Max Air 35

[Teller]

Does anyone have any experience with this compressor? As far as maintenance does it just need oil and filters changed? Does gas or electric offer any benefit over the other? Thanks.

 

[rddvet]

Does anyone have any experience with this compressor? As far as maintenance does it just need oil and filters changed? Does gas or electric offer any benefit over the other? Thanks.

The compressor is a rebranded Coltri MHC-6. It's a good little compressor. It's a pretty straight forward unit with minimal maintenance other than what the manual says as regular maintenance. If you're just pumping air, all you need is good oil and filter changes. If you're doing Nitrox, consider secondary filtration if you'll be partial pressure filling. If not pp filling, it's not a big deal, although I think secondary filtration regardless is a good idea.

If you're ever going to pump on the go, then gas is the way to go. If you're pumping at home and esp if you're going to be doing nitrox continuous mixing, electric is better so you don't have to move the compressor outside to run and then have long lines everywhere.

I've learned a ton recently on compressors. If you need info, rcontrera here has been exceptionally helpful and sells exactly what you'd probably be interested in.

 

[Allan C Smith]

Dose any one know what the max run time is on one of these? And how long the cooling interval is? thanks!

 

[CraigAClark]

Ray can tell you what the manual says for the MCH-6. In size it is comparable to a Bauer Jr II. Recommended 2 hour max duty cycle with 1 hour rest minimal between cycles, for the Bauer.

 

[rcontrera]

The manual is probably the weakest part of the compressor. Of the 88 pages, about 80 of them are safety, installation or maintenance related and offer no real limitations. I have never read a MaxAir manual, but I hope it is better than the Coltri factory one.

Since your compressor is used, I would just plan on assuming it was run on mineral oil and do the synthetic oil changeover routine.

• Drain all the oil out of it and inspect it for any grit or metal. Replace with high grade synthetic oil.
• Run it for long enough to get it hot (about an hour), shutdown and drain/inspect and refill again.
• Do it again at five hours and then again at ten hours.
• The manual calls for 50 hour oil change but I tell my customers 25 hours.

As for how long you can run it, that is kind of a tough one. To make these little compressors light weight and affordable, they economize by using lighter weight crank and bearings. As a result, they REALLY don't like running at high pressure for long times. On a 65 degree day you could pump one tank after another all day long with no problem. But, hook up a bulk bottle or several 80s and you may just toast it in no time.

Cop out ... I know. But just use it for what it was sold for ... a few single tank fills per day.

 

[oldtimercraig]

I've got one I bought from American Airworks a few years back (they called it a Fast35). I have had no problems to date, and it has been a great little rig to take along in the boat. The filter is awfully small, but adequate. I put a large hand packable filter in line between the moisture removing filter and the regular filter so I now just consider the original a back up. On hot and humid days the filters go pretty quick. I don't recall what the manufacturer claims the filter life is, but I would cut the time in half. It seems they were optimistic about the filter life. However, it really all depends on the humidity level. I also run mine a little slower than the manual calls for. It keeps the temp and the noise down and hopefully a little less wear. At max speed it will do an honest 3.5, maybe more, but that thing is really screaming at that speed.

Craig

 

[Herb-alaska]

Does anyone have any experience with this compressor? As far as maintenance does it just need oil and filters changed? Does gas or electric offer any benefit over the other? Thanks.

I have this compressor in gas version and love it for my use. I use it in Alaska and so it never pumps in temps to exceed 70 and most of the time it is 65 so I do not worry about heating it up. I keep the filter and oil clean and it has been good to go. The filters get a little pricey at 40 per filter and I get about 10 to 12 tanks per filter before i need to change it out. for the most part I am pumping big HP tanks and have had no problem meeting my pressure goals. One thing to take into account is that it is not fast. It will take about 45 minutes to fill a 130 that started at 500 to 800 PSI.

If I had a garage to set it up in I would have gone with the electric version but I have to haul mine in and out becasue I do not have a permanent inside location to up at. I also Try really hard to never pump in the rain and so I have 13 tanks that all need to be filled and it won't stop raining but that is not the compressors fault

BTW I bought mine from max air direct and their service has been very satisfactory

 

[rcontrera]

The filters get a little pricey at 40 per filter and I get about 10 to 12 tanks per filter before i need to change it out.

YIKES!!:shocked2: Something wrong here! I am in the Seattle area and I usually get between 25 and 35 fills per cartridge (the book says about 40 but...).

Make sure your priority valve is working. If it is OK, then you may want to do blowdowns a lot more often. You should be getting a heck of a lot more fills than that!

 

[Herb-alaska]

YIKES!!:shocked2: Something wrong here! I am in the Seattle area and I usually get between 25 and 35 fills per cartridge (the book says about 40 but...).

Make sure your priority valve is working. If it is OK, then you may want to do blowdowns a lot more often. You should be getting a heck of a lot more fills than that!

Thanks ill take another look at it. I log every tank and service but did not check the log before typing but I remembered being told that I would get about 10 hours per filter which is a little more than ten tanks. But I really am not found of the litmus paper test that say change the filter. I may be changing to often all my pumping I'd outside and ak has a lot of moister in the air but so does Washington. So I need to check on this. It would definitely drive my over allcost down to extend the filter time

 

[rcontrera]

Ah ... I see the problem ... MATH!

With your big 130 tanks it should take you about 30 minutes to fill. Based on their 10 hour rating (never seen that before), you should be getting about 20 fills per cartridge.

The cartridges are rated for 3000 cubic feet of air at 70 degrees. Since the average 80 only gets about 70 cubic feet of air pumped into them that's around 40 fills. With your big tanks, ideally you should get as many as 27.

In real life, that 20 number is more realistic.