Do you leave your compressor pressurized?

[bing!]

I drained mine today and will do so everyday. Like you guys say, it's a small tank anyway. Thanks again! /bing

[chopnhack]

After I am done with mine I drain it. I don't like the idea of leaving that much moisture inside for too long.

[Relative]

The inside of the tank is not treated to prevent corrosion and I guarantee you that you do NOT want to be around should your tank ever rupture.
CWS

Therein seems to be the key. Just how do you make some sort of effort to treat the inside of the tank to prevent corrosion? Is it even possible to access it somehow and create a fog of something like Rustoleum to coat the inside and at least slow down the process?

Ideas?

Mike

[PhilofKayDu]

Therein seems to be the key. Just how do you make some sort of effort to treat the inside of the tank to prevent corrosion? Is it even possible to access it somehow and create a fog of something like Rustoleum to coat the inside and at least slow down the process?

Ideas?

Mike

I have wondered about this same topic. Would someone please explain? And how long does the average portable air compressor last? Phil

[Cochese]

Nice topic. I was considering picking up the HF 2HP 8gal hot dog compressor this weekend. As I have no permanent power, I'll most likely be draining every time I use it.

[cabinetman]

The short answer is that I've had/have compressor tanks that never failed. One is still working fine after 35 years.

Under ideal humid conditions compressor tanks, and airlines can become moisture collectors and transmitters. The principle is simple. Humidity is a level of moisture in the air. When a compressor is running, it takes in the air to compress it into the tank.

In addition to that, in the compression of the air the air gets heated, which in turn will develop moisture. Some of that moist air will collect on the walls of the tank and some will stay in suspension for a short period and collect at the lowest point, which will be the bottom of the tank.

Draining and drying out the tank is only effective until the next time the tank is filled, moisture will gather. The problem is to remove or control how much of that moisture gets passed out to the airline, and eventually to the air tool.

The moist air in suspension can exit the tank when an air hose is used. Now, we have a new source of collection...the air hose. Besides the hose carrying the moist compressed air, the movement of that air through the hose will develop its own source of warmth just by the friction of the movement and create moisture. What moisture doesn't get transferred to the hose will collect in the tank.

So, now you can see that there is a never ending source of moisture being utilized and created. How can moisture be controlled? There are a few remedies. An air dryer can be used which cools the air, and the water can be extracted, so you wind up with cool dry air. Dryers can be very expensive and usually wouldn't be part of a homeowners set-up. Very few professional shops on a small scale don't budget for driers.

An alternative method is to create a path for the air which allows for the collection and extraction of the water with a run of airline long enough to provide some cooling. For small shop conditions just installing a filter at the tank that handles the airline can be very ineffective. The fact that it's close to the air pressure, hot moist air can get blown past the filter. The air is warm at that location, and gets moved on along the air line.

The fix is to come off the tank with an airline, and have it placed at an incline, with a drain tap along the way. At the end of the airline, mount a filter and a regulator. It also will have its own drain tap. Then from there, have your working line to the air tool, whether it being a spray gun, fastener, sander, drill, etc. To maximize collecting the air, install on the tool, a disposable filter (could also install a small regulator). There are shapes to those filters that can be convenient to the tool. Some are bulb shaped, some are tube shaped, and they thread right on the tool, just like a QD fitting.

If you don't have the room for an elaborate layout system, fitting up a small compressor with an effective use of space can be helpful. This thread discusses how to configure a small space for a compressor, and a drawing which explains how to layout airlines with drain taps.
.

[PhilofKayDu]

Cochese, When I had to replase my air comp., I went for the HF 3HP 10 gl. I love those sells and coupons. C'man, thanks for the info. I don't think Shopnotes or Wood mags. ever explained it any better. Phil

[eezlock]

do you leave your compressor pressurized?

Yes, I have an 80 gallon horizontal tank with a cast iron pump (twin cylinder).
It stays on line all the time, basically, in severe cold weather I may and do sometimes turn it off, if I'm not going to use it for a few days. This is an old
60 year old service station compressor that is outside under a slant roof
exposed to the weather and never gives any trouble. I had to replace the electric motor a few years back...but no big deal, this thing runs very quietly
for a large old compressor. We could stand right beside it while running and it won't make enough noise to interrupt our conversation. I usually drain the condensation from the tank about once a week...never much to worry with
maybe a half a cup of water and that is it!

[Norm in Fujino]

I drain mine after using for the day. The petcock stays open until I'm ready to use it again.

FWIW, my neighbor, whose opinion I have a great respect for, doesn't drain his. But I think leaving the tank with water in it, invites problems.

Ed

I agree, especially here in Japan's humid clime. I neglected to depressurize mine for one day and the next time a lot of rusty water came out. I leave my valve open when not in use.