Portable Compressor/No Experience

[rcontrera]

All good advice. If you are thinking about buying a compressor only to save money, you are making a big mistake.

Assuming you purchased a brand new Coltri personal sized compressor, the filter cartridges will cost you about $1.10 per fill. The oil is $12.95 per change so that adds another $.25-.30 per fill. The 100 hour maintenance kit is $150 so there is another $.50 per fill. With care you can expect 1000 hours of runtime before having to do any major work so, assuming $3290 for the compressor, that adds another $1.10 (about) per fill. So we are looking at about $3 in actual costs for each fill and I am sure that I am missing something ... like gas or electricity.

Is it less than the $7 plus travel costs you are paying now? Absolutely!! But you have to do a LOT of diving to justify the up front expense.

While I would love to sell you a new compressor, I think that having a half dozen or more tanks would be a better first step. Then, if you find you still need to think again about the compressor, you will have some firm number to work from as far as how many dives you do per year.

Hope that helps!

 

[oxyhacker]

Ray, have you ever talked to Coltri about putting a bigger filter stack on the MCH6? Those tiny standard $40-$50 cartridges just don't last very long, and really run up the cost of operation. OK maybe when they didn't use anything in them but charcoal (which I gather they still do in Europe!) but borderline adequate now that they are expected to hold a molecular sieve and CO catalyst too. It would be an easy upgrade that would considerably improve the usefulness of the compressor.

We have modified a few MCH6s over the years with generic stacks that take the short Mako cartridge. Filter life is increased seven fold, and the cartridges cost the same or only a few dollars more.

Assuming you purchased a brand new Coltri personal sized compressor, the filter cartridges will cost you about $1.10 per fill.

 

[rcontrera]

Actually that was one of the first conversations I had with them when I became a distributor. The way it was explained to me was that the MCH6 target market was cheap and lightweight and for the individual diver. Adding in that short Mako filter is neither cheap nor lightweight.

When I sell one of the little guys, I always make a filter upgrade available at a very good cost, but nobody, out of over a couple of hundred sold, has taken that option. In fact, I have only sold a handful of upgrades in total.

Most serious compressor owners take the next step up in compressor size and that also comes with a 9000 cubic foot filter system. I am actually kind of amazed at how many home systems I have been selling lately that are far superior to most dive shops.

 

[IRONMANO12]

WELL I PART OF THE WAY LUCKED UP HERE, I'M A FIREFIGHTER AND AT WORK WE HAVE A COMPRESSOR. THAT'S KEEP UP TO DATE WITH SERVICE AND ANALYSIS TEST THAT GIVE US THE BREAKDOWN OF OXYGEN, CARBON DIOXIDE, ANY ODOR, CARBON MONOXIDE, OIL VAPORS (Hydrocarbons), OR ANY PARTICULATE MATTER. SO HAVE A GOOD DEAL AS FAR AS THAT GOES.

BAD NEW THE CITY I WORK IN IS ABOUT AN HR FOR ANY DIVE SITES. SO HAVEN TO BORROWING TANKS TO EVEN HAVE GONE AS FAR AS USING MY DOUBLES AND A WHIP TO FILL MY 80s OR TOP-OFF.
BUT WHAT IM LOOKING FOR IS GOOD WAY AND ALL THE PIECES AND PARTS TO BANK AIR IN A SOMETHING LIKE A 6000PSI DOT FOR THE DAY THAT I'M DIVING, AND THE RIGHT BOOSTERS, MONITORS AND PURIFIERS FOR NITROX, SOMETHING I CANT FILL AT WORK.
YEAH I KNOW THIS OPENS UP A HOLE NEW BALL OF WAX
FOR HOW IS ALL OF IT GOING TO WORK TO WHERE AND HOW I GOING TO GET IT BACK AND FORTH TO AND FROM THE DIVE SITE.

ANY ONE HAS ANY IDEA I WOULD LOVE TO HEAR THEM...

 

[oxyhacker]

I figured you'd probably have asked. I'm not really advocating a Mako-sized stack, but I think something with say, 2 or 3 times the capacity of what they are fitting now, wouldn't take up too much more space, nor cost all that much much more to make. Certainly it would be much cheaper than retroactively upgrading to a aftermarket housing.

I think one problem is that people who buy the little Coltri are usually trying to put a fill station together on the cheap, and don't realize how important a good stack is, and how irritating the little Coltri stack will become.

Actually that was one of the first conversations I had with them when I became a distributor. The way it was explained to me was that the MCH6 target market was cheap and lightweight and for the individual diver. Adding in that short Mako filter is neither cheap nor lightweight.

 

[james croft]

Another option would be to invest the compressor $$$ in a rebreather and not worry about buying a bunch of air.

 

[rcontrera]

I figured you'd probably have asked. I'm not really advocating a Mako-sized stack, but I think something with say, 2 or 3 times the capacity of what they are fitting now, wouldn't take up too much more space, nor cost all that much much more to make. Certainly it would be much cheaper than retroactively upgrading to a aftermarket housing.

I think one problem is that people who buy the little Coltri are usually trying to put a fill station together on the cheap, and don't realize how important a good stack is, and how irritating the little Coltri stack will become.

Well ... there's the rub. This little guy was only meant to be used to fill individual tanks right off the system at the absolute lowest dollar level possible. As I said before, someone putting together a real fill station will go with a $6600 compressor instead of a $3300 one.

 

[frogman62]

Ironman,

Look at my web site < sheldensportinggoods.com >
I have been building compressors for over 40 years with Military Kidde conversions. IF you read more on scubaboard -- you will find several members who have my compressors. Priced at less than $3000 for 4.2 cfm to 4500psi with mako/bauer stacks and better than grade E air - they are filling multiple storage tanks with air and nitrox.
I've sold 26 compressors in the last 16 months for diving , paintball and HP airguns
Give me a call at 316-992-0505 or PM me and I give you several very satisfied customers to talk to.
Jim Shelden

 

[spoolin01]

I'm an amateur at this, but I've had a gas-powered Rix SA-6 oil-less compressor for 4 years or so, do maybe 20-40 tanks a year, and there's nothing about it that I don't prefer over going to the LDS (well OK, the noise, but that's more an issue for the neighbors, I've got ear muffs). All I can think of for overhead was a grease cartridge and <$100 worth of filter elements - moisture and CO. The CO is probably not needed, but just starting out I wanted to be sure. And gas. I don't track the gas cost but it's got to be on the order of a quarter or two per tank. I love the convenience, the full fills - I can't even get the LDSs to fill AL80s to 3000psi cold here, forget about a proper HP fill. I can store the tanks the way I want during the off season, and top them off if I borrow some air for some garage use, or give them a couple psi extra for the dive. If I drain one to look inside, swap or rebuild a valve, there's $4+ it doesn't cost me per tank. It hasn't dragged me into mission or technology creep, but those are semi-peripheral to the basic cost-benefit assessment anyway.

It may be a wash regarding cost per tank with some compressors (esp the oiled kind), but if you buy a half dozen tanks as an alternative, with vis and hydros you've doubled your cost per dive unless you really dive a lot.

You can get Rix's for $2-$3K used, they'll pump an AL80 in <15 min, and they hold their value. Probably true of many other brands too. I'd get single phase electric if I had it to do again.

I don't know if I'll save money in the end, but it's sure close enough that I don't care, the convenience is more than worth it.

 

[iDive Florida]

I've noticed only one person has really touched on the convenience issue with a compressor. Unless you have a 24hr Dive Center on the same street as your house, it is a HUGE pain picking-up and dropping-off tanks, especially with the finicky hours of most dive shops. Buying a lot of tanks is probably the best alternative. But refilling your tanks even with a slow compressor is not bad since you can do it while doing other things within the vicinity (washing your car, dive gear, cleaning garage, etc.)
Someone did the math on what it costs to run and maintain a compressor vs. price of fills. Think about lugging tanks in your car, truck, or SUV down to the dive shop with gas costing $2.50 - $3.00 per gallon, plus wear and tear on your shocks, transmission, racking up mileage. Not to mention it's one extra haul on your back.
I had a little portable guy a few years ago, and it saved me so many spur-of-the-moment dive trips, and so many annoying trips to the local dive shop. It's a little work to maintain from time to time, but you can do on your schedule, not a dive shops.
If you have a good hunk of extra money, get one. If you have a little extra money, get a handful of tanks like someone back in this post suggested.
Know the over-arching costs, but don't forget that saved hassle/convenience has a price, too!
Think how much money on gas and maintenance you would save if you never bought a car and just went everywhere on a scooter... always. Everywhere. For everything.


-Ken
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