I forgot one important reason for installing syntactic foam and then a polyurea coating on the inside of a metal sub. Reducing condensation by a large degree. After seeing how much trouble Karl Stanley has with condensation, I wanted to design in a way to deal with it.
If the moist air can't find a cold surface to condense on then we win.
Szybowski
From: brenthartwig@hotmail.com
To: personal_submersibles@psubs.org
Subject: [PSUBS-MAILIST] KL-250's Syntactic Foam Data
Date: Fri, 10 Jul 2009 00:28:58 -0700
Hi Brian,
I'm installing syntactic foam for a number of reasons. I'll list them in the order I find most important at the moment.
1. Extra Collision protection
2. None Compressible, None Molding Insulation from cold and heat
3. A large amount of hydrostatic load protection
4. Echo reduction
5. Smoothing out the interior for easy cleaning
6. Practice working with Syntactic Foam
========================================================
Syntactic foam is the only foam I know of that will not crush with the hydrostatic pressure I intend to expose it to during wet exit training with this sub. Also mold and mildew love fiberglass and cork insulation. Have you ever had to clean up beer, or that lovely fluid people discharge when they get car sick, out of your vehicle? All Ill need is a garden hose and a shop vac.
I have though of using several layers of the foil bubble rap insulation you see in the hardware store for raping around hot water tanks and what not. Since it will simply compress the bubbles when pressure is applied, and not break them. But you would still have water on both sides of that material that would take some time to dry.
Since I'm replacing the weakest parts of the original K-250 sub design, such as the blown dome and the forward viewport assembly. I plan to upgrade the subs operational depth to 500 fsw. So I guess that would make it a KL-500. ;}
The polyurea coatings are many times used in sealing concrete in large aquariums and ponds. They say if you let them cure long enough they will not harm the fish and other aquatic life. How longs that is, I would expect would depend on a number of factors, such as chemical formula, thickness, location, heat, airflow, etc. I do know that the fast cure coatings like Rhino and Turboliner seem to off gas very quickly. They use these coatings on the inside of Hummers, Jeeps, boats, kitchens, and what not. If you can't smell it any more when you close the hatch I would say your good to go. But it might take a few weeks with some coatings.
Perhaps this is a good place to use the canary in the coal mine method. As for me I prefer to use mosquitos. ;}'
Regards,
Szybowski
From: ojaivalleybeefarm@dslextreme.com
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] Polyurea Coatings for Submarines
Date: Thu, 9 Jul 2009 20:53:21 -0700
Brent,
Are you
insulating the inside of your sub against the cold? If so why the
syntactic foam instead of another type? That isocyanurate tends to out gas
in think, might want to be carful of that in a closed
environment.
Brian
I
have two local friends, that spray polyurea coatings commercially.
One sprays in on there steel dock weldments and other items. The brand they
use is TurboLiner. At the moment I plan to have them spray the interior
of my sub after all the syntactic foam is cured.
http://www.turboliner.com/turbo_liner_vs_others.html
"Polyurea
is a type elastomer that is
derived from the reaction product of an isocyanate
component and a synthetic resin blend component through step-growth polymerization.
Practical
uses
Truck bed linersPolyurea truck bed
liners form a durable, water and air-tight, permanent liner for the exterior
of pick up trucks, dump trucks and steel containers. These durable, easy to
clean and abrasion resistant liners protect utility trucks from their harsh
duty environments. They also protect against rust and corrosion from damaging
trucks and containers. Polyurea liners can also be applied in varied thickness
to meet any specific application demand. Sprayed on truck bed liners are
available in many colors and can be wrapped over the top edge of the truck bed
to provide added protection from impact and abrasion.
Pipe and pipeline coatings and
liningsPolyurea coatings and linings are increasingly being used
to protect steel pipes from corrosion. Polyurea has demonstrated its ability
to last longer than paint and maintenance services and costs are reduced.
Polyurea is a great protective coating system for pipes that are insulated
with polyurethane foam. Polyureas are also being used to line the inside of
water and sewer pipes for infrastructure rehabilitation work.
Bridge coatingPolyurea's ability to
outlast paint and fight off corrosion is a major reason these systems are
being specified for bridge deck and structure coating by State DOT's around
the nation. The most common applications of polyurea coatings on bridges are
over steel and concrete.
Joint fill / caulkPolyurea is being
successfully used as a multi-purpose joint fill, caulking and sealant
material. It can provide a flexible, durable, weather-tight and traffic
resistant seal for all types of building joints, such as expansion joints and
control joints in masonry floors, perimeter joints, panels and doors, water
reservoirs, etc. It has excellent crack-bridging properties with high
elongation and tensile strength. The fast cure time and insensitivity to
moisture allows for a quicker installation with a wider application window.
Proper surface preparation and substrate condition is always
necessary.
Holding tanks
Tank coatingsPolyurea coatings protect
steel tanks from corrosion, chemicals, and other natural weather and jobsite
elements. With proper surface preparation, substrate condition, formulation
choice, primers, and installation procedures, polyurea goes on fast and stays
on long. Polyureas are great for extending the life of older tanks and can
offer limited structural characteristics as well. These systems can be applied
during primary construction or in a retrofit environment. With their fast cure
times they are ideal for retrofit since down time is significantly minimized
compared to some competing materials.
Tank liningsPolyurea linings are
resistant to many chemicals and industrial liquids. With their fast
application advantages and ability to adhere to properly prepared substrates,
polyureas are ideal for new storage tank primary lining and rehabilitation
projects.
Waste water treatment liningsFast
cure, chemical and abrasion resistant, concrete primary and secondary
containment linings.
Aquarium liningAquariums have also
found benefits with polyurea. The ability to form to properly prepared custom
shaped walls and themed ornaments make this system desirable. A spray applied,
water resistant liner, available in a variety of colors with rapid return to
service installation is why facility owners are turning to
polyurea.
Landscape & water
containmentLandscape designers and contractors have found similar
benefits with polyurea. Polyurea is often used to contain water for ponds and
pool decorations to form a primary containment liner. Use of geotextile
material is common when applying polyurea over dirt. Proper surface condition
is vital when applying over concrete and most other
substrates.
MarineAbove the water line and below,
polyurea can be very effective in protecting steel, aluminum, and fiberglass
in a variety of water sport and commercial marine applications. From sound
attenuation for fishing canoes, to fish hold liners, to hull protection and
bilge liners, polyureas are used in many abrasion, chemical and corrosion
resistant marine applications. "
http://en.wikipedia.org/wiki/Polyurea
Sounds
like a good product for coating concrete submarines as
well.
Another brand of polyurea
coatings is http://www.xtremeliners.com/
There
is also some interesting polyurea data here in this PDF.
http://www.kta.com/knowledge/PACE2005/Polyurea%20Coatings%20CLO.pdf
Regards,
Szybowski
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