| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1081.1 | disadvantages of clear | CADSYS::SCHUMANN | Say NO to bugs | Wed Dec 28 1988 10:47 | 13 |
| > I was thinking of clear as opposed to "smoked" as I have seen.
Clear plastic (regardless of type) shows all scratches very readily, and
scratches easily. If you get a light smoke, the scratches will not be as
obvious. Also, light smoke will give you more privacy alongside the dock.
Look under plastics in the yellow pages. Many sheet plastics dealers will
sell individual sheets or even partial sheets at retail. There are many
different kinds of plastics, and the plastics dealers can give you
information on strength, UV-resistance, yellowing, scratch-resistance, etc.
--RS
|
| 1081.2 | A vote for Cadillac | NETMAN::CARTER | | Wed Dec 28 1988 11:17 | 8 |
| If you are local, I can recommend Cadillac Plastics in Somerville
Ma. I will be getting Lexan from them during the off season. Have
done business with them in the past. They know what they sell and
are good for advice.
dave
|
| 1081.3 | Ask for Lexan | KOBAL::FANEUF | | Wed Dec 28 1988 11:22 | 8 |
| The standard heavy-duty plastic for this application is Lexan (brand
name), as found in many existing hatches such as Bomar. A standard
hatch thickness is 3/8", occasionally 1/2". I wouldn't consider any
other plastic for this use.
Ross Faneuf
|
| 1081.4 | Lexan | MSCSSE::BERENS | Alan Berens | Wed Dec 28 1988 11:26 | 22 |
| I would recommend using Lexan, either 1/4" or 3/8" thick. Lexan is
incredibly strong (fighter aircraft canopies and bullet proof windows
are among the applications). Roughly, 3/8" Lexan is over three times as
strong as 1/4" (I used 3/8" for our hatches). Lexan is substantially
stronger than acrylic (Plexiglas). It does scratch fairly easily,
though. If your hatches are flat, and you can afford the extra cost, use
Margard Lexan. This has a scratch-resistant coating. I wish I'd used it
instead of regular Lexan. Lexan can be sawn (a triple chip carbide blade
is recommended for table saws) and drilled readily. GE (the main
manufacturer) publishes a design brochure that I got at Commerical
Plastics in Somerville (they have the lowest prices I've found and a
vast variety of plastics). Lexan has a high thermal coefficient of
expansion -- this means it expands and contracts a lot with temperature
change -- and this must be taken into account in the hatch design. I
used black butyl tape (the stuff used on car windows) and one of the
recommended GE industrial silicones to seal the Lexan into my teak
hatches. No problems or leaks after three years.
I would also recommend using the gray tinted Lexan. It will reduce that
amount of sunlight (heat) entering the cabin considerably. The tint is
not very dark.
|
| 1081.5 | | MSCSSE::BERENS | Alan Berens | Wed Dec 28 1988 14:51 | 7 |
| re .3:
As I recall from reading hatch manufacturers' blurbs, Lexan is the
exception rather than the rule. Most use acrylic (Plexiglas). If I
recall the Lexan literature correctly, 1/4" Lexan is stronger than 1"
acrylic.
|
| 1081.6 | | ASABET::HO | | Wed Dec 28 1988 16:03 | 14 |
|
One thing to consider for the main entry drop-in doors is whether
Lexan floats. These have been known to fall overboard (don't ask
how I know this).
One plastic that definitely doesn't float is delrin. A few seasons
back on a day with little air and lots of rollers and a mast that
was whipping back and forth, my delrin mast blocks wiggled out of
their mast partners. Until I heard the splash I didn't even know
they had escaped. All I got was a fleeting glance as they sank
out of sight. The next set got made out of teak.
- gene
|