Steel tank expiration dates

[Nessus]

Steel accessory tanks come with expiry dates stamped on them, mostly due to condensation-related corrosion concerns, as I understand it, and aluminum tanks do not, since aluminum doesn't rust.

However, I've noticed compressors with built in steel tanks don't seem to have expiry dates. At least, not ones as well advertised as with accessory tanks. I can think of no reason why compressor tanks would actually be different than accessory tanks in this regard though.

So... do steel tank compressors have expiration dates too? If not, is it prudent to assume they should anyway, and replace the compressor (or just the tank) after a few years? Are replacement tanks even available (if they were, you'd think the DIY fridge compressor guys would use these instead of "old" tanks from second-hand broken compressors), or would you be looking at replacing the whole unit even if the motor was still good?

 

[MacRaven]

Hi, i don´t know how this is handled elsewhere in the world but,
here in Germany every real tank has an expiration or technical review date. If you buy from cheapo china they don´t have usually.
But that means just they don´t need that review in china.
You are completely right with your guess that is because of possible corrosion inside the tank.
Here it is handled that way that if it an official work tank for a company you have to check it regularly if not and something happens and you can´t
provide the checking protocols , then you are in serious trouble.
Same is valid for personal use, but no one will ever check it, if nothing happens all is fine.
But you still don´t want an accident with a not checked item/tank.
If you but a quality tank from a serious company then the tanks have a chance of having some kind of coating inside.
That coating protects the tanks inner walls. But this coating still does not last for ever.
If you have the chance to have a regular visual inspection of your tank it should be fine to simply act as soon as you see first rust spots.
As far as i know it is possible to get a new tank from every manufacturer. E.g. i just exchanged my cheapo china AS-18 3litre tank.
I am something that is equal to a technician in the rest of the world, here in Germany it is called "Master" but is NOT an University title.
I would really advise you that you should have a look into your tank lets say once/twice a year depending on usage. Just take a torchlight and peek into one of the holes, best would be when you are able to see the tanks bottom.
But to be honest lets assume you have bad corrosion inside the tank. As long as you don´t store it away under full pressure it will be no big deal because
as soon as you start filling a rusty tank you will just get some heavy leakage and thats it.
A complete break or explosion is quite uncommon with that low pressures, i assume you have a simple air tank with roughly 8 bar/116 psi.
But still it will create a nice mess inside a room.
So nothing you will want.

I hope that was helpful.

 

[RebelAir]

99/100 the compressors will give up the ghost a long time before the tank will but to be concerned about such is being prudent..It really does depend on each tank though individually as if I use a compressor in a humid part of the world I would have more concern about that kind of issue so its hard to regulate such, but you can also consider some basic tank maintenance that will assist, IE drain it regulary and occasionally flush it out with a rust treatment, will add a lot of years to the tank and remove most corrosion issue..but anyone worried about corrosion making a tank fail I point them to the titanic. 100 odd years in saltwater and still lots of steel left LOL..

 

[MacRaven]

@RebelAir i would be careful with your word about the dieing ratio of tanks and compressors.
As far as i see it most people here have a quality compressor here from a more or less good brand.
That means you are right in the case the compressor is not maintained and a throw away cheap part.
Otherwise if treated right, a compressor can last centuries.
For example in our company we have a 80 year old french compressor still running and compressing co2 up to 200 bar/2900 psi.

But the comparison with the Titanic is good, it just shows what i said already, the tank will most likely just leak and thats it. No explosion or anything dramatic.

 

[RebelAir]

i would be careful with your word about the dieing ratio of tanks and compressors.

In what way m8? was just saying the motor will likely give up the ghost a long, long time before a tank will, even if it has been going for 70 years but they don't build things like they used to :0

Myself I buy cheap, many around here do because its much cheaper to buy another $70 option 2 years down the track and not worry at all about corrosion, maintenance or any other issue, shiz I don't even bother filling em up with oil again anymore (It costs me half of what the compressors nearly worth for four liters and they still run for years (last one got me 7 odd years), even low on oil LOL (that one got filled once :0), its cheaper to buy a new one occasionly.

Was just saying in my post though that with basic maintenance/draining, they tank will outlast most of us no problem- the motor generally won't though, they don't really want them to, it always pays to respect compressed air but the worst corrosion normally does is turns every color red/brown LOL.

 

[Nessus]

Thanks for the advice. My current compressor is a "Husky" brand pancake tank compressor I got at Home Depot maybe ten years ago. I check the drain valve after emptying it each time, but nothing's ever drained out. I live in southern California, which while not super dry doesn't seem to have much humidity issues (pretty sure I could safely run my AB without a moisture trap, but I do anyway; though like the tank it always seems to be dry).

I use an accessory tank to get more brush time out of a session before I have to refill the air though, and it's just gone out of date. Like the compressor tank, it never seems to have any build up to drain (and I have another trap between the compressor and the accessory tank anyway), so I'm having a hard time determining how urgent I should be about replacing it. If the accessory tank should be replaced though, it seemed to me that the compressor's tank should be too, since it is older.

I've been thinking about trying a refrigerator compressor build, but all the instructions I've read say to scavenge a tank off a used/broken compressor, which seems risky to me if you don't know what the previous owners climate or maintenance habits were, or how old it is. So I was thinking of buying a new aluminum tank instead. One of the automotive ones with multiple ports: accessory tanks usually only have one port, and from what I gather a compressor tank needs at least 2. Those are expensive though, so one small aluminum tank + fridge compressor and fittings could come close to the cost of a CAT 1650A or 1610A, in which case I might as well buy one of those and accept slightly more noise as a trade off for convenience and safety. If using a scavenged second-hand compressor tank isn't as risky as it seems to my mind, then that would reduce the cost of such a project by a chunk, making it more favorable again.

 

[Bossman]

n/m

 

[RebelAir]

You could always consider not needing to trade of on noise or even worrying about it and build a silencing box for any compressor. jam a cheapie home depot style in there and hope it lasts for a few years, with the right insulation you can take 20 decibels of easy, if it blows just buy another and ram it in there..just take out the first one LOL..Really though when you look at cost comparison if you don't need portability a small 20-25 litre tanked compressor will cover all your air needs, suffer less condensation, no pulsation and a box probably built out of scavenged bits/insulation and pieces will cost under $50, a half decent silent compressor costs maybe close to 500-if not more and am sure even a modest aluminium tank will buy a few compressors LOL.. but if each one of mine lasts 3 years on average, I can buy 5 of them and get close to 15 years maybe out of them for the same price, if that one good one lasts 15 years then no real diff LOL

 

[Nessus]

I'm considering that too. The compressor I have right now is too bulky for it: building a box around it would make it take up too much additional space and make it too awkward to move. But buying one of those little tanked models and building a box around it, if done well, could be the size of a small PC tower and quite portable. In fact I have an old aluminum carrying case that would be perfect, just would need to add foam and a way to secure the compressor to the base, but that's easy to sort out. My only hold up is my lack of electronics knowledge for cooling fans. I have some leftover 80mm computer case fans I could use, but don't know what I'd need to put between them and an outlet to make them work properly/safely.

 

[AndreZA]

I'm considering that too. The compressor I have right now is too bulky for it: building a box around it would make it take up too much additional space and make it too awkward to move. But buying one of those little tanked models and building a box around it, if done well, could be the size of a small PC tower and quite portable. In fact I have an old aluminum carrying case that would be perfect, just would need to add foam and a way to secure the compressor to the base, but that's easy to sort out. My only hold up is my lack of electronics knowledge for cooling fans. I have some leftover 80mm computer case fans I could use, but don't know what I'd need to put between them and an outlet to make them work properly/safely.

Here is a dissembled one. https://sites.google.com/site/donsairbrushtips/badger-tc910-compressor-review

 

[Nessus]

Thanks!. It's cool to see the exploded diagram. That helps a lot in understanding when people talk about diagnosing or modding the guts of small compressors.

The page which is crosslinked in that article had a little nugget that helped a lot as well. I had been under the impression that the compressor and the air outlet should not share a port on the tank, but he was using a small oil-less compressor by attaching it to a single port tank with a T fitting. I have a wee tankless Badger compressor that's been buried in the garage for like ten years. I got it and abandoned it way, waaaaaayyyy back because it was loud, would walk around the bench even if I put a pad under it, and its factory-set auto shut off prevented it from being used at lower pressures. I could dig that out, and if it still works I can put it in an even smaller sound-dampening box and run a line out to a T fitting on my tank.

Still need to figure out the fan wiring. I'll bet computer fans get perverted for all manner of DIY projects though, so there's bound to be instructions out there somewhere. Just a matter of finding the right search terms.

 

[Mr.Micron]

Thanks!. It's cool to see the exploded diagram. That helps a lot in understanding when people talk about diagnosing or modding the guts of small compressors.

The page which is crosslinked in that article had a little nugget that helped a lot as well. I had been under the impression that the compressor and the air outlet should not share a port on the tank, but he was using a small oil-less compressor by attaching it to a single port tank with a T fitting. I have a wee tankless Badger compressor that's been buried in the garage for like ten years. I got it and abandoned it way, waaaaaayyyy back because it was loud, would walk around the bench even if I put a pad under it, and its factory-set auto shut off prevented it from being used at lower pressures. I could dig that out, and if it still works I can put it in an even smaller sound-dampening box and run a line out to a T fitting on my tank.

Still need to figure out the fan wiring. I'll bet computer fans get perverted for all manner of DIY projects though, so there's bound to be instructions out there somewhere. Just a matter of finding the right search terms.

you just need something like this http://www.censuspc.com/120mm-x-38m...-Bearing-AC-Cooling-Fan-w-3FT-Power-Plug.html
just install it and plus it in the wall or you can hook it in the on switch of the compressor .

 

[MacRaven]

@RebelAir sry m8 i didn´t want to sound that harsh. Its just that i think you are not considering that some people care about their stuff.
I mean even a cheap self made fridge compressor setup can run for centuries with just a very little service. So i just think that your argument is
only valid if you don´t care at all and use very cheap stuff.

@Nessus you can take either kind of tank, aluminium or steel if you are able to see the stuff before buying, just take a light and look into the tank
and you see whats up.

I just posted a simple silencing and cooling solution for this cheap single piston compressors. So maybe when you are able to put it into a case it might
be an option.

About the T-Piece In/out connection, hmm from the view of an technician i say it is not an elegant version and may lead to trouble but from
the principle it will work. Depending of the hose dimensions, the longer the better, because the pulsating Air from the compressor may interfere with the
settled air from the tank.
The hose will in that case work as some kind of additional tank volume to settle the air.

The fan question is just ac or dc. AC has the elegance that you should not need any more components to connect it to the compressor and you can
connect it in parallel with the compressor motor so it blows when the compressor is running but the backside of the medal its ac power, so
risk of electric shock, starting fires and so on when done completely wrong.

Second option is DC Power fans mostly for computer cpu coolers. (they are the most silent). Advantage is they are quiet, use the quite safe low voltage dc power, widely available and simple in connecting. But you need additional parts, the most simple version is taking some 12V wall wart connect + and - and let it blow. Or if you are out for a more technical solution you can build a power converter on your own to make the motor power usable for your fan that would let you have just one power plug not two.

 

[Nessus]

Thanks for the replies. The fans I have are 80mm computer fans, and use DC at 12V & 160mA. I did a google search for "wire a case fan for outlet", and holy sub-dermal hematoma, Batman, there's loads of stuff out there about wiring computer fans for creative misuse!

I want to use two in a push/pull config, so looks like I need a 12V wall wart in the 4oomA range. Like this one. I'm not nearly knowledgeable enough to wire a converter myself so they can be slaved to the compressor's auto shut-off switch, but I can easily put a wee outlet box inside the sound-deadening box so there'd be only one cord and master power switch on the outside. Besides, having the fans running even between compressor activations will just be all the better for cooling... though maybe it might increase stresses from heating cycles?

I was having similar thoughts re: using hoses to soak up the pulses. I was thinking of using something like this between the compressor and tank.

A check valve in the compressor -> tank line seems like maybe a good idea too.

 

[MacRaven]

Yes this is obvious the best solution for you. Wall Wart and good. Push pull config is very good. Remember to put some filter in front of the fan that fills you case, best would be on both. Otherwise you can and will pollute your motor maybe and this can be nasty, in case of temperature exchange and if it is an open motor/compressor case the bearings will last longer when clean.
Some fiber mesh for kitchen/cooking fans (sorry dont know how you call the thing over the cooking place) should do fine as dust filter to keep the case clean from inside.

 

[splasha]

If I may, I was having similar probs with pulsating compressed air.
To remove it, I made a small steel pipe tank and fitted it into the line between the compressor [ DIY fridge job] and the airbrush.
This has removed all the pulsing from my lines and has also allowed me to move said compressor away from my work area, hence less noise.
Seems to work just fine, for me.

 

[MacRaven]

Yes spalsha is right, to get rid of pulsating air the solution is to add as much Tank volume as possible. The new produced compressed air can settle and big volumes can prevent that the new air can disturb the old one that is already in the tank.
And with every tank added inline the air calms more and more.

 

[Nessus]

That's why I'd thought the compressor and brush shouldn't share a port: if they do, then whenever the compressor kicks on, you'd to some degree be back to getting pulses straight from the compressor instead of mitigated by the air having to pass through the tank. In such a setup, the air flow with the compressor active is compressor-->brush-->tank, instead of compressor-->tank-->brush.

So ideally I'd want a proper tank with multiple ports. I think I'll definitely get one, as it's something that can be re-purposed for multiple different setups/builds as I upgrade. However in the short term, a T-fitting with a coiled hose or a small pipe tank (an excellent idea, thanks!) between the compressor and the tank/brush seems prudent.

As I said, I already have a single-port tank to store pressure, so it's mostly a way of ensuring the brush doesn't suffer from pulses for however long I'm forced to rely on a T-fitting setup. If it works, the tank would end up being more to keep the compressor from having to run constantly, rather than to smooth the air while it's running, I guess. Once I get a multi-port tank, I can just plunk that in-line and be rid of the T-fitting and the need for a hose/pipe pulse mitigation stage.

Right now my main compressor (the shop-style one) is already located away from where I work. Running a pressure line through the walls is impractical where I am, and in any case the compressor is just too dang loud no matter where it would be (the garage is the least offensive place for it, but it's still loud enough to disturb neighbors and the like). Right now I'm working by charging up the accessory tank in the garage, then moving the tank to my work area. This gets me an hour or so of air, but when it runs out, I'm SOL 'till next afternoon or whenever I can run the compressor without disturbing anyone. Putting the little Badger (still works, yay, but needs cleaning) compressor in a soundproof case and sticking a T fitting on the tank would let me keep the tank permanently in my work room, and allow me to practice without being forced to stop when I've run out of air instead of when I feel finished.

Obviously buying or building a new setup from the ground up would be ideal, but if I can "get by" re-jiggering what I've got in a smarter way, that gives me a lot of room to breath on saving up for new hardware.

 

[MacRaven]

first off all i need to apologize for my manners and words i said here to RebelAir.

It was some misunderstanding and bad choice of words that led to a offensive words that were not intended to be offensive.
I hope i did not step on other feet. If i did please let me know think everything can be explained.
Again sorry RebelAir it was not meant that way.


back to topic:

hmm silencing one of this bigger compressors used for most kind of home/garden work is not that easy, as far as i know them they are really loud.
I don´t know any method that will bring it to a noise level that is suitable for indoor use.

 

[RebelAir]

All good m8 and appreciate your comment/reply, got to remember myself that with so many here English isn't everyone's native tongue and things sometimes come across differently..Especially when this Aussie is blabbering on LOL ...But on topic-

A silencing box is the only method to bring noise down..But it only really effects the noise in the hearing frequency's, a really good silencing box will also take into account the subsonic frequency's and vibrations with softmounts. If living in a small compartment you can build a box to bring a 70 decibel compressor down to 30-40 db which is acceptable conversation level noise and what the most high end silent compressors achieve (besides a fridge compressor).

I ran one of my 25 liter spears and jackson in a silencing box in my kitchen whilst my newborn slept in the next room not a problem for close to a year, as after I silenced the box and unit I also shoved it full of pillows LOL That thing barely whispered and was a shop style compressor and it out did most silent compressors I've owned sinced, probably shortend the compressors life a bit but never over heated or was an issue only died from rolling around the back of my mates ute but still kept going for a few months after that LOL, besides the moving of it but I had it on big rubber castors so that bit wasn't a huge drama to me as I didnt need it that portable and I also built the box to hold my airbrushes and inks as a toolbox..

It will cost about $100 and any handy man can build one, build a sturdy frame, especially where you want the compressor mounted, add sides a door etc and insulate that with the proper sound deadening insulation (Thats the biggest cost) pull some old rubber mounts of something or buy a few so you can mount your compressor to the frame, mount your air filter on the outside and run a pipe to the compressor through the side and seal with silicone, run you air outlet into a manifold which you bolt on the side giving you multi airpoints. Thus far the rubber mount, the soundproof insulation should be enough to deal with 90% of the noise issue, if you use it for extended periods a filter on top of the box with a fan mounted to draw out the heat and your pretty much have silenced any compressor at 1/4 of the cost of a silent compressor which ultimately will be noisier than what you just made..Oh and if it still squeeks a bit much noise you can then sticky tape 200 mm foam insulation to the side of it..After all that you will wonder if its actually on or not..

Soz for the long explanation but a good silencing box solves 90% of peeps compressor noise issues, just remember that subsonic noise as for most neighbours, thats more annoying than real heard noise LOL..