Making the switch(?) OR acting as the Dive Tribes "Crash Test Dummy"

[QuarterMaster]

The true(?) cost of CO2.

Well, all may not be rosy, or cheaper, in CO2 land....

I wanted to do a cost analysis just to see if it was actually more cost effective than Propel or Freon.

Kinda difficult since CO2, Propel and Freon not only have different properties, but aren't really "standard" with regards to units of purchase.

So I tried too nail to down to "Cost per Gram", then that converted to g/CC and expansion ratio vs how many grams actually used to fill up a 1 Liter volume, then calculate that cost.

I was surprised to find CO2 was the most expensive overall.

Feel free to check the methodology and math. The purchases were through Amazon (your source may be less expensive), cost is in USD.

Source CO2 (10 Cartridges)
Cost/Unit (Amazon) $16.99
Total Grams 160
Cost per Gram $0.11
Density g/CC 1.25
Cost/CC $0.13
Expansion Ratio 535
g/1l Ballast Tank 1.869
Cost per Blow $0.25
# of blows per unit sold 85.6

Source Propel (1 Can)
Cost/Unit (Amazon) $29.70
Total Grams 368
Cost per Gram $0.08
Density g/CC 0.91
Cost/CC $0.07
Expansion Ratio 306
g/1l Ballast Tank 3.2680
Cost per Blow $0.24
# of blows per unit sold 112.608

Source Freon (3 Cans)
Cost/Unit (Amazon) $43.58
Total Grams 1020
Cost per Gram $0.04
Density g/CC 1.24
Cost/CC $0.05
Expansion Ratio 274
g/1l Ballast Tank 3.649
Cost per Blow $0.19
# of blows per unit sold 279.48

Of course this is just a comparative cost analysis of the gas. Actual usage may differ. Your needs may differ. Prices may shift around in the future.

For example, my choice has been Freon for the past 4 years. I buy it by the case. 3-4 years ago a 12 pack of 12oz cans went for ~$65, when I last checked it had doubled. I thinks that's 'cuz I told all you swabs to switch due to the cost of Propel and y'all made a run on it. Or it could just be inflation lol.

I run at least every other weekend. I primarily use my Snorkel Induction to surface the boat, with gas a a backup or used to impress folks. 3-4 cans a year? Gas is often lost through charging. Either through seal leakage as its done, or definitely to get the tanked chilled to accept the gas. Fill, vent, fill again.

Co2 cartridges, being already filled WILL alleviate that. Plus I can set the discharge pressure to limit loss by not forcing everything out at once. IOW metering the output as opposed to dumping it at full tank pressure out the Schrader valve.

The only way to truly know is to test it.

Over the next week I plan to install this (photo) in the usual test platform of mine, my 1:48 Scale RC Submarine USS SHARK SSN-591. I see I need to make some mod's as the goal is to have it in the "wet".



Again, in the long run it may be as expensive as Propel, but loss from charging a reservoir will be non-existent, and convenience will be optimal, especially if you don't run that often. That and it's suitability for the larger boats may be the upside of using it. Especially when it's only for the backup and you use air induction through your snorkel mast at PD to surface, like a real combat sub.

[RCSubGuy]

Loving this, Ed. Anxiously awaiting the results of your testing.

[QuarterMaster]

I'll have it installed shortly, before next weekend. Seems REAL easy.

Feeling "Gas" happy again!

..or maybe I'm happy feeling gas??

[Albacore 569]

Excellent data Captain QM. Freon? I didn't know one could still get Freon. The damage from Freon on the ozone layer was stopped and has almost been repaired.
(that hole over the Antarctic). Interesting. Propel is still available and I am familar with that.

Thanks for the reserach. Useful.

Steve

[Schmitty1944]

Thank you Ed for that excellent cost analysis. I'm a little surprised at the results too. I think Co2 gets tremendously cheaper when you are having tanks filled vs buying the small cartridges. The cost of those is mostly the cartridge itself.

Albacore 569. "Freon" is a brand name and covers a variety of refrigerants but is mostly associated with "R-12" which was very environmentally un-friendly. Even modern forms of refrigerant (R-134a) are still bad for the environment (what isn't?) but much better than the earlier ones. The name "Freon" has become synonymous with any type of refrigerant in the same way that people use "ping pong" to describe all brands of table tennis or "Frisbee" for all flying discs.

Jason

[Das Boot]

You can get 40 12 gram cartridges for 25 bucks on Amazon.

[QuarterMaster]

Okay, the initial testing is complete and I'm going forward with installing it into the 1:48 DeBoer SSN-591.

Before I go on, the fine print for the universal leeches looking to litigate because they won't take responsibility for their own inept actions.

Disclaimer Statement

By reading my posts on this thread you have agreed....

1-With respect to the following methods that are used in this informational thread: Should you decide to implement them, you are using them AT YOUR OWN CHOICE, AT YOUR OWN RISK, without warranty AND/OR guarantee of any kind (either expressed or implied).

2-That the author (me) of his posts (mine) will not be held responsible or liable for any injury or harm you and/or others sustain, and/or damage/loss to your property and/or other owners property as a result of information obtained from this thread, or information shared by me. This includes emails, videos and text.

3-The desired intent of these posts is in the free sharing of information, it in no way claims to be the best, or even the preferred method to achieve the desired goal mentioned in the description. It is just a technique I use and wish to share.

4-It is NOT meant to discourage, much less replace, the use of commercially available products. In fact I HIGHLY recommend purchasing and using commercial products thereby keeping these people in business. It's a small market, and many of them are personal friends.

One more thing, don't ask for links or part numbers where I got this, that is up to you as well. I just point the way. If you are dedicated and intelligent enough to successfully run an RC Sub, you’re smart enough to do some research. It’s half the fun.

So the "Beer Keg Charger Regulated CO2 Dispenser 0-60 PSI" came with a pressure dial, which promptly quit after adjusting the pressure. Started at 344.7kPa [50psi], rolled it back to 206.8kPa [30psi], and it stuck there despite any prompting, tapping, or cursing. Don't really care because after I set it, I planned to remove it anyway to save room.



I also discovered two things:

1-The brass fitting going into the Aluminum housing is held on with Red Loctite, I ended up destroying the Gauge in my effort to remove it. The 11 mm crescent wrench stripped the nut, so I had at it with a Dremel and an oversize carbide blade. I cut at the gauge side of the nut as close as possible to it and was then able to get an 11 mm socket on to remove it. But it was tough. Needed a vise with a towel to not mar/damage it to get it off. Used an 11mm socket which, accompanied by some grunting and colorful metaphors, worked. The only disappointment afterward is that it had no blood.

2-That fitting is NOT an NPT thread, so my initial hope for a brass pipe plug was "no go". So I took out good old JB Weld, filled the small hole in that brass fitting, smeared the threads as well and screwed it back on with the socket. For good measure I coated it with the rest of the leftover JBW. Left it to cure for 24 hours. Belt and suspenders. That port is now permanently closed.

A day later I tested it at the pool using the Freon system I pulled from the 591. All I really needed was that valve extender on her home-grown freon tank. The rest was left connected to keep it together in case I needed to reinstall it. I can use a tire gauge to set the pressure and also test the "blow" in a pool as I use Schrader valves in most of my boats as a mechanical gas release valve. My Vent/Blow setups are standardized throughout my Fleet.

Since I plan to keep it in the "wet" when in use, I also modified the regulator further by:

1-Wrapping the gap with self amalgamating silicone tape between the adjustment knob and the body after setting the working pressure to prevent water ingress to the internals. Doubt it's stainless and I don't want corrosion. Plus it keeps the knob from accidentally turning and changing the pressure setting. After a few times of use and seeing that nothing changes, I can then go with large size moisture proof Heat shrink for a permanent solution.

2-I covered the small breather hole on the body with a piece of electric tape for the same reason. Did not seem to affect operation even a 1m [39"] deep.

3-I discarded the outer housing of the 3/8" Threaded adapter and kept the inner part with its o-ring. I opened up its thru-hole to accept a 10-32 tap. I then attached a 1/16" barb/10-32 threaded adaptor fitting to accept the 1/16" ID Clippard hose I use. This is then threaded back onto the regulator where the 3/8" adapter goes.

The pressure hose then goes to a self-sealing, quick disconnect. The other side will plumb to the Schrader valve that's operated by a servo to blow the ballast tank.

Why?

The reason I plan to keep it in the wet is so that it's quickly removable to save room and easily replace the cartridge too. Make a mount for it and keep it in place with a rubber band or a clip. JUST had an amazing idea regarding mounting it, WTC’s, and items needing easy removal! Thanks for making me write this!! (That will follow)

Also I can share it among several boats. Why build more than one, or perhaps only a second as a backup? The more you have, the more that needs care and feeding. But things always seem to fail after driving two day’s to a major RC Sub show, a backup would be good. Don't need to make one for every boat.

The self-sealing, quick disconnect lets it hold its pressure when swapping between models. Also if you want to weigh it. More on that in a moment.

So here’s what I discovered poolside.



Using an inverted container devoid of air, I was able to completely fill that container 7 times, with an 8th blow filling it 20%. Again the Regulator operated normally at a depth of 1m [39"] with the breather hole taped.

That container holds 1.1 liters [67.13 Cu in] of water.

Giving a total blow capacity of 1.1 * 7.2 = 7.92 liters, or 7920cc [483.30 Cu in]

20cc/cartridge gave us an expansion ratio of 396:1

The 591’s ballast tank has a volume of ~1313cc [80.12 Cu in]

So that means I’ll have approx 6 FULL blows (7920/1313=6.03)

So is that good for a $1.60 cylinder? Better or worse than Propel or the less expensive Freon??

Here’s what one needs to consider…..

1-Is it your primary surfacing method or backup?
For me it’s my backup. I’m normally at PD so I use the snorkel with a diaphragm pump to induct air. ONLY if the snorkel can’t make the surface, or I want to impress the nerds, do I blow the tank. Of course the failsafe on a delay of 9 seconds does it too. So I conserve my “gas”. Also, since I only need to get to PD if I dipped below, I may not need a “full “ blow, just enough to get the Snorkel out.

2-It’s consistent.
I always know the tank starts out full when I replace the cartridge. No having to charge, chill, charge and waste gas. I hated filling my tank. I could never be sure how much I started with for the day. The amount of gas liquid gas onboard affects your submerged trim.

3-It is easy to check its volume.
Just weigh it on a portable scale. SO all you have to do is after you put in the very first 16gm cylinder, weigh the whole assembly. An empty cylinder has an initial weight minus that 16gm! Remember it’s ok due to that self sealing quick disconnect! You can pull it any time to check the gas. Portable lightweight scales on Amazon are CHEAP!

4-You can adjust the flow.
Normally the Freon/Propel boat operates in the range of 482.63kPa [70psi], I always had a “violent” blow, wasting gas. Granted we could get to ~50m [165’] before the water pressure would overcome the gas pressure, but I ain’t going THERE even if the signal could reach it! Regulated to 206.8kPa [30psi]. We could still theoretically get to 20m [65’] and blow the tank. Bravo Zulu to you if you reach those depths before a LOS event! I consider 1m [39"] as my normal “Test” depth as it’s the standard for IP ratings, anything below that is “Deep Submergence” for me.

IE: Regarding the 591’s usage of 6 complete blows: 16/6=2.66gm per FULL blow. So if it’s ~ 8 grams lighter at the end of the day, I should have 50% capacity left.

I’ll have it installed over the next several days in the 591. Bob Martin is coming up next weekend to run with us “North Texas Model Shipwrights” so he’ll be on hand to test it with me. I’ll do a follow up with install pictures, performance and grab some video. No doubt Bob will too.

Only time will tell over the season of use to see if it saves anything. At the very least I think it would be the convenience in installation and use (don’t have to make your own tanks for the folks who build their own), as well as peace of mind with this system. I often find the cheapest is not the best value.

Weight of the system with a full cartridge.



Weight of the system with an empty cartridge. 205-189=16gm’s!!

[redboat219]

Bob showed a CO2 system a while back

[redboat219]

How about the Green gas used by airsoft/paintballers.

[Bob Gato]

Yes believe it or not propane is one of the few fuels that are not considered greenhouse gases... And I believe propane is cheaper than anything in use in model subs right now it's just that people are afraid of the explosion Factor...

[wlambing]

But then Ed would have to NOT have a cigar anywhere near his boat! That might be tough for him!! ;)

[redboat219]

But then Ed would have to NOT have a cigar anywhere near his boat! That might be tough for him!! ;)

[QuarterMaster]

Bob showed a CO2 system a while back

BOB! You didn't mention this setup all the time I was yaking about it!! We even discussed my corrosion concerns!!

What gives? Is that system you tested in the tank showing signs of degradation?

Anyone purchase it?

ANY feedback?

Yes believe it or not propane is one of the few fuels that are not considered greenhouse gases... And I believe propane is cheaper than anything in use in model subs right now it's just that people are afraid of the explosion Factor...

I was actually thinking butane, easily found, filler valves are available and easily integrated, fairly low PSI (2 bar??)

But then Ed would have to NOT have a cigar anywhere near his boat! That might be tough for him!! ;)

Other than the "legal ramifications" in a very litigious society, the only issue I see is testing at the bench, or pondside during a "Rig for Dive" evolution. Will the ballast tank reach a stochiometric level within the Ballast tank? Butane is heavier than air, Butane is not lighter than air. Butane gas is 2.08 times heavier than air. Butane weighs 2.5436 kg/m³ whilst Air weighs 1.225 kg/m³ (15°C at 1 atm). Therefore the gas would disperse quickly exiting through the flood holes. So I would think it not an issue.

FOR THE RECORD!

We're already using it!!

The Danger of Aerosol Can Propellants
Many aerosol cans use propellants that are some combination of butane, isobutane, and propane. These are flammable and require special care when storing and in use.

See attached data sheets! (Don't any other F#¢%ing nerd out here read their SDS's??)

FWIW, I only light my stoagie when "Underway, making way"

Thew more I think about it, the more I'm liking butane!

[trout]

Big badda boom!

[redboat219]