While fishing in Sitka, AK last year I became aware
that some of the Charter Captains are switching to
Allen Marine Aluminum Boats. While on their web site I
came across their 33’ Catamaran:

HYPERLINK
"http://www.allenmarineinc.com/33catcharter.html"http:
//www.allenmarineinc.com/33catcharter.html I have no
idea what they cost, but there is contact information
on their site.

One of the Captains indicated that Allen Marine is
spraying on some kind of insulation to keep
condensation down, and improve warmth along with some
sort of diesel heating unit. I recall hearing
somewhere that over time the older spray on insulation
absorbs water, and begins to fall off.

With the long term rising cost of fuel I can see
advantages with Aluminum – lighter weight, less fuel
burn. However, some of my coldest days ever on the
water have been in open Aluminum boats.

Has anyone had any recent experience with insulated
Aluminum boats?

Sincerely,

Jim Garner

HYPERLINK
"mailto:jimgarner1@earthlink.net"jimgarner1@earthlink.
net

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Jim,

I have an aluminum catamaran with a urethane foam insulation sprayed
inside the hulls.  Zero problems that I can tell, though the sprayed
areas are difficult to access and inspect.  Those areas are not exposed
to bilge water.  I've owned the boat for 8 years.  I haven't run my boat
pre-foam since it was applied during construction, but the boat is quiet
and warm, and I suspect it would be just the opposite w/o the foam.

Concerns have been raised regarding sprayed foam on aluminum fuel tanks

• the foam prevents oxygen fro reaching the metal.  Aluminum's
  anticorrosive properties are in part due to the aluminum oxide layer
  that forms on the surface.  If the oxygen can't get to the surface, that
  oxide doesn't form and fuel tanks have been known to corrode.  Probably
  not as big of an issue with the 5000 series of marine grade aluminum.

I haven't seen an Allen Marine cat up close yet, but have heard good
things about them.  Allen Marine's primary business is building large
commercial aluminum catamaran ferries and tour boats.  They know cats
and they know aluminum - a high quality firm.  I'd guess that their
sport charter boat would cost a minimum of $200K, probably more.

Aluminum's a wonderful boat building material, but it does have its own
set of drawbacks to take into consideration.

Bob Deering
Juneau Alaska

-----Original Message-----
From: power-catamaran-bounces@lists.samurai.com
[mailto:power-catamaran-bounces@lists.samurai.com] On Behalf Of Jim
Garner
Sent: Monday, January 02, 2006 7:17 AM
To: 'Power Catamaran'
Subject: [PCW] Allen Marine 33' Aluminum Catamaran

While fishing in Sitka, AK last year I became aware that some of the
Charter Captains are switching to Allen Marine Aluminum Boats. While on
their web site I came across their 33' Catamaran:

http://www.allenmarineinc.com/33catcharter.html I have no idea what they
cost, but there is contact information on their site.

One of the Captains indicated that Allen Marine is spraying on some kind
of insulation to keep condensation down, and improve warmth along with
some sort of diesel heating unit. I recall hearing somewhere that over
time the older spray on insulation absorbs water, and begins to fall
off.

With the long term rising cost of fuel I can see advantages with
Aluminum - lighter weight, less fuel burn. However, some of my coldest
days ever on the water have been in open Aluminum boats.

Has anyone had any recent experience with insulated Aluminum boats?

Sincerely,
Jim Garner
mailto:jimgarner1@earthlink.net jimgarner1@earthlink.net

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1/2/2006

-----Original Message-----
From:  Robert Deering

Concerns have been raised regarding sprayed foam on aluminum fuel tanks

• the foam prevents oxygen fro reaching the metal.  Aluminum's
  anticorrosive properties are in part due to the aluminum oxide layer
  that forms on the surface.  If the oxygen can't get to the surface, that
  oxide doesn't form and fuel tanks have been known to corrode.  Probably
  not as big of an issue with the 5000 series of marine grade aluminum.

REPLY
Robert, once the aluminum has oxidized, doesn't the  surface film remain
intact?  How about anodizing the tank?

Arild

Does anyone have specs for the new 27' Motor Cat?  The website provides
specs for the 30; LOA 29'11", beam 9'5", towing wt. 6000#  A bit much
for easy towing. Might they be one and the same? Thanks!  Jon Karna