How much rust is to be expected in an air compressor tank?

[Vywr]

I recently got my first air compressor, it was a used 6-gallon pancake Hitachi, made in 2017. After fixing some leaky valves and stuff, it works well. However, when I drained it for the first time, the water was very dark with rust and particulate. After doing some reading online, apparently some rust is normal for these. Anyway, I decided to try to rinse out the particulate and give it a treatment with a rust chelation solution since it was interfering with the drain valve's seal.

There were some big chunks of rust!


I was pretty concerned, so I got a cheapo endoscope to take a look (good photos are very hard to get with this method):


While the tiny endoscope definitely makes things appear bigger than they actually are, this seems like a pretty worrying amount of corrosion to me. At this point, I'm thinking about drilling some holes in the tank to decommission it and scrapping the thing. But then again, I don't have much experience with air compressors, so I don't really know what a "normal" amount of corrosion is supposed to be. Am I just being an compressor-hypochondriac?

I've seen that people can get these tested for pitting or pressure holding ability, but it's obviously not really worth it on such a small tank. If anyone has ideas about what to do with the remaining parts (the pump and motor still work well), I'm all ears.

 

[Shoreline_]

I wouldnt worry about it. Itll pin hole before it ever explodes. Many years from now. Just drain it regularly.

Other factors include your ambient weather conditions. It being so cold, many places aren't seeing much water in tanks. In the summer it's a different story.

 

[cgrutt]

Probably normal (typical) but you can pressure test it yourself pretty easily if it makes you feel better. Various methods with water (via hand pump, grease gun or pressure washer) can be found on internet. You want to test at 1.5x rated capacity (so if tank is rated for 100 psi you should test at 150 psi) with water. Water removes risk of tank exploding (catastrophic failure) if it fails. You can buy a cheap hand pump such as this (there are many alternatives this one is pretty inexpensive) to test it. Good luck.

 

[Vywr]

Thanks for the advice guys. I'll probably continue using it for the time being; eventually I plan to upgrade in any case.