Double tanks

[CaptnJack]

A 3500W generator won't start any portable electric compressor. It would run it sinec they draw about 14amps @ 220V, but the starting load is going to be far too big.
Gas engines = CO which is really bad. Getting an electric unit for home use and more tanks is typically much faster and easier since the 3.5cfm portables are both loud and slow. Too loud to run at a campground or motel.

[Jeff Pack]

FYI 1 hp is about 2kw.

I think my Bauer Capitano is a 5hp electric, so that makes one big ass generator you'd need, to include start up spikes as well.

[Jeff Pack]

On thedecostop a guy selling a RIX compressor has a mixing stick for sale as well.

Someday I hope to have one. While electric makes sense when you live in the area you dive I would prefer one you could run off a 3500 watt generator (I have one) or off a gas motor so it would be portable.

I see the one you are talking about is in TX, guessing shipping on that is not cheep.

get his reg and mixing stick for your setup!

[Nwcid]

As I said I hadn't really looked into them yet so was not sure on the motor size. That is obviously too big to easily run off a generator.

Good call Jeff. I will email him.

[Desert Diver]

FYI 1 hp is about 2kw.

I think my Bauer Capitano is a 5hp electric, so that makes one big ass generator you'd need, to include start up spikes as well.

1 HP is 746 watts. Actual running would be more like 1000 watts. Starting? Well it depends on the motor.

[LCF]

Personally, I prefer the Worthington 85s to the Fabers. The Fabers are much more butt-light, and they are also floatier. I found that out the hard way, when I borrowed some . . .

[Jeff Pack]

FYI 1 hp is about 2kw.

I think my Bauer Capitano is a 5hp electric, so that makes one big ass generator you'd need, to include start up spikes as well.

1 HP is 746 watts. Actual running would be more like 1000 watts. Starting? Well it depends on the motor.

oh crap, I've had that number stuck in my head for years.

[mpenders]

Yes, when full, she should have no trouble sinking - but (just for argument's sake), let's say that her HP100 is negatively 2lbs buoyant when "empty", and the LP72's are negative 1lb each when "empty" = she gets to wear the same amount of lead (not figuring in weight related to bands/valves/manifold).

What 72's are -1 when empty? Both sets I have float when you get below 1000psi in salt water.

Those numbers were just generalizations without any specific tank being considered. The emphasis was on understanding the math for additional lead weighting considerations.

However, most info I find on steel 72's show them to be negative in sw. Never having dove them doubled up (yet, anyway), I really can't comment on your experiences.

I have a couple old 72's, including a 1962 USD, and one that used to be my dad's, labeled White Stag, born 1972 - which I use mostly during pool sessions when teaching. It is definitely not positive when empty, but I really don't know it's exact spec's. The info I've found on the Scuba Pro Slim Line 72 indicates it should be -2.3lbs when empty. The cute little steel Slim Line 60 next to it is supposed to be -2.5

My Faber MP 72's (rated 3000+10%) are listed at -6lbs each when empty in sw.

[CaptnJack]

Personally, I prefer the Worthington 85s to the Fabers. The Fabers are much more butt-light, and they are also floatier. I found that out the hard way, when I borrowed some . . .

+2 lbs from the Faber to the current crop of Worthington lp85s. The older painted ones like you have seem to have been heavier, but that doesn't seem to be reflected on and tank charts I have ever seen.

Butt light is generally good since that's where we want to put lead by and large. And bioprene of course :p

I'm not a fan of manifolded lp72s, not for trim issues or anything like that. They are just too darn small for be useful for me. A single 130 is way easier to manage, lighter, and stows on the boat easier. Doubles lp72s are really just enough gas for 1 long dive so why bring all that bulk? Then again I am generally not a fan of diving doubles recreationally anyway. After 2 spine surgeries I think people need to remember spines have a finite life span and it can be less than a diving career if you decide to get all techy for no real reason.

[mattwave]

Then again I am generally not a fan of diving doubles recreationally anyway. After 2 spine surgeries I think people need to remember spines have a finite life span and it can be less than a diving career if you decide to get all techy for no real reason.

Been saying that for years...well except the surgery part, which I would like to avoid

[Joshua Smith]

if you decide to get all techy for no real reason.

Lot of that going around, I hear.

Made me laugh.

[Nwbrewer]

Yes, when full, she should have no trouble sinking - but (just for argument's sake), let's say that her HP100 is negatively 2lbs buoyant when "empty", and the LP72's are negative 1lb each when "empty" = she gets to wear the same amount of lead (not figuring in weight related to bands/valves/manifold).

What 72's are -1 when empty? Both sets I have float when you get below 1000psi in salt water.

Those numbers were just generalizations without any specific tank being considered. The emphasis was on understanding the math for additional lead weighting considerations.

However, most info I find on steel 72's show them to be negative in sw. Never having dove them doubled up (yet, anyway), I really can't comment on your experiences.

I have a couple old 72's, including a 1962 USD, and one that used to be my dad's, labeled White Stag, born 1972 - which I use mostly during pool sessions when teaching. It is definitely not positive when empty, but I really don't know it's exact spec's. The info I've found on the Scuba Pro Slim Line 72 indicates it should be -2.3lbs when empty. The cute little steel Slim Line 60 next to it is supposed to be -2.5

WP_000665.jpg

My Faber MP 72's (rated 3000+10%) are listed at -6lbs each when empty in sw.

WP_000666.jpg

I only dive them sort of doubled (sidemount) but they definitely start to float away from the rear D-rings when they get below 1000 and I have to move the clips to the front D-rings. Next time I dive in the daylight I'll take one off entirely and see how it floats.

[mpenders]

I only dive them sort of doubled (sidemount) but they definitely start to float away from the rear D-rings when they get below 1000 and I have to move the clips to the front D-rings. Next time I dive in the daylight I'll take one off entirely and see how it floats.

Interesting - old school steels 72's, right? Wonder if they just get butt-light? It's not easy to track down published buoyancy specs on those, and the general consensus I've read is that they're thought to be around -1lb.

I have 2 of the slim 72's, neither of which I've dove. It looks like the previous owner had them setup as stage tanks. They are MP tanks (3000+10%) with an outside diameter of 6". I've held onto them with the thought that they might make great sidemount tanks...someday...

[CaptnJack]

I have 2 of the slim 72's, neither of which I've dove. It looks like the previous owner had them setup as stage tanks. They are MP tanks (3000+10%) with an outside diameter of 6". I've held onto them with the thought that they might make great sidemount tanks...someday...

They are except for being so darn tiny. LP45s are even better but diving 1/4ths to 1/3rds there just isn't much gas to work with unfortunately. Both are the bees knees for poking into unknown caves, which are unfortunately many hours of driving from here :(

[Nwbrewer]

I only dive them sort of doubled (sidemount) but they definitely start to float away from the rear D-rings when they get below 1000 and I have to move the clips to the front D-rings. Next time I dive in the daylight I'll take one off entirely and see how it floats.

Interesting - old school steels 72's, right? Wonder if they just get butt-light? It's not easy to track down published buoyancy specs on those, and the general consensus I've read is that they're thought to be around -1lb.

I have 2 of the slim 72's, neither of which I've dove. It looks like the previous owner had them setup as stage tanks. They are MP tanks (3000+10%) with an outside diameter of 6". I've held onto them with the thought that they might make great sidemount tanks...someday...

Maybe they do just get really butt light. I'll try floating one and see what happens. I have 4 now, and none made after 1976 I think. I think 3 are USD, one is unknown.

[ArcticDiver]

Personally, I prefer the Worthington 85s to the Fabers. The Fabers are much more butt-light, and they are also floatier. I found that out the hard way, when I borrowed some . . .

+2 lbs from the Faber to the current crop of Worthington lp85s. The older painted ones like you have seem to have been heavier, but that doesn't seem to be reflected on and tank charts I have ever seen.

Butt light is generally good since that's where we want to put lead by and large. And bioprene of course :p

I'm not a fan of manifolded lp72s, not for trim issues or anything like that. They are just too darn small for be useful for me. A single 130 is way easier to manage, lighter, and stows on the boat easier. Doubles lp72s are really just enough gas for 1 long dive so why bring all that bulk? Then again I am generally not a fan of diving doubles recreationally anyway. After 2 spine surgeries I think people need to remember spines have a finite life span and it can be less than a diving career if you decide to get all techy for no real reason.

Y'all know about my saga. One of the Important things I have learned is how vital it is to take care of your bones. I have met so many people who did not and now have no hope of anything like a normal future. The key seems to be proper diet, lots of weight bearing exercise, but not to failure point, and overall fitness. When the trauma comes it is too late then to get good bones; they are the product of years of attention.


Personally, for doubles I like HP100s the best although I've used 120's a fair bit. Since I travel to dive most of the time I also twin up Al80s. Actually those turn out to be pretty good even if marginal for really long or deep dives. Of course LP85's overpressured work well too. Guess the bottom line is that they all work for someone for something. A person just has to experiment a little to see what they like best and is most suitable for that individual.