Old/New CO2 system still available?

[sgtmac1]

I note that the SCR, Fall 1992, Issue 10 had a 4 page article on building and using a CO2 gas ballast system which included parts needed and related costs. I was wondering if the information given was still valid and if others in the Subcommittee had tried this system. The article was by John C. White and Cliff Shaw.
I was going to replace the pvc tank in this early Merriman wtc with a copper one and use CO2 to raise this big boat. Any thoughts?
Thank you.

[JWLaRue]

I was going to replace the pvc tank in this early Merriman wtc with a copper one and use CO2 to raise this big boat. Any thoughts?

Not sure if this is what you meant, but just in case......Going with CO₂ will require a proper DOT-approved holding container....you don't want to build your own copper tank using the usual plumbing parts! The pressures involved with CO₂ are far higher than the Propel that we use in the typical gas ballast system. You don't want to create something that will blow up in your face.

-Jeff

[Ralph --- SSBN 598]

Information.......

At room temperature .........
CO2 in cartridge is at 800 to 850 psi in a compressed gas state.
Canned Air or Propel is at 71 psi in a liquid/gas state.

In the late 80s I remember seeing boats destroyed and a few injuries do to CO2 system failures.
I can not think of a Propel failure though I would think they have happened do construction of retention containers or poor plumbing.
I just can't recall any.

[salmon]

You will not be using a copper tank for CO2, that is only good for Propel systems. The CO2 systems use the 12 gr (http://www.walmart.com/ip/Crosman-12...-15ct/16662954) or 90 gr (http://www.pyramydair.com/s/a/Air_Ve...osable_2pk/336) cartridges. Mikesubworks used to have the complete system, but I think most people have stayed away because of the extreme pressure already expressed.
So do not make this harder on yourself, go propel first. After awhile you can "upgrade" or better term modify your wtc for CO2.

[southern or]

800+psi is high grade stainless steel range with a pretty beefy flow regulator. I'd listen to these guys. In the event of a malfunction you'd have a pipe bomb, a rocket, or both and copper isn't used for high pressure because it's just too soft. To kind of put this into perspective, this is a photo of the superheater pipes for the SP&S 700, and she's only rated to 260psi. The other pipes are for the flue.

[JWLaRue]

So to answer your question....the system described in that article is still a very viable design. Whether the individual parts are using the same part numbers is something I cannot answer.

It's not something to take on lightly due to the very high pressure involved. Even when constructed and used properly there can still be problems. There are a couple of us who have witnessed what happens when the burst disc goes and the surrounding effects.

That said, there are some good reasons for choosing to use CO₂. You would get many times the number of ballast blows for a given storage bottle than you will when using Propel. Also, the change in weight per ballast venting is extremely small so you won't see as much change in the trim of the boat as you use up the gas. For the larger boats that require larger ballast tanks this cane a real benefit.

-Jeff

[sgtmac1]

Are these bottles tested for pressure?

Found these at a local farm store for co2 powered paintball guns. They come in various sizes. Are these tested and safe to use as storage tanks for co2? I've never done any paint ball stuff, so hopefully someone can advise me on their use.
Also, these were given to me as a gift when I expressed an interest in using co2 in my sub-are these safe to use with the proper regulators?
Thanks
Dave

[JWLaRue]

Those CO₂ containers look like they should be okay. If they are you should be able to see DOT markings on them......

-Jeff

[thor]

If you have no experience with Co2, stay away from it!!! It has tremendous amounts stored energy and should be used only by qualified, experienced individuals. You are not just storing gas, you are storing liquid and vapor. If not handled with great care and knowledge you can suffer extreme injury and even death. There are much safer alternatives for operating large boats. There is a reason why these systems are a rarity. Ask Gene Berger.

[Guest]

Have you considered retrofitting the cylinder with a low pressure air pump, like Dave Merriman does on his current range of WTC's.

There's no real risk with these systems, and they're straightforward and inexpensive to maintain. You can purchase pumps on ebay for peanuts these days. They weren't available years ago, but these days they're two a penny. To get reasonable pump times on a big tank like that you would want a larger pump.

e.g. http://www.ebay.co.uk/itm/1PCS-DC6V-...kAAOSwyQtVmJOU

Specification of above pump can be found here-

http://www.wwwe.koge.com/index_down.php?openCatIDfor3=1&openCatID=1&CAhs=defuse&ISPID=52&IIBig=1&sele=shopbig_dm_down

As you can see it will pump out a litre of ballast in about 13.5 seconds. If you want a faster pumping rate, you can look for a larger pump, or fit a pair and run them in parallel.

[Guest]

A very large pump. This would suit just about any big boat. You could reduce the size of the pump by retrofitting it with either a smaller brushed motor, or perhaps a brushless equivalent.

http://www.ebay.com/itm/12V-DC-Diaphragm-Vacuum-Pump-Air-pump-High-Pressure-Micro-Vacuum-Pump-/291600718858?hash=item43e4c1dc0a:g:ZvMAAOSw~bFWFpIC

[bigdave]

I have a few of the low pressure systems and they work great.
Good way to go with a big boat.
I also have a Co2 system in my Ray Mason Nautilus. I have the system Mike's Subworks sold.
I used a 4 OZ paintball gas cylinder.
It was/is a great operating system. But sadly I have not had the sub out of its case in 6 years.
It was getting hard to get my Co2 bottle filled. Plus your bottles have to be up to date on pressure testing.
Jim Butt fills his own but I am not that brave.
I have seen and heard what can happen if a burst disc pops.
The guy in the sporting goods store had just finished filling my bottle and set it in a safety box to let it rest.
We started talking about model subs and BANG!!! WOOSH!
Loud! Whollycrapola.
He then told us why he puts them in the safety box as one time he was setting them on the glass case till one went off and shattered the case.
As Matt mentioned one blew up on Gene Burger and took out his toolbox.
Jim Butt had the front end of his Batfish blown off. I have seen the video.
Quite impressive but not funny at the time.
We are just saying use at your own risk and be careful. BD

[sgtmac1]

More research

So, you would add a pump to the water tank and use a Propel tank for emergencies? Using just a pump, what kind of scale depth control would take place on a 6-7' sub, weighing approximately 25#? These boats were at the Carmel meet this year and are probably in the same size as mine will be-would a pump do a good job getting them up?

Checked the local paintball place today-they have 8oz tanks that they use for the pb pistols, they fill the tank up with 3000psi air(not co2)and regulate it down to 850psi to ensure accurate and limited pb performance. No known accidents, tanks have to be pressure tested every 5 years, small tanks are $40, and the largest ones are $55 to $153, depending on whether they are made with steel or carbon fiber. Research continues.

[sgtmac1]

Ordered 3 different pumps from ebay, all from China. Be a couple of weeks till I can report on their functionality...

[bob_eissler]

I have air tanks with my pellet guns. They inspect with a boroscope and pressure test. Any corrosion makes the tank uncertifiable. They won't rebuild the cylinder when the seals get old either. But that is much higher pressure than co2.