Mrodair Airmax Compressor Review: Prep, Poor Build Quality, Fixes, Ultimately Unsafe for Use
For those working on their MrodAir Airmax Extreme compressor, this thread is both a resource and report of my own experience. Work on my compressor evolved over time. Initially, the focus was preparing the compressor for a longer life, easier maintenance scheduling, and safer operation. As issues were discovered, this devolved into troubleshooting, fixes, and currently finding my compressor unsafe to use until an oil-in-air problem fix is found at Mrodair.
You can follow my journey beginning in October last year http://www.talonairgun.com/forum/viewtopic.php?f=52&t=33430
This thread is that Guinea Pig thread’s more useful successor.
The first few posts in this thread cover major topics. The major topic posts continually undergo editing to keep information up to date. They do not attempt to preserve chronology. Posts after the major topics are chronologic, just as in any normal thread.
NB. Changes in the major topic posts are not flagged as new by the BBS system.
===========================
Disclaimer: Material presented here may be incomplete or inaccurate.
Work you undertake on a compressor is expressly at your own risk.
===========================
Introduction
I pre-ordered my Airmax compressor from MrodAir after watching their product introduction video and reading the website. My impression was that the compressor would be a mid-priced, mid-performance machine suitable for my limited, single shooter needs. The promise that a US outfit would be going over the units and making sure they worked was reassuring. With its advertised “silicon bronze rings”, “3 cylinders”, and real pistons, this seemed a happy medium between an o-ring based compressor and the “overkill” of a dive compressor.
We were reassured by MrodAir that each unit would be tested and that they had arranged many upgrades. These compressors would be long lasting, “real deal” compressors. As an airgun newbie, I was unfamiliar with MrodAir. There were some negative online reviews, but I also know that online reviews often trend towards the negative – even unfairly. I took a chance, ordered a compressor, and promised to report my experience on this forum.
My desire was a compressor that would let me fill or top up a tank reliably. I was only a single shooter, but the convenience of ready air was enticing. Also, the ability to use high air consuming items, like regulator testers, made a compressor/tank combo a nice step up from hand pumping.
My experience has not been consistent with a ready to go, fully developed product. Others have fared both better and worse than I. There are issues potential buyers should know before purchase.
False Advertising
There were factual inaccuracies in the product advertising at MrodAir. These incorrect details affected my decision to place an order. Had they been accurate, I might not have placed an order.
As described on the product page when I ordered the machine…
No, this is a TWO stage compressor. Only two cylinders do actual compression. Although the 2nd stage piston rides atop a carrier piston, that carrier piston does zero compression work. It is drilled through and lacks air inlet or outlet. It is simply not a compression cylinder. The compressor can still achieve 4500 psi by making the two stages work harder, but the 3 cylinder count is a factual error. I am only counting cylinders that perform compression. Otherwise, one could lash a six-pack of beer to the compressor and dub it a 9 cylinder compressor. Two cylinders means each must do more work than in a three stage machine. There is also less chance for interstage cooling of the compressed air.
Silicon bronze piston rings were prominently mentioned as a feature of the compressor. This gave the impression that rebuild intervals would be consistent with that of metal piston rings. I was surprised to find my 2nd stage piston rings were not metallic. The rings resisting the greatest heat and pressure, are polymer
Several other owners confirmed that the high pressure cylinder rings. I informed MrodAir and the initial reaction was that I was wrong. Their website continued to advertise these compressors as having silicon bronze rings for several days more.
Piston ring description was adjusted as of 4/22/2016. The high pressure rings are now described as silicon bronze suspended in phenolic resin and the low pressure rings as traditional cast iron. The number of cylinders advertised remains three.
Because the 2nd stage rings are now known to be a less durable material than silicon bronze, having replacements is even more important. The high pressure rings look like angle cut wear rings. They are soft and easily indent with a fingernail. Heat, flame and smell testing of one from my compressor makes me think these are actually silicon bronze filled PTFE wear rings. I would like to find a second source. I have yet to find a source for bronze filled phenolic resin rings, but silicon bronze filled PTFE wear rings do exist.
Durability and duty cycle should be scaled back in your mind. Filling a 88 cf tank in one session stresses the compressor to its limit. A reasonable expectation would be to top off a tank once in a while or fill a gun directly. Long term torture testing suggests 20 minute max run times. http://www.gatewaytoairguns.org/GTA/index.php?topic=107945.0
Technically, the compressors are 120 volt units, but they need a 30 amp service outlet to run properly. A 20 amp circuit is insufficient. My own unit draws about 24-27 amps during operation. It is simply too large a current draw to safely run on a 20 amp circuit. Perhaps one could get away with it for filling a gun directly, but topping or filling a tank is asking a lot of a 20 amp circuit.
Electrical Hazard
My unit arrived with two major electrical components (relay and contactor) hanging loose. Each was held in place only by the wires connected to them. A consumer who receives the machine reasonably expects safe and secure wiring. If your unit arrives in the state mine did, disaster will happen in short order.
The compressor is not grounded. Grounding pin of its AC power socket is connected to ….. nothing. This machine has a semi-open, metal frame, uses water for cooling, and is not grounded.
An under capacity 15 amp IEC receptacle connects the AC power cord to the compressor. The IEC connector is only 15 amp rated, well below the actual current draw of the compressor. The IEC power connector can overheat or starve the machine of adequate power.
Electrical wring skills can correct these shortcomings. It is doable, but for a vetted design and build, the average buyer should not need to do electrical rework.
Air Quality with Heavy Oil Contamination, (Critical Go/No Go Safety Item)
My unit, and that of some other owners, continually passes oil from the crankcase into the low pressure cylinder. Oil that gets into the air path oxidizes (maybe even diesels) at the high pressure cylinder, fouling that cylinder’s rings and valves. The remaining oil goes on to the water separator and MUST be filtered out before it reaches a gun or tank. A little oil is not uncommon for a compressor, but it must be removed with a filter before it gets into your tank or gun. My unit splatters oil all about in the low pressure cylinder. Bleeding the separator filled my garage with suspended oil vapor. Not all units have this problem. Mine does and so do some other owner’s. This is distinct from being shipped with oil in the crankcase. It’s actively putting more oil into the cylinder with each stroke.
This oiling issue should be tested before one puts the compressor into use. An affected compressor will still fill a tank. Merely testing whether the compressor will fill a tank is insufficient. You should disconnect the air output of the 1st stage and specifically check for continued oil output before you try a pressurized run. Without my large, Alpha filter, this would have been an oil in the tank disaster. With my Alpha, it is still a problem. A filter can only handle do so much. Filters are meant to deal with the the last traces of oil, not heavy contamination. Oil in your high pressure air system is an explosion hazard and may negatively affect seals in your guns.
Summary
There are indeed MrodAir upgrades like the automatic cutoff gauge and radiator. Those are useful, but one needs to go over these units carefully before use. Expect to do electrical and mechanical work to keep them running. Mine, as delivered, was neither turnkey nor ready to use. Ultimately, mine had such severe oil contamination issues that it was unusable and no fix was forthcoming from Mrodair. On the up side, the compressor is easy to tear down and work upon. If good parts were available, and fixes developed, one could conceivably keep a unit running until one could afford a more robust solution. Just anticipate needing your mechanical and electrical skills.
The compressor does fill fast – perhaps too fast for its own good, Takes about 80-90 minutes to fill a Great White from empty to 4500 that’s with frequent bleeding. It’s just a tad over 1 CFM. You can actually see the pressure gauge of a Great White move as the compressor works. However, there are reliability, longevity, duty cycle, and oil contamination issues that need working through. I never got mine sorted after months of patient work.
My story follows. You will learn about initial inspection, electrical, air leaks, oil in air contamination, and blowouts. There is even a down trodden me “throwing in the towel” and ready to scrap the machine after first discovering heavy oil contamination and suffering another o-ring blowout while filling a tank.
I think one might get this compressor to marginally work directly filling a gun or a small cylinder, but expect very slow to no customer support if you encounter real issues. This is a machine built to the barest margins possible to still run. It has no pressure safety releases and should not be run more than 15 – 20 minutes at a time. You need electrical and mechanical skills to keep things in good order. This is of course, if you get a good unit in the first place. Test thoroughly when it arrives. You are the factory’s last quality control step.
Guy
Main Topic Posts Index
30 amp 120 volt RV service outlet Installation.
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357139
Delivered Components
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357140
Initial Inspection
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357141
inspection of cylinders for oil seepage during shipment
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357142
Opening Crank Case for Complete Oil Change (No, not for routine changes!)
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357143
Electrical Fixes and Upgrades
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357145
High Pressure Valve and Water Separator
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357146
Automatic Pressure Switch Gauge Glycerin
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357147
Water Cooling System
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635#p357148
Piston and Piston Ring Measurements
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635&start=60#p359151
O-ring Sizes
http://www.talonairgun.com/forum/viewtopic.php?f=52&t=34635&start=40#p358769
Latest changes
5/21/2016
No Mrodair fix for the oil in air contamination issues. Lower pressure cylinder consumes oil severely. Small engine shop evaluation suggested piston and cylinder tolerance are too large to ever effect a seal. Without a way to fix that problem, the compressor is unsafe to use. My unit is now going to another victim/owner for use as a parts donor.
If you are contemplating this compressor… my painfully earned advice is to buy from a different dealer and get a Shoebox or save up for a full scale dive compressor. The Mrodair Airmax Extreme compressor is a poor quality product you will most likely regret.
All Replies
All oil lubricated compressors will put some oil into the air stream. Even the full scale dive compressors. The difference is in quantity and whether the filter system is adequate to remove the oil AND not be overwhelmed. The output air should be nearly free of all oil. Otherwise, it’s flammable material in a pressurized (high oxygen available) environment. If that doesn’t scare you, also think about what that oil is doing to your seals in the guns even if you don’t have a catastrophe. The goal really should be practically no water nor oil in our high pressure tanks and guns.
Having experienced both ends of the scale in terms of oil amount being put into the air, I can tell you all there really can be a huge difference. My particular Airmax was a truly awful unit. Not all are like mine, but if you have one like mine was, stop using it. Mine was so bad, that it filled my garage with enough oil vapor (vented during bleeding) over a 20-30 minute period to make the air like a fog bank. That’s LOTS of oil. Doesn’t sound like TBear’s or MikeSatx’s current unit is anywhere near that volume of oil consumption. My Bauer doesn’t put out any appreciable oil vapor during venting.
I was saved from my Airmax only by virtue of the Alpha filter having an activated carbon segment that absorbed the oil getting through the compressor & its separator. Remember, neither silica beads nor molecular sieve remove oil. If anything, oil makes silica beads less capable of absorbing moisture. Molecular sieve is more resistant to oil ruining its water absorption capability. I was truly worried that even the Alpha had not removed everything and was contemplating the need to take my tank apart and washing it out with solvent to remove oil that had gotten into the tank. That would have also necessitated completely removing all traces of solvent. Thankfully, when I vented my tank, there was zero odor of oil nor any water. The Alpha had amazingly done its job for 80 minutes. Much of the oil was removed by the water separator, but the strong odor of oil on the intake end the alpha filter cartridge told me it had taken a hit. I don’t know how much longer it would have lasted against the onslaught my Airmax was putting out. At the heavy oil rate my unit was consuming, it would have run out of activated carbon capacity and oil would eventually get through. Add to that the heavy oil fog I was breathing in my garage and clearly it wasn’t safe to use.
A unit that is putting out far less oil, would not fill the room air with oil fog. Also, it would be within the range that the filter cartridge in an Alpha could be expected to last a several tanks worth of filling. That’s only if the unit puts out limited oil. Hence, you have to check the unit for oil output and so you can plan your filtering changes appropriately. The oil consumption issue is NOT worsened by running longer. Going more than 20 minutes wasn’t an issue re the oil consumption. That happens immediately upon startup if you have a problem unit. The 20 minute recommendation is to avoid heat buildup and subsequent high pressure ring, gasket, and o-ring blowouts. So, no, limiting a unit to 20 minute runs won’t save you if you have one that has an oil problem like mine did.
I keep mentioning the $$$$ Alpha filter, because it HAS an activated carbon segment and a pressure maintaining valve. The former lets it remove residual oil. The latter improves water removal by your separator. The activated carbon only works if the air it sees is already dry. That is the last thing the air goes through during processing. It is a high cost filter unit, but it DID the two jobs well despite absolutely horrendous conditions connected to my Airmax oil vapor production machine. It also really does keep the chemicals separated from the pressure vessel wall. I have no idea how much a replacement cartridge will run for the Alpha.
I haven’t ready anywhere that a Diablo can be effectively packed with activated carbon after the chemical sieve. Maybe with a felt pad between it could be possible, but I haven’t read of any reports of someone doing so. All I know is the Alpha saved me and my equipment. I think it is overpriced relative to the Airmax compressor, but feeding our tanks and guns bad quality air is stupid economy.
So, yeah. Keep those run times short so you don’t blow out the compressor. Check for oil consumption so you won’t inject too much oil to be removed. Finally, arrange an adequate filter that removes water AND once the air is dried adsorbs what residual oil is present. The dive compressors have a much better water and oil separators than the Airmax AND include drying and oil absorption filters. That along with more robust construction and multiple safety reliefs make them more expensive, but I think ultimately safer for us and loved ones around us. We’re messing with a long to pressure and stored energy. While it would be nice to save to some bucks, as I foolishly though was possible, I’m so glad to have that machine out of my hands.
My advice is to hand pump a bit longer and save up. By the time you add an Alpha filter to the Airmax you’re almost half way to a dive compressor. You are also all the way to a shoebox & an Alpha.
This has convinced me to invest in the Diablo Air Dryer high pressure filter. It’s probably the best thing us 50 airmax compressor owners can do to avoid catastrophe.
Btw, last night I couldn’t sleep and spent 2 hours dismantling and cleaning the compressor. Low side has little oil, as well as high side. But high side were very fouled and disgusting. Brown stuff everywhere. I opened the moisture filter and clean out and replaced beads. Disgusting in there too. Trace of oil there.
I will test compressor next week and see if oil is found in system, regardless I’m leaning toward the Diablo filter because fear has been mongered.
This is how I see it, once you make a good low side gasket (high temp rtv – let cure then tighten) that is best we can do. the pump will send some oil and water thru the system. that is fine IF it doesn’t get into the tanks and gun AND you don’t let it build up in the filter. you don’t have to take the low and high sides apart again until you replace high side rings.
You will get to know how bad your compressor is bypassing oil very fast and time your cleaning accordingly.
If all you can afford is the Diablo then great but I truly think the Alpha is worth every penny,remember even after your compressor is long gone you can use the filter anyplace you fill your guns and tanks. think long term for the filter.
as for your guns and tanks, I would drain remove valves and clean them out with an oil cutter like dawn dish liquid, wash and let dry then rebuild.
Well that certainly is scary. But what am I and at least 49 others to do with our scba tanks or airguns that was already contaminated with oil from the air max compressors? Must we empty (very very slowly) our tanks and remove said oils? And how exactly can we do that and be sure that no traces of oils are left behind, because even an infinitesimal amount of oil will cause a big explosion.
This has convinced me to invest in the Diablo Air Dryer high pressure filter. It’s probably the best thing us 50 airmax compressor owners can do to avoid catastrophe.
Btw, last night I couldn’t sleep and spent 2 hours dismantling and cleaning the compressor. Low side has little oil, as well as high side. But high side were very fouled and disgusting. Brown stuff everywhere. I opened the moisture filter and clean out and replaced beads. Disgusting in there too. Trace of oil there.
I will test compressor next week and see if oil is found in system, regardless I’m leaning toward the Diablo filter because fear has been mongered.
http://www.pbnation.com/showthread.php?t=2325446
http://www.warpig.com/paintball/articles/news/090602HPAwarn.shtml
If you believe that your tank will explode, everybody who purchased the air max compressor better throw your tanks away! Since your tank is already contaminated when they tested the compressor before shipping to you. It’s a ticking time BOMB!
I don’t know how you’re going to safely remove all the oils in your tank. The moment you open the valve your tank will EXPLODE because it’s a BOMB!
One? How about 2? Not the actual gun, or tank, but the weakest link in the chain……and this was just with the heat created from the speed of hand pumping. Petrol based lube (oil) in a high pressure pump is a NO NO
http://www.gatewaytoairguns.org/GTA/index.php?topic=13977.0
http://www.airgunnation.com/topic/do-not-use-superlube-grease-for-pcp-handpump/
Mrodair compressor will work fine if you follow these important rules.
1. Don’t attempt to fill scba tank from empty to full. That’s where these people make mistake and then blaming mrodAir. Heat is the killer. Don’t use compressor more than 20 minutes at a time and make sure it’s well cooled with at least 5 gallon water. It was never meant for filling empty tanks. It’s for topping off or filling gun directly.
Right from the MRodair website “advertising the compressor
Filling tanks from 13ci to our largest 4500psi SCBA, we have found none faster in any compressor at even twice the price.
What filter are you talking about?
You didn’t get filter material in the water separator? I sure hope you check.
I filled my tiger shark yesterday it took 16 min 3k to 4.5k. at 10 min I took apart and replaced the filters, the desiccant was pink and the paper filter was starting to get dirty. I don’t need to do this anymore since I have a alpha filter on now but why waste the alpha’s filter if I don’t have to.
You are acting the fool for reading all these posts and thinking you don’t have to clean and replace filter inserts.
warranty ? I can’t even buy replacement filters its been weeks and he will not even answer my emails, you would think its easy money selling the cheap filters these come stock with.
One? How about 2? Not the actual gun, or tank, but the weakest link in the chain……and this was just with the heat created from the speed of hand pumping. Petrol based lube (oil) in a high pressure pump is a NO NO
http://www.gatewaytoairguns.org/GTA/index.php?topic=13977.0
http://www.airgunnation.com/topic/do-not-use-superlube-grease-for-pcp-handpump/
Mrodair compressor will work fine if you follow these important rules.
1. Don’t attempt to fill scba tank from empty to full. That’s where these people make mistake and then blaming mrodAir. Heat is the killer. Don’t use compressor more than 20 minutes at a time and make sure it’s well cooled with at least 5 gallon water. It was never meant for filling empty tanks. It’s for topping off or filling gun directly.
Right from the MRodair website “advertising the compressor
Filling tanks from 13ci to our largest 4500psi SCBA, we have found none faster in any compressor at even twice the price.
What filter are you talking about?
You didn’t get filter material in the water separator? I sure hope you check.
I paid exactly $975.
I bought mine strictly to top off my Airhog 88cf tank from 3000psi. Who do you know that use all their air all the way to 0? All you have to do is fill from empty once. Just do that in 20 minutes intervals and you’re good to go.
If mrodair did fill up two empty tanks, I reckon that’s why we have many compressors have problems. Just don’t do that again!
So you paid $1000+ for a compressor thst can’t fill the tanks we use.
He says he fills 2 tanks from 0-4500 before every compressor shipped.
What’s the point of having this compressor. Even a shoebox can fill a 88 cf tank.
The compressor is a flop.
Quit with the fear mongering. Show me one instance of air gun or air tank blowing up because there was oil in the tank.
Mrodair compressor will work fine if you follow these important rules.
1. Don’t attempt to fill scba tank from empty to full. That’s where these people make mistake and then blaming mrodAir. Heat is the killer. Don’t use compressor more than 20 minutes at a time and make sure it’s well cooled with at least 5 gallon water. It was never meant for filling empty tanks. It’s for topping off or filling gun directly.
What filter are you talking about?
I refused to take apart the compressor to check for oil. If it’s working I’ll not going to take it apart risking messing anything up and voiding the warranty.
Wow – I mean what can you say? You almost got a full hour on it and it hasn’t quit yet? Great. Not sure what to make of the fear of checking to see that it might be leaking oil. I guess if you hit the switch and it pumps all good. Have you checked the “filter”?
I would just make sure that each time you start pumping up that gun (that might be filling with oil) you keep everyone else far enough away to avoid any blasts.
If you get this machine, test it out right away for the oil issue. That is one problem you can’t work around safely. If you are lucky to get one that doesn’t consume oil, treat it gently and limit run times. It’s not a robust machine.
Hi Guy yeah I got lucky I wasn’t sure what was going to happen when I sent it back. Didn’t send any request for money back or anything. A week later another compressor showed up. That’s when I noticed it had fluid in the pressure gauge,the first one was empty when it showed up.
I stopped using the water tank that came with the first one. Went to using a five gallon bucket with a heavier duty pump. The temp dropped 10c. 90ci last me a week worth of shooting.
You don’t care if you get a little oil and water in your tanks and guns?
You actually think your compressor has a warranty :rofl: :rofl: :rofl:
I only filled my 88cf tank from 3000 to 4500 psi once. Filled my cricket from 120 to 300 bar. Filled my 22ci tank from empty to 3000 psi. So I got less than an hour on it. I haven’t check for oil or water, nor would I. I’m not breathing the air and I don’t think a little oil or water would do any serious damage.
I refused to take apart the compressor to check for oil. If it’s working I’ll not going to take it apart risking messing anything up and voiding the warranty.
- You must be logged in to reply to this topic.
I think there is an apology and a Thank You somewhere in the below post.
This has convinced me to invest in the Diablo Air Dryer high pressure filter. It’s probably the best thing us 50 airmax compressor owners can do to avoid catastrophe.
Btw, last night I couldn’t sleep and spent 2 hours dismantling and cleaning the compressor. Low side has little oil, as well as high side. But high side were very fouled and disgusting. Brown stuff everywhere. I opened the moisture filter and clean out and replaced beads. Disgusting in there too. Trace of oil there.
I will test compressor next week and see if oil is found in system, regardless I’m leaning toward the Diablo filter because fear has been mongered.
What do the 50 compressor owners do? You yell and complain at MRodair until he provides you with a safe and reliable compressor or a return of your money….