[C320-list] Companion way hatch-is NOT acrylic

[Jack Brennan]

Wow. That puts a whole different spin on things. A 36- x 36-inch sheet of smoked polycarbonate (Lexan?) at McMaster-Carr is $559. A 48- by 48-inch sheet, which is what you would need to match the original exactly, is $970.

That would be really painful if you made a mistake cutting.

I've been having trouble getting quotes on acrylic for this project in part, I suspect, because of the dimensions. To get the correct-sized hatch, you need to buy a 48- by 96-inch sheet at $250 to $300 plus delivery and cutting charge. No one wants to give me a custom cut and get stuck with the partial piece.

For now, I've decided to experiment with the King Starboard route, partly because I was able to get a 24- by 48-inch sheet of half inch for $70 at Home Depot. That gives me the correct width of 36 and 3/8 inches.

With the leftover cut, I can attach a 3 and 5/8 inch attachment to the rear side of the hatch, where it slides under the hood and won't be seen. I think the extra length is there to keep water out of the cabin.

As I said before, I like the Starboard option because reduces the sunlight coming into the cabin. During hot Florida summers, the spot under the sliding hatch never cools, no matter how long the AC is running.

Who knows, I may eat my words and be buying that $970 piece from McMaster-Carr.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.





________________________________
From: C320-list <c320-list-bounces at lists.catalina320.com> on behalf of Jeffrey Kapec via C320-list <c320-list at lists.catalina320.com>
Sent: Friday, October 25, 2024 8:47 PM
To: c320-list at lists.catalina320.com <c320-list at lists.catalina320.com>
Cc: Jeffrey Kapec <jkapec at tkdg.com>
Subject: [C320-list] Companion way hatch-is NOT acrylic

Hello to All:

I read this string and thought I would perform a reality check on
the assumption that the sliding hatch is acrylic.  I believed otherwise by
the nature of the material and the grey cast tint.  I too own a 320 Hull
718.  I knew that the companionway was Polycarbonate and not acrylic.
Being a professional Industrial Designer for 40 years I know my polymers.
Nevertheless I did some research with AI.  Here is what I found, and I
agree completely with the overview.  I have designed products with acrylic
and with polycarbonate.  The most important factor is the ductility of
polycarbonate which will accommodate flexural bending and very high impact
loading supporting a great deal under stress.  So, for example, if you have
ever closed the hatch and had to stand on it ....the polycarbonate would be
just the material for that.  Acrylic on the other hand does not have nearly
as much ability to sustain load before it cracks.  Just look up the
mechanical properties ini Modern Plastics engineering.  The polycarbonate
in that thickness and color may be purchased online by a number of plastics
suppliers.

For reference....

AI Overview
Learn more <https://support.google.com/websearch?p=ai_overviews&hl=en>
…Opens in new tab
<https://support.google.com/websearch?p=ai_overviews&hl=en>
The Catalina 320 companionway hatch is made of polycarbonate:

   - *Polycarbonate*: A strong, impact-resistant material that's ideal for
   boat windows and hatches. Polycarbonate is more durable than acrylic and
   can withstand impacts 250 times better than glass.
   - *Acrylic*: A transparent material that tends to be glossy and stays
   clear over time.

Marine plastics and acrylic are the preferred materials for boat hatches
because they are reliable, customizable, and easy to fabricate.

Jeff Kapec
Petite Suite Hull 718

--

Jeffrey Kapec

*Tanaka Kapec Design Group*

11 Brookfield St.   Norwalk, CT 06851

203.846.3666


www.tkdg.com<http://www.tkdg.com>