bar that goes across the
hole like a damage control plate.

Terms here in the colonies are somewhat different.

Plate glass is made by flowing the molten glass onto a (preheated) iron
slab. It is the truest, flattest, available; but hasn't been made for
decades. What one gets now is "float glass" made by flowing the glass onto
a (shallow) puddle of mercury. It's almost as flat, but not optical grade.

The heat treated and pre-stressed stuff for automobiles is "tempered" glass.
The idea is to avoid the great shards that are generated when plate glass is
broken. (My 1933 Ford had plate glass. I'm glad no one was seated in the
back seat when I rolled it.)

Anyone interested in glass should visit the Corning museum in Corning, NY.
Besides duplicates of the various presidential gifts made over the years,
they have ALL species of glass on display.

Roger

http://home.earthlink.net/~derbyrm

"Steve Lusardi" wrote in message
...
Nigel,
Houdini sells these with polycarbonate as well, but they are junk. If all
you want to do is stay tied up, they are probably OK. I dropped 1500
pounds Sterling on 2 companionway hatches a while back. These were
sliders. No matter how I installed them, they stuck and would never slide
well. They scratched and they leaked. I threw them away in the end and
designed and built my own out of stainless and armor glass.

Please do not confuse the different categories of glass. There are many
and they go by different names in different countries. Automotive glass in
the UK is called toughened glass. This glass is heat treated and cooled
quickly. This leaves the glass very hard and highly stressed. This is the
wrong stuff to use as hatches. It is also called plate glass. In the UK
the glass you need is armor glass. This glass is also heat treated but the
process used causes the glass to be stress relieved and it is delivered in
an annealed state. It is most commonly laminated with plastic in between
panes of glass for bullet proofing. It can be found up to 12mm thick. I
use it 10mm thick unlaminated. It is very scratch resistant. It doesn't
fade and you can literally beat on it with a hammer and bow it under
severe load and it doesn't break. It is the best, but it isn't cheap.

One responder mentioned Gebo Hatches. Even though they are made in France,
they are very good. I have 13 in use. They do not leak and parts are
readily available.
Steve


"Nigel" wrote in message
...
I need to buy a new deck hatch. The choice seems to be either a Lewmar 60
or a Houdini super 50 foredeck hatch. They are both the same size
(they're both the same size) The Lewmar has Perspex (12mm I think) and the
Houdini 6mm toughen glass. Houdini are a lot cheaper and I quite like the
idea of toughened glass, but is toughened glass likely to shatter into
little squares if it's walloped by a clew or similar object

Or just drill two holes in the panel, pass a line thru, caulk at the holes,
and then tie it to the stick underneath. Easier to stow. (Twist stick to
tighten.)

Roger

http://home.earthlink.net/~derbyrm

"Gary" wrote in message
news:AZPef.521939$tl2.488306@pd7tw3no...
Pete Verdon wrote:
Duncan Heenan wrote:
"Pete Verdon" d wrote
How would you fix the forehatch board in place if the glass/perspex
were to break?

Mine are fashioned on the assumption that the whole of the hinged
opening part, frame and all, has gone (or is folded flat), and simply
blanks off the opening.

Right, but how do you plan to secure it in place?
The way we do it with portlight emergency covers is with a long bolt (or
two) and a wing nut reaching inside to a wooden bar that goes across the
hole like a damage control plate.

On Thu, 17 Nov 2005 02:13:09 UTC, "Roger Derby"
wrote:

The heat treated and pre-stressed stuff for automobiles is "tempered" glass.

That's what we call "toughened" over here - it can be either heat
toughened or chemically toughened.

ian

"Pete Verdon" d wrote in
message ...
Duncan Heenan wrote:
"Pete Verdon" d wrote

How would you fix the forehatch board in place if the glass/perspex were
to break?

Mine are fashioned on the assumption that the whole of the hinged opening
part, frame and all, has gone (or is folded flat), and simply blanks off
the opening.

Right, but how do you plan to secure it in place?

I'm not trying to nitpick, by the way, I'm just curious.

I have a small fitment on the inside to which a cord can be attached to lash
it down on to something inside the cabin. It is only ever intended as a
short term emergency thing and so aesthetics don't really matter.

On Thu, 17 Nov 2005 02:13:09 GMT, "Roger Derby"
wrote:

Terms here in the colonies are somewhat different.

Plate glass is made by flowing the molten glass onto a (preheated) iron
slab. It is the truest, flattest, available; but hasn't been made for
decades. What one gets now is "float glass" made by flowing the glass onto
a (shallow) puddle of mercury. It's almost as flat, but not optical grade.

Float glass is floated on molten tin.
Much flatter than the most part of pre-float stuff.

Brian Whatcott Altus OK