That's all right Alan, I knew long in advance that if I monkeyed with the K-250 design much I would be asked some questions. I've worked up two different types of thru hulls for double composite 1 ATM sub hulls with syntactic foam sandwiched between them, that I've been hoping to get a chance to finish on CAD to show you. I'm working with four composite professionals to proof the designs. One is a composite sub guy, one is a composite boat guy, one is a composite aircraft guy, and one is a composite boat and aircraft guys. So I think I've covered all my bases. Now all I need is a composite car guy. ;}
In regards to impact protection, the Bionic Dolphin and BioniOrca are designed as crash capsules with a sandwiched syntactic foam core. It's tough stuff and it's interlocked with my new and old support ribs.
When my sub is done, it might be able to operate as a 1 ATM, ambient, and wet sub if I want. The wet sub part requires removing some of lead weights, and inflating the amas. Getting the sub to surface after flooding can be done a number of ways. The preferred way is to close the hatch with SCUBA gear on and crack open some high pressure air from the SCUBA tanks, and let the water drain out the two large over pressure valve in the floor. Then add some air to the MBT's and up see goes.
I could also just leave the hatch open and inflate the amas and put air in the MBTs and go up. Then once at the surface use the internal sump pump to drain the sub.
Sealing all the electronics is a big subject. One that I don't have all figured out. But the basic plan is to use as much SCUBA type equipment that is designed to get wet at depth as possible, and the rest either sealing them in pods, pot them, or make them easily removable for wet exit training. Wires will either be solid or run in tubing that is oil filling with a oil bladder to keep the pressure the same inside as is outside, like was done on the Sea Cliff and Turtle DSV's. Same with the FRP battery box. The man designing and making my FRP battery box is the same one the made them for the last Turtle DSV refit. I think I'm in good hands.
I expect wet exit training with my sub to be with in the recreational SCUBA limits. Beyond that only time and tech training will tell. At conventions it might just be at 30 to 50 fsw in clear water with several safety divers there. Wet exit training it some thing Navies all over the world practice, and a number in this group are interested in it as well. I believe having a real working sub that we can do this with, is a worth while project.
Regards,
Szybowski
From: alanjames@xtra.co.nz
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] KL-250's Syntactic Foam Data
Date: Sat, 11 Jul 2009 08:49:56 +1200
Hi Brent,
It's pick on Szybowski day today.
I looked at the syntactic foam as a sandwich material between fiberglass, & its great
for that, however its weak point is the through hulls.
I can't see how it would strengthen against impact very well on the inside without being the core in a sandwich.
Also there would be weak points round through hulls etc as you'd have to cut and glue to fit round & under pipes etc.
Wouldn't any foam do that would return to its original form after compression, If its for escape practice purposes.
I'm a bit ignorant of the process of practicing an escape from your sub.
What depth are you intending to escape from ?
What about the electronics being flooded ?
How do you get the sub up, it must weigh tonnes once the airs out of it.?
Also it sounds a bit like practicing rolling your car in case it rolls.
regards Alan.
----- Original Message -----
Sent: Friday, July 10, 2009 7:28 PM
Subject: [PSUBS-MAILIST] KL-250's Syntactic Foam Data
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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