I would like to share our experience with the MikroTik NetMetal ax.
We were hired to deploy multiple point-to-point links ranging from 1 km up to 28 km. We successfully achieved these links using the MikroTik NetMetal ax together with the MikroTik mANT30, performing precise alignment. The performance has been excellent giving the distances, as shown in the photos below.
However, after approximately 9 months of operation, we started facing serious issues with corrosion in several units. Some radios are going offline, and upon inspection, we observe visible corrosion on the exterior (for example, on the grounding screw) as well as internal corrosion inside the device.
We are unsure how moisture could have entered the units, as we followed the recommended installation procedure. We used the original rubber sealing ring and made only a small cut to allow the surge protector cable to pass through.
According to official MikroTik support, the devices going offline could be caused by “bad assembly at the installation site.” However, we are struggling to understand how equipment rated with IP66 protection could reach this condition after only 9 months of operation, especially with corrosion visible even on the external screws and near the led indicator.
Because the issue has been classified as improper installation, the units are not covered under warranty. This has resulted in significant replacement costs for us and is making us reconsider whether we should use a different brand for similar installations in the future.
Has anyone else experienced similar corrosion issues with NetMetal ax devices in outdoor deployments? Also, if someone sees something strange in the installation photos above, let me know! We are always learning
Thanks!
PS: The fotos of the damage device are actually photos of two different devices, one that we had opened, and another that we didn’t touch but externally we can see exactly the same problem
We live in a desert climate, so I don’t see much in the way of rust and salt corrosion on our gear. But when I see the green stuff on my equipment, it’s typically because water got in where electricity is flowing. For us that’s usually on the RJ45 ends and inside POE ports or adapters.
Did you have cables plugged into the SFP cages? Were the radios grounded? Corrosion on those things could indicate current flowing to the grounds, which means something is wrong electrically.
Rust on the screws means poor choice of metal on the part of the manufacturer.
I can see several different issues.
The bubbles in the paint near the leds (top left photo of the 6 set) seems like a defect of the paint (or of the surface below it).
The rusted screws/pins (right top and right bottom of the set of six) are (IMHO) "normal" rust, you can avoid it in most cases putting a little bit of vaseline grease on top of them at installation time.
Both the above should be mostly esthetic issues only.
In the top right picture it seems to me like you also have a broken screw (probably removing the unit from the pole), there as well filling the threaded hole on the aluminum case with a bit of vaseline or silicone grease would be a good idea.
The real issue is condensation/water/humidity inside the device.
From the first picture the cables going to the antennas seem mounted correctly (but cannot say if you used (not a bad idea) some self-fusing tape around the antenna connectors.
The way the bottom cable is isolated when entering the bottom cover is not detailed in the photos, from the first photo the downfacing loop is a little too tight for my tastes, but it is unlikely to have brought water inside the device.
So, what remains is condensation.
Not related to Mikrotik devices, but my experience with other similar outdoor devices is that there are only two possibilities:
the device is completely watertight (submersible up to 1-3 m depth in water and sealed in a temperature and humidity controlled environment) that would be IP67/68 (or 69)
the device is IP66 or lower, that mean that water can - in some cases - enter it.
If the device - like the netmetal Ax - is IP66, water can enter it, so it is a good idea to give it the means to have it exit the device, via a hole in the lowest part, possibly with a vent/breather valve.
Only for the record, and unrelated to this specific device, the good Mikrotik guys are now putting a vent/breather valve on the Cube Pro's (that have a bad reputation for sealing), see:
Now they don't make them as high-quality as they once were...
This one was replaced a few months ago with a product that supports the 4096QAM.
It had been in service since 2014, and the sea, where it was mounted, was only 4 km away...
This is caused by one thing! Down cost production price caused by lower quality elements and materials. Im agreed that older models was made a much much quality then current ones.. Mikrotik and Ubiquity too make the same thing when assembly and product current products. They rely on their "status" in the past, and sell inferior products with much lower quality control, and also cheaper materials that shows their "gratitude" for short time after installation! Correct me if im wrong.
I also opened this device to modify it so that it had two radio modules inside
(in fact there is the additional label and the additional 2 outputs in "aux"),
and inside it's perfectly made...
I would look at that surge protector, looks like part with the 2 wires going into it is pointed up. Water could run down the grounding cable, into the surge protector and then drain down inside the CAT cable into the radio. We have seen things like that happen before.
I see that same sort of bubbling when corrosion gets under aluminium.
As for the Vaseline I would go for a silicone grease, then you can put it on the rubber o-ring and they shouldn’t get eaten by it and the seal on them will be a heap better than without any grease
For the corrosion bubbles around the leds, there is no mechanical defect visible. So it must be a fault at factory. And there are several possible reasons for this to happen. In any case I would classify this as a manufacturing defect.
The corrosion on the grounding screw could be galvanic corrosion. The surge protector might also not be completely sealed, exposed perfectly to rain, especially against humidity or condensation. Moisture could travel along the network cable and enter the housing this way.
