New compressor buyer

[jbscuba]

Hello to all,
I am new to buying a portable compressor for my garage. I have researched Coltri, Alkin W31, Nardi Atlantic, Bauer Jr and Kidde electric compressors. Any info on comparisons would be helpful.

 

[cbmech2]

I just took delivery of my custom system that includes a Coltri MCH-6/EM. I did my homework and found that everyone who owned the Coltri had been more than satisfied with it. I just filled my first tank yesterday and have no complaints. It is competitively priced, has a good reputation, a good support network for parts and it very compact. My vote is for the Coltri.

 

[psychocabbage]

We have been looking into systems for the past few months. We are tired of paying $5 a fill and having to lug the tanks to and from the shops when we can get our own home use unit and do it that way.

At $3K for a home unit, its not cheap but from reading a few posts here, are we buying into a small engine/compressor repair hobby? Why are the parts so important? I guess I am so used to the standard air compressor in shops that never fail. Are these things much more finicky? Should we be looking at $5k and up units instead?

 

[cbmech2]

PC, I don't think you are if you purchase a quality system and keep with the preventive maintenance. The system I bought that I described above is a personal (garage) system that includes a 395 cf storage tank. The tank will provide more than enough air to fill one tank at a time and give me the ability to use my test bench simulataneously. I simply do not need that much capacity because I am not constantly filling multiple tanks at the same time, using LP air simultaneously and keeping a cascade system topped off. I would think that you buy to your planned air capacity needs and investing into more compressor than you actually need is a waste of your money.

 

[webbedfoot]

I own an Alkin w-31 electric and it works great. The 31 was made to go head to head with the Bauer Jr. So either will do if that is the direction you choose.
Small CFM units like these take like 20 or more minutes to fill even 72's and must be drained (inlet filter and air filter) about every 15 minutes. So if you want to get into a dozen or so fills every week (like I am doing for my dive classes) you will find yourself very soon wanting to cascade large tanks and outfitting your unit with an auto-drain timer. Now you're looking at big bucks!
If it's just for recreational convienience, buying several more Scuba tanks and filling up at the dive shop could be the smartest and cheapest way to go.
Well anyway, the best of luck,
Webbedfoot

 

[frogman62]

Please check my web site if you haven't already <sheldensportinggoods.com> . The kidde compressors are better manufactured than any commercial machine in the 3-5000PSI range New to the US goverenment these sell for $5000 to $18,000 for the bare compressor are are used in the most demanding weapons system and aircraft built today. I have a guarantee that no other supplier will consider. IF the compressor head fails to operate in the first year, I'll send you a loaner in 48 hours or less and fix yours for less than $250 including shipping. I have sold over 400 units to scuba shops, fire departments, paint ball fields and air gunners and haven't needed to utilize the guarantee more the 10 times in over 30 years.
Jim Shelden

 

[Jimmer]

Jim,

I'm not in the market right now, but would eventually like to have my own home compressor. What would you recommend for something that I could continuously blend nitrox/trimix with, and fill banks? I dont need anything huge as it will be for personal use, and at a residential location, so I wouldn't have 3 phase power.

Thanks,
Jim

 

[frogman62]

Jimmer, I have sold these 4 cfm compressors for 35+ years. They are in daily use in fire departments (now mostly small cities and rural fire districts, but for the early years in multiple fire stations in cities like Wichita, KS where I live) they are in scuba shops , on dive boats, and for individuals pumping nitrox up to 40% and mixing trimix. I owned two different dive shops and taught (YMCA gold star instructor and PADI) from 1968 to 1986 and used a pair of these compressors and 6 - 330 cuft storage tanks supporting 250 students a year and 5 instructors during the last 5 years before I sold the shop. These compressors support very active paint ball fields and on a good weekend will run for 3-7 hours a day. I also have the air gun groups using my compressors at 4500 PSI. I have sold 26 compressors in the last 9 months since I started the web site. These are very good compressors and I have boxes of spare parts (new and used)to support these units. I started diving in 1954 and built my first compressor while in Ottawa University in 1957.
Jim Shelden

 

[Doc Harry]

What is your budget for a compressor? Plan to spend twice that when it's all said and done.

If you need a home compressor, do you also need to maintain your own cylinders? Add in the cost of training, tools and supplies for that.

Are you going to be mixing Nitrox? Add in the cost of analyzers, oxygen, cleaning, etc.

How are you going to verify the quality of your breathing gas? How are your going to check for carbon monoxide? IF you are going to use a gas-powered portable compressor, you've got to check every cylinder for carbon monoxide. How many filters will you use? Do you have a gas lab picked out yet?

I have an Alkin W31. It is among the cheapest of the smaller compressors at about $3,000. Works great. Also runs at a relatively slow RPM. The US distribitor of Alkin, in the other hand, not so great.......):

As far as continous blending is concerned, are there any small compressors in the USA that are approved for blending up to 40%? It's common practice to do CB, but do any manufacturers actually advertise that their compressor is approved for CB up to 40%?

I have been blending Nitrox with my Alkin W31 for over a year now without any issues. I change the oil more frequently than recommended and check each cylinder for carbon monoxide. So far there have been no issues.

The Alkin advertises that their compressor is approved for continuous duty. I never run mine for more than 60 minutes at a time, but do regularly crank my storage bank up to 4,400 PSI.


Good luck!

 

[frogman62]

Most of my SCUBA users have several thing in common. They do continuous blending 28,30 and 32%. They 2-4 storage tanks. They are primarily electric compressors. They test their air at least once per year( I recommend they do it once 75% toward the end of a filter cycle to see if they should change soon than manufacturer recommends) Always use a filter cartridge on the last filter that has linde 13x, hopcalyte, and activated carbon (XCAC). most have two filters:
1st. moisture trap with linde 13X and 2nd. XCAC config. They don't ofter use trimix but if they do -- partial pressure blending. Change oil every 35 hours run time ( average is 3-4 times a year). Compressor use is 150 to 300hours. Use 300-400 tanks of air /year (doubles and multi dives and have other divers that they share air with).
Paint ball and air gunners are different. They run lots of hours, support teams or commercial fields with less 150 players on week ends. Have 4 - 8 storage cylinders. FIlters are larger or 2 chambers and only have linde 13 X. Change oil every 50 hours but run much longer times per use, 5-6 hours at a time is common at 3000 to 4500PSI. Don't test the air and usually dry and reuse linde 13X.
Fire departments are small locations now and usually test air 2 times per year at filter change. Run less than 100 hours per year and do some training with Scott air packs. May fill all scuba tanks for divers in the fire department.
If you have questions please let me know.
Frogman62
Jim Shelden