Empathy List Archives

L

LRZeitlin@aol.com

Wed, Jun 13, 2001 3:13 PM

In a message dated 6/13/01 4:04:18 AM, Bill writes:

<< On another note, I just finished replacing the windshield on my fly bridge.
I used 3/16 inch, tinted Lexan. I used the old pieces for a pattern; cut
the stuff with a 10 tooth/inch saber saw, and sanded the edges down to 600
grit. The Lexan seems to be more flexible than the original Plexiglas as I
was able to fit the sharpest curves without heating it. It turned out to be
a much easier job than I had anticipated. >>

Lexan (polycarbonate) is great stuff (although expensive). It has MUCH higher
impact resistance than ordinary Plexiglass (acrylic) and is virtually
unbreakable in a marine environment. I would use it to reglaze all window
areas directly exposed to possible green water impact. However it is less
abrasion resistant than Plexiglass and scratches readily. It may well be
overkill for an exposed flying bridge windscreen where it does not have to
resist solid water impact. Most plastics suppliers sell abrasion resistant
carbonate and acrylic sheeting for exterior glazing that will resist
scratching better than ordinary plastics. These are coated with silicon
layers on both sides and would be best for windscreens with wipers.

Replace your own windows. It ain't brain surgery.

Larry Zeitlin

In a message dated 6/13/01 4:04:18 AM, Bill writes: << On another note, I just finished replacing the windshield on my fly bridge. I used 3/16 inch, tinted Lexan. I used the old pieces for a pattern; cut the stuff with a 10 tooth/inch saber saw, and sanded the edges down to 600 grit. The Lexan seems to be more flexible than the original Plexiglas as I was able to fit the sharpest curves without heating it. It turned out to be a much easier job than I had anticipated. >> Lexan (polycarbonate) is great stuff (although expensive). It has MUCH higher impact resistance than ordinary Plexiglass (acrylic) and is virtually unbreakable in a marine environment. I would use it to reglaze all window areas directly exposed to possible green water impact. However it is less abrasion resistant than Plexiglass and scratches readily. It may well be overkill for an exposed flying bridge windscreen where it does not have to resist solid water impact. Most plastics suppliers sell abrasion resistant carbonate and acrylic sheeting for exterior glazing that will resist scratching better than ordinary plastics. These are coated with silicon layers on both sides and would be best for windscreens with wipers. Replace your own windows. It ain't brain surgery. Larry Zeitlin

A

adagio@our.net.au

Wed, Jun 13, 2001 11:55 PM

on 6/14/01 1:13, LRZeitlin@aol.com at LRZeitlin@aol.com wrote:

Lexan (polycarbonate) is great stuff (although expensive). It has MUCH higher
impact resistance than ordinary Plexiglass (acrylic) and is virtually
unbreakable in a marine environment

Sorry, but I don't agree with that statement. In the archives are some
earlier posts that go into the strength of glazing materials in some detail.
Below are the parameters for tempered glass, acrylic and lexan. When you run
the Lloyds engineering method for Adagio's front windows, they need to be
34mm in acrylic, 40mm in lexan.

The impact resistance of Lexan relates to high-velocity projectiles, not to

Cheers,

Steve

   Please view in a fixed-width font such as Monaco or Courier.

+---+----------------------------------+----------+-----------+-----------+
| | | Temp | Acrylic | Lexan |
+---+----------------------------------+----------+-----------+-----------+
| | | Glass | | |
| | | (kPa) | (kPa) | (kPa) |
| | Allowable working stress - Sigma | 58000 | 24725 | 19654 |
| | Young's Modulus - E | 68.9E+06 | 30.0E+05 | 19.0E+05 |
| | Ultimate tensile bending stress | 17.5E+04 | 74.6E+03 | 59.3E+03 |
| | Density (also 1mm/sq.meter) | 2.60 | 1.20 | 1.20 |
| | Weight/cu.meter | 2600 | 1200 | 1200 |
| | Thermal expansion %/degree C | 0.0075% | 0.0070% | 0.0070% |
+---+----------------------------------+----------+-----------+-----------+

on 6/14/01 1:13, LRZeitlin@aol.com at LRZeitlin@aol.com wrote: > Lexan (polycarbonate) is great stuff (although expensive). It has MUCH higher > impact resistance than ordinary Plexiglass (acrylic) and is virtually > unbreakable in a marine environment Sorry, but I don't agree with that statement. In the archives are some earlier posts that go into the strength of glazing materials in some detail. Below are the parameters for tempered glass, acrylic and lexan. When you run the Lloyds engineering method for Adagio's front windows, they need to be 34mm in acrylic, 40mm in lexan. The impact resistance of Lexan relates to high-velocity projectiles, not to Cheers, Steve Please view in a fixed-width font such as Monaco or Courier. +---+----------------------------------+----------+-----------+-----------+ | | | Temp | Acrylic | Lexan | +---+----------------------------------+----------+-----------+-----------+ | | | Glass | | | | | | (kPa) | (kPa) | (kPa) | | | Allowable working stress - Sigma | 58000 | 24725 | 19654 | | | Young's Modulus - E | 68.9E+06 | 30.0E+05 | 19.0E+05 | | | Ultimate tensile bending stress | 17.5E+04 | 74.6E+03 | 59.3E+03 | | | Density (also 1mm/sq.meter) | 2.60 | 1.20 | 1.20 | | | Weight/cu.meter | 2600 | 1200 | 1200 | | | Thermal expansion %/degree C | 0.0075% | 0.0070% | 0.0070% | +---+----------------------------------+----------+-----------+-----------+

WS

water_sparky@yahoo.com

Thu, Jun 14, 2001 5:40 PM

My old engine had water in the oil. I have installed a new engine and don't
want the same thing to happen. I have talked to the people who make the
Vernalift waterlift mufflers and they have stated that the muffler inlet
should be at least 12" below the water injection point on the engine's
exhaust outlet.

My problem is that none of the Vernalift or Vetus Waterlock mufflers will
fit into my boat and place the muffler inlet that far below the engine's
exhaust outlet (unless I strap it under the keel :-). My old engine had an
Onan type waterlift muffler with it's inlet only about 3" below the
injection point (so I assume that is how I was getting water in the oil).

My engine is at or just below the waterline and the exhaust hose runs at
least 20' aft to the overboard discharge point. Does anyone have any
suggestions/remedies?
Thanks.
Joseph

Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com

My old engine had water in the oil. I have installed a new engine and don't want the same thing to happen. I have talked to the people who make the Vernalift waterlift mufflers and they have stated that the muffler inlet should be at least 12" below the water injection point on the engine's exhaust outlet. My problem is that none of the Vernalift or Vetus Waterlock mufflers will fit into my boat and place the muffler inlet that far below the engine's exhaust outlet (unless I strap it under the keel :-). My old engine had an Onan type waterlift muffler with it's inlet only about 3" below the injection point (so I assume that is how I was getting water in the oil). My engine is at or just below the waterline and the exhaust hose runs at least 20' aft to the overboard discharge point. Does anyone have any suggestions/remedies? Thanks. Joseph _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

T

tclem@acadia.net

Thu, Jun 14, 2001 5:45 PM

FWIW, my Yanmar 6LP's have no mufflers, are not loud, and the admiral loves
their sound!

Tom

At 01:40 PM 6/14/2001 -0400, Joseph Pfab wrote:

My engine is at or just below the waterline and the exhaust hose runs at
least 20' aft to the overboard discharge point. Does anyone have any
suggestions/remedies?

FWIW, my Yanmar 6LP's have no mufflers, are not loud, and the admiral loves their sound! Tom At 01:40 PM 6/14/2001 -0400, Joseph Pfab wrote: >My engine is at or just below the waterline and the exhaust hose runs at >least 20' aft to the overboard discharge point. Does anyone have any >suggestions/remedies?

S

scaramouche@tvo.org

Thu, Jun 14, 2001 9:12 PM

adagio@our.net.au writes:

Lexan (polycarbonate) is great stuff (although expensive). It has

MUCH higher

impact resistance

I have to replace side windows (tintesd) on my sailboat. Important is
that holes (countersunk) have to be drilled without cracking. What is
the best material anyone has ever tried for this? Windowas are oval
about 4 ft by 1.2.

Any suggestions?

adagio@our.net.au writes: > >> Lexan (polycarbonate) is great stuff (although expensive). It has >MUCH higher >> impact resistance I have to replace side windows (tintesd) on my sailboat. Important is that holes (countersunk) have to be drilled without cracking. What is the best material anyone has ever tried for this? Windowas are oval about 4 ft by 1.2. Any suggestions?

trawlers@lists.trawlering.com

TWL: Re: Lexan vs. Plexiglas