Hey,
I bought a compressor from a garage sale yesterday.
Paid $20, seems to be between 13 and 20 gallons.
What I wanted was an oil type compressor that uses a belt.

I could not take the oil less type of noise anymore.

I thought I was taking a risk, pretty rusted on the outside, but didn't
appear deeply rusted. I shook the thing did not hear water in it (WRONG)...


When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank? Where I used to live we
had a scales air compressor place nearby but they closed... I don't find
any of them around any more.. not close by.
The rust on the outside is all superficial and can be sanded and painted
.... I need to get into the tank with a 3/4 square end and see..
Anyone have some real info on how to treat this?

Thanks.

--
Jeff

On 5/5/13 2:53 PM, woodchucker wrote:
When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank?


I guess I don't understand what's to save.
Does it still compress air?
You drained out the water.
Put a filter on the output and use it.

I think we'd all be surprised by how much water and rust are on the
inside of the tanks we use every day. :-)


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 5/5/2013 4:56 PM, -MIKE- wrote:
On 5/5/13 2:53 PM, woodchucker wrote:
When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank?


I guess I don't understand what's to save.
Does it still compress air?
You drained out the water.
Put a filter on the output and use it.

I think we'd all be surprised by how much water and rust are on the
inside of the tanks we use every day. :-)


Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

--
Jeff

On 5/5/2013 5:16 PM, woodchucker wrote:
On 5/5/2013 4:56 PM, -MIKE- wrote:
On 5/5/13 2:53 PM, woodchucker wrote:
When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank?


I guess I don't understand what's to save.
Does it still compress air?
You drained out the water.
Put a filter on the output and use it.

I think we'd all be surprised by how much water and rust are on the
inside of the tanks we use every day. :-)


Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

I also remember that there used to be an additive to tanks to protect them.
I knew what it was 30 years ago.

Might be too late, but anyone know what the name is.

--
Jeff

On 5/5/13 4:21 PM, woodchucker wrote:
On 5/5/2013 5:16 PM, woodchucker wrote:
On 5/5/2013 4:56 PM, -MIKE- wrote:
On 5/5/13 2:53 PM, woodchucker wrote:
When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most
rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank?


I guess I don't understand what's to save.
Does it still compress air?
You drained out the water.
Put a filter on the output and use it.

I think we'd all be surprised by how much water and rust are on the
inside of the tanks we use every day. :-)


Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

I also remember that there used to be an additive to tanks to protect them.
I knew what it was 30 years ago.

Might be too late, but anyone know what the name is.


I'm going on 13 years with my current compressor and it work like
the day I bought it. I think i remember letting a few ounces of water
out of it several years ago. Yes, it was brown.

To the best of my knowledge, emptying water is important to keep water
out of your pneumatic tools and the finish material you might be
spraying using the compressor.

I don't think it affects the performance of the compressor.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 5/5/2013 6:45 PM, -MIKE- wrote:
On 5/5/13 4:21 PM, woodchucker wrote:
On 5/5/2013 5:16 PM, woodchucker wrote:
On 5/5/2013 4:56 PM, -MIKE- wrote:
On 5/5/13 2:53 PM, woodchucker wrote:
When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most
rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank?


I guess I don't understand what's to save.
Does it still compress air?
You drained out the water.
Put a filter on the output and use it.

I think we'd all be surprised by how much water and rust are on the
inside of the tanks we use every day. :-)


Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

I also remember that there used to be an additive to tanks to protect
them.
I knew what it was 30 years ago.

Might be too late, but anyone know what the name is.


I'm going on 13 years with my current compressor and it work like
the day I bought it. I think i remember letting a few ounces of water
out of it several years ago. Yes, it was brown.

To the best of my knowledge, emptying water is important to keep water
out of your pneumatic tools and the finish material you might be
spraying using the compressor.

I don't think it affects the performance of the compressor.


Years ago I read about a tank having a catastrophic failure. It didn't
just pinhole, it blew from rust.

So I worry, I wanted to bring this into the basement. My current one
wakes me up at night when I forget to shut it...

This one will be quieter if I forget. But I need to know it will be ok.
--
Jeff

On Sun, 05 May 2013 17:45:26 -0500, -MIKE- wrote:

To the best of my knowledge, emptying water is important to keep water
out of your pneumatic tools and the finish material you might be
spraying using the compressor.

I don't think it affects the performance of the compressor.

Well, it might just be the normal corporate CYA, but every compressor
manual I've seen says to drain on a regular basis - like every time if
you use it infrequently.

--
When fascism comes to America, it will be wrapped in the flag and
carrying a cross.

On 05/05/2013 02:21 PM, woodchucker wrote:
On 5/5/2013 5:16 PM, woodchucker wrote:
On 5/5/2013 4:56 PM, -MIKE- wrote:
On 5/5/13 2:53 PM, woodchucker wrote:
When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most
rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank?


I guess I don't understand what's to save.
Does it still compress air?
You drained out the water.
Put a filter on the output and use it.

I think we'd all be surprised by how much water and rust are on the
inside of the tanks we use every day. :-)


Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

I also remember that there used to be an additive to tanks to protect them.
I knew what it was 30 years ago.

Might be too late, but anyone know what the name is.

Don't know about that stuff, but I put the HF automatic compressor drain
on mine:

http://www.harborfreight.com/catalogsearch/result?q=automatic+compressor+drain

I did have to fart around and replace the plastic tubing with copper
tubing. It's been working fine for about 12 years.



--
"Socialism is a philosophy of failure,the creed of ignorance, and the
gospel of envy, its inherent virtue is the equal sharing of misery"
-Winston Churchill

Doug Winterburn wrote:

Don't know about that stuff, but I put the HF automatic compressor
drain on mine:

http://www.harborfreight.com/catalogsearch/result?q=automatic+compressor+drain

I did have to fart around and replace the plastic tubing with copper
tubing. It's been working fine for about 12 years.

I tried two of those damned things and finally went back to an elbow, a
valve and a length of pipe. I too had replaced the cheap hose with brake
line (in my case), but the damned valves both failed after only a couple or
a few weeks.

--

-Mike-

On 5/5/2013 5:16 PM, woodchucker wrote:
On 5/5/2013 4:56 PM, -MIKE- wrote:
On 5/5/13 2:53 PM, woodchucker wrote:
When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most rusted
water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank?


I guess I don't understand what's to save.
Does it still compress air?
You drained out the water.
Put a filter on the output and use it.

I think we'd all be surprised by how much water and rust are on the
inside of the tanks we use every day. :-)


Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

I would believe that the question is not how much water or how much
rust, but what is the remaining thickness of the metal making up the
tank. If the tank has sit for years has the bottom nearly rusted through?

If it rusted and significantly decreased the thickness of the tank wall
is it general or is it such that when it fails it will pin hole and leak
slowly or fail catastrophically.

I have never seen a tank fail, but.................

Keith Nuttle wrote in
:


I would believe that the question is not how much water or how much
rust, but what is the remaining thickness of the metal making up the
tank. If the tank has sit for years has the bottom nearly rusted
through?

If it rusted and significantly decreased the thickness of the tank
wall is it general or is it such that when it fails it will pin hole
and leak slowly or fail catastrophically.

I have never seen a tank fail, but.................


I saw one failed intentionally on TV. I think it was Time Warp where
they dropped a 5 or 10 gallon tank off a building on to a spike. Big
noise, lots of pressure released, and the tank went flying. Very fun to
watch.

Puckdropper
--
Make it to fit, don't make it fit.

On Sun, 05 May 2013 17:34:29 -0400, Keith Nuttle
wrote:




If it rusted and significantly decreased the thickness of the tank wall
is it general or is it such that when it fails it will pin hole and leak
slowly or fail catastrophically.

I have never seen a tank fail, but.................


According to the inspector that does out tanks at work, they pin hole
rather than explode. In MA, tanks have to be inspected every two
years. They use an ultrasonic thing and it gives the wall thickness
and can be done while running.

woodchucker wrote:

Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

You'd probably be surprised at how many comressors never get drained, and
sit with water in them for years. Fire it up and use it. You'll find out
if it leaks.

--

-Mike-

woodchucker wrote in
:

Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

When there's a lot of water in the tank, "hadn't been used for years" is waaaaay better than
"used it every week".

Water, by itself, doesn't cause rust. For iron to rust, two things are necessary: water and
oxygen. Once all the oxygen in the tank has been converted to iron oxide, there will be no
further rusting.

Case in point: hydronic (hot water) heating systems -- such as the one in my house --
typically have cast-iron boilers, and many (mine included) have cast-iron radiators as well.
Water normally sits in these systems for *decades* without any damage to the cast-iron
components. Yes, there's some rusting internally, but not much. Once the small amount of
dissolved oxygen is used up, the rusting process stops.

On 5/5/2013 9:51 PM, Doug Miller wrote:
woodchucker wrote in
:

Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

When there's a lot of water in the tank, "hadn't been used for years" is waaaaay better than
"used it every week".

Water, by itself, doesn't cause rust. For iron to rust, two things are necessary: water and
oxygen. Once all the oxygen in the tank has been converted to iron oxide, there will be no
further rusting.

Case in point: hydronic (hot water) heating systems -- such as the one in my house --
typically have cast-iron boilers, and many (mine included) have cast-iron radiators as well.
Water normally sits in these systems for *decades* without any damage to the cast-iron
components. Yes, there's some rusting internally, but not much. Once the small amount of
dissolved oxygen is used up, the rusting process stops.


Makes sense.

--
Jeff

On 5/5/2013 9:51 PM, Doug Miller wrote:
woodchucker wrote in
:

Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

When there's a lot of water in the tank, "hadn't been used for years" is waaaaay better than
"used it every week".

Water, by itself, doesn't cause rust. For iron to rust, two things are necessary: water and
oxygen. Once all the oxygen in the tank has been converted to iron oxide, there will be no
further rusting.

Case in point: hydronic (hot water) heating systems -- such as the one in my house --
typically have cast-iron boilers, and many (mine included) have cast-iron radiators as well.
Water normally sits in these systems for *decades* without any damage to the cast-iron
components. Yes, there's some rusting internally, but not much. Once the small amount of
dissolved oxygen is used up, the rusting process stops.

I would believe that a cast iron boiler is several times thicker that an
air compressor tank. I am sure the radiator is.

Keith Nuttle wrote in :

I would believe that a cast iron boiler is several times thicker that an
air compressor tank. I am sure the radiator is.

Indeed it is. But the water sits there longer, too. The point remains that once the oxygen in the
system is used up, no further oxidation (read: rusting) can take place unless fresh oxygen is
introduced.

On Sun, 05 May 2013 17:16:51 -0400, woodchucker
wrote:





Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

May have been enough oil mixed in there so it was protected. The wet
portion may be better than the dry portion.

On Sun, 05 May 2013 17:16:51 -0400, woodchucker
Well, this tank hadn't been used for years the owner said. I let the
water out of my tank weekly, how long do you let it sit there.
I figure that years of sitting means deep rust inside. Based on the
stink of that water, I'd have to say it's been in there a long time.

In other words, you're afraid that the tank might be on the verge of
blowing up in your face, right?

Compression takes in poor condition, usually develop pinhole leaks
first, which would indicate that it's time for you to replace it. Of
course, you could replace it now, but most people continue to use them
until they start to leak.

In other words, you can use it until there's a problem.

Well, it may have had a pint/quart of water, but the rusting factor would depend on the amount of oxygen reacting with the iron to produce a quantity of rust. In a closed container, the rust may be much less than if contents were exposed to more open air.

Not just open it, but can you remove the whole petcock assembly, without breaking it? What size hole is in the tank, there, 1/2", 3/4"? If you can remove the assembly, rinse out the tank, well, then rinse with denatured alcohol. Allow to dry, as best it can, before reinstalling the petcock.

If I had a questionably badly rusted tank, I might entertain the idea of rinsing/sloshing the bottom of the tank with muratic acid, to see what all might be washed out. Rinse with water, afterwards. I would think the very bottom is rusted the most, if significantly.

Sonny

On Sun, 5 May 2013 17:05:31 -0700 (PDT), Sonny
wrote:

Well, it may have had a pint/quart of water, but the rusting factor would depend on the amount of oxygen reacting with the iron to produce a quantity of rust. In a closed container, the rust may be much less than if contents were exposed to more open air.

An air tank has plenty of oxygen in it. High pressure == more oxygen.

Not just open it, but can you remove the whole petcock assembly, without breaking it? What size hole is in the tank, there, 1/2", 3/4"? If you can remove the assembly, rinse out the tank, well, then rinse with denatured alcohol. Allow to dry, as best it can, before reinstalling the petcock.

It's just going to get "wet" again, at the first use. It's sorta
unavoidable, unless you live in AZ. ;-)

If I had a questionably badly rusted tank, I might entertain the idea of rinsing/sloshing the bottom of the tank with muratic acid, to see what all might be washed out. Rinse with water, afterwards. I would think the very bottom is rusted the most, if significantly.

That sounds like a really bad idea. The rust isn't going to hurt
anything more than it already has. HCL does corrode steel, which is
*not* useful. If the worry is polluting the air stream, filter it. If
that doesn't work, filter it some more. ;-)

On 5/5/2013 8:05 PM, Sonny wrote:
Well, it may have had a pint/quart of water, but the rusting factor would depend on the amount of oxygen reacting with the iron to produce a quantity of rust. In a closed container, the rust may be much less than if contents were exposed to more open air.

Not just open it, but can you remove the whole petcock assembly, without breaking it? What size hole is in the tank, there, 1/2", 3/4"? If you can remove the assembly, rinse out the tank, well, then rinse with denatured alcohol. Allow to dry, as best it can, before reinstalling the petcock.

If I had a questionably badly rusted tank, I might entertain the idea of rinsing/sloshing the bottom of the tank with muratic acid, to see what all might be washed out. Rinse with water, afterwards. I would think the very bottom is rusted the most, if significantly.

Sonny

Sounds like that might not be a bad idea. Gotta see if I can get a 3/4
square drive to remove the 2 plugs, it would allow me to ,
the petcock I usually replace with 90 street and galv pipe to a ball valve.
Don't understand petcocks.. pain the ass and the ball is worth the money
to quickly release the water.

how do I neutralize the muriatic acid in the tank after, just water or
baking soda... Will that clean off most of the loose rust?

--
Jeff

On Sunday, May 5, 2013 8:57:31 PM UTC-5, woodchucker wrote:
Sounds like that might not be a bad idea. how do I neutralize the muriatic acid in the tank after, just water or baking soda...

Flush with water. It shouldn't take much acid (1-2 cups) to rinse/slosh the bottom of the tank, where there would likely be the most rust. Concrete is cleaned with muratic acid and simply rinsed with water. The old saying is to add acid to water, to prevent a splattering reaction when mixing the two. In this situation, adding water to the acid (to neutralize it), inside the tank, shouldn't be a problem, plus it would be difficult to pour out the acid, first, into a safe container without having it pour irradically from the petcock hole. Further, pour the mix into a 5 gal bucket of water, to further dilute it.

Will that clean off most of the loose rust?

Maybe/yes, to some extent. I've used it to assist in removing rust on stuff at home(shop) and used it on (our past) boat dock surfaces. Since you can't readily see inside the tank, we don't know if there is significant rust in there, or not. Muratic acid is more readily available, I think, and will help loosen at least some rust without having to scrub, since you can't readily scrub the inside. Any potential loose rust may block the petcock, in the future, so removing the most you can is preferrable. Using acid is the easiest way, IMO, hence my entertaining the idea of using the acid as a "rinse" or possible (assistant) rust remover.

Summer jobs, during college days, I worked on a dredge boat/barge along the Gulf coast. There were times when we'd clean parts of the deck for repainting. An acid was used to help remove (or treat?) the rusted areas. I don't recall what acid was used. We'd slosh it on, do some minimal scrubbing, then rinse with water. On tough or deeply rusted areas, we'd use a grinder to remove the rust, best we could. Apparently the acid "treatment" did some kind of good.

Muratic acid is pretty potent. If spilled on the outside of the tank, it will likely peel the paint off, fast.

Sonny

On Sun, 5 May 2013 17:05:31 -0700 (PDT), Sonny
wrote:

Well, it may have had a pint/quart of water, but the rusting factor would depend on the amount of oxygen reacting with the iron to produce a quantity of rust. In a closed container, the rust may be much less than if contents were exposed to more open air.

Not just open it, but can you remove the whole petcock assembly, without breaking it? What size hole is in the tank, there, 1/2", 3/4"? If you can remove the assembly, rinse out the tank, well, then rinse with denatured alcohol. Allow to dry, as best it can, before reinstalling the petcock.

If I had a questionably badly rusted tank, I might entertain the idea of rinsing/sloshing the bottom of the tank with muratic acid, to see what all might be washed out. Rinse with water, afterwards. I would think the very bottom is rusted the most, if significantly.

Sonny
Buy , rent, or borrow an "inspection camera" - remove a fitting and
poke the camra in to see what it looks like. If you can't tell, rince
the tank out untill it is clean and try again. Any significant pitting
will show up.

woodchucker wrote:



So what chance do I have of saving this tank? Where I used to live we
had a scales air compressor place nearby but they closed... I don't
find any of them around any more.. not close by.
The rust on the outside is all superficial and can be sanded and
painted ... I need to get into the tank with a 3/4 square end and
see.. Anyone have some real info on how to treat this?


You can buy sealers that you can pour into the tank after you dry it out
(throw some rocks in it, shake them around good first). Look for gas tank
sealers. A compressor tank will go for years like that though. Hard to say
without seeing the tank, knocking on it to see how the steel sounds, etc.,
but just because it poured out rusty water is not cause to get too worried
just yet.

--

-Mike-

On 5/5/2013 6:46 PM, Mike Marlow wrote:
woodchucker wrote:



So what chance do I have of saving this tank? Where I used to live we
had a scales air compressor place nearby but they closed... I don't
find any of them around any more.. not close by.
The rust on the outside is all superficial and can be sanded and
painted ... I need to get into the tank with a 3/4 square end and
see.. Anyone have some real info on how to treat this?


You can buy sealers that you can pour into the tank after you dry it out
(throw some rocks in it, shake them around good first). Look for gas tank
sealers. A compressor tank will go for years like that though. Hard to say
without seeing the tank, knocking on it to see how the steel sounds, etc.,
but just because it poured out rusty water is not cause to get too worried
just yet.


"just yet". LOL.
I like that. It's kinda like when your dentist says, "OOPS!

woodchucker wrote:
Hey,
I bought a compressor from a garage sale yesterday.
Paid $20, seems to be between 13 and 20 gallons.
What I wanted was an oil type compressor that uses a belt.

I could not take the oil less type of noise anymore.

I thought I was taking a risk, pretty rusted on the outside, but
didn't appear deeply rusted. I shook the thing did not hear water in
it (WRONG)...

When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most
rusted water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank? Where I used to live we
had a scales air compressor place nearby but they closed... I don't
find any of them around any more.. not close by.
The rust on the outside is all superficial and can be sanded and
painted ... I need to get into the tank with a 3/4 square end and
see.. Anyone have some real info on how to treat this?

Thanks.

From Wikipedia:

--- begin quote
Phosphoric acid may be used as a "rust converter", by direct application to
rusted iron, steel tools, or surfaces. The phosphoric acid converts
reddish-brown iron(III) oxide, Fe2O3 (rust) to black ferric phosphate,
FePO4.

"Rust converter" is sometimes a greenish liquid suitable for dipping (in the
same sort of acid bath as is used for pickling metal), but it is more often
formulated as a gel, commonly called "naval jelly". It is sometimes sold
under other names, such as "rust remover" or "rust killer". As a thick gel,
it may be applied to sloping, vertical, or even overhead surfaces.

After treatment, the black ferric-phosphate coating can be scrubbed off,
leaving a fresh metal surface. Multiple applications of phosphoric acid may
be required to remove all rust. The black phosphate coating can also be left
in place, where it will provide moderate further corrosion resistance (such
protection is also provided by the superficially similar Parkerizing and
blued electrochemical conversion coating processes).

--- end quote

This is how "black pipe" (used for natural gas distribution) is created.



And, from one blogger:

"Look for it as Metal Prep oluton. It's available at any lumber yard, borg,
or hardware store in quarts and gallons in plastic bottles. I use Jasco out
of blind brand loyalty but it' a good consistant product. It has tuff in it
that makes it work better than the plain acid. I dilute it 10 to 1 in a 5
gallon pail. When the blue color fades the acid has pooped out so add more.

"It's sewer safe when exhausted. Or since the spent solution is mostly iron
phosphate it makes good fertilizer. Run it through a proportioning squirt
nozzle and water your flowers."

On 5/5/2013 9:56 PM, HeyBub wrote:
woodchucker wrote:
Hey,
I bought a compressor from a garage sale yesterday.
Paid $20, seems to be between 13 and 20 gallons.
What I wanted was an oil type compressor that uses a belt.

I could not take the oil less type of noise anymore.

I thought I was taking a risk, pretty rusted on the outside, but
didn't appear deeply rusted. I shook the thing did not hear water in
it (WRONG)...

When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most
rusted water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank? Where I used to live we
had a scales air compressor place nearby but they closed... I don't
find any of them around any more.. not close by.
The rust on the outside is all superficial and can be sanded and
painted ... I need to get into the tank with a 3/4 square end and
see.. Anyone have some real info on how to treat this?

Thanks.

From Wikipedia:

--- begin quote
Phosphoric acid may be used as a "rust converter", by direct application to
rusted iron, steel tools, or surfaces. The phosphoric acid converts
reddish-brown iron(III) oxide, Fe2O3 (rust) to black ferric phosphate,
FePO4.

"Rust converter" is sometimes a greenish liquid suitable for dipping (in the
same sort of acid bath as is used for pickling metal), but it is more often
formulated as a gel, commonly called "naval jelly". It is sometimes sold
under other names, such as "rust remover" or "rust killer". As a thick gel,
it may be applied to sloping, vertical, or even overhead surfaces.

After treatment, the black ferric-phosphate coating can be scrubbed off,
leaving a fresh metal surface. Multiple applications of phosphoric acid may
be required to remove all rust. The black phosphate coating can also be left
in place, where it will provide moderate further corrosion resistance (such
protection is also provided by the superficially similar Parkerizing and
blued electrochemical conversion coating processes).

--- end quote

This is how "black pipe" (used for natural gas distribution) is created.



And, from one blogger:

"Look for it as Metal Prep oluton. It's available at any lumber yard, borg,
or hardware store in quarts and gallons in plastic bottles. I use Jasco out
of blind brand loyalty but it' a good consistant product. It has tuff in it
that makes it work better than the plain acid. I dilute it 10 to 1 in a 5
gallon pail. When the blue color fades the acid has pooped out so add more.

"It's sewer safe when exhausted. Or since the spent solution is mostly iron
phosphate it makes good fertilizer. Run it through a proportioning squirt
nozzle and water your flowers."


So if I can't scrub it off, will it still work?

--
Jeff

On Sun, 05 May 2013 22:08:37 -0400, woodchucker
wrote:

On 5/5/2013 9:56 PM, HeyBub wrote:
woodchucker wrote:
Hey,
I bought a compressor from a garage sale yesterday.
Paid $20, seems to be between 13 and 20 gallons.
What I wanted was an oil type compressor that uses a belt.

I could not take the oil less type of noise anymore.

I thought I was taking a risk, pretty rusted on the outside, but
didn't appear deeply rusted. I shook the thing did not hear water in
it (WRONG)...

When I got it home still did not hear water in it...
opened up the petcock after charging it up and holy crap the most
rusted water... and probably a pint to quart of water came out.


So what chance do I have of saving this tank? Where I used to live we
had a scales air compressor place nearby but they closed... I don't
find any of them around any more.. not close by.
The rust on the outside is all superficial and can be sanded and
painted ... I need to get into the tank with a 3/4 square end and
see.. Anyone have some real info on how to treat this?

Thanks.

From Wikipedia:

--- begin quote
Phosphoric acid may be used as a "rust converter", by direct application to
rusted iron, steel tools, or surfaces. The phosphoric acid converts
reddish-brown iron(III) oxide, Fe2O3 (rust) to black ferric phosphate,
FePO4.

"Rust converter" is sometimes a greenish liquid suitable for dipping (in the
same sort of acid bath as is used for pickling metal), but it is more often
formulated as a gel, commonly called "naval jelly". It is sometimes sold
under other names, such as "rust remover" or "rust killer". As a thick gel,
it may be applied to sloping, vertical, or even overhead surfaces.

After treatment, the black ferric-phosphate coating can be scrubbed off,
leaving a fresh metal surface. Multiple applications of phosphoric acid may
be required to remove all rust. The black phosphate coating can also be left
in place, where it will provide moderate further corrosion resistance (such
protection is also provided by the superficially similar Parkerizing and
blued electrochemical conversion coating processes).

--- end quote

This is how "black pipe" (used for natural gas distribution) is created.



And, from one blogger:

"Look for it as Metal Prep oluton. It's available at any lumber yard, borg,
or hardware store in quarts and gallons in plastic bottles. I use Jasco out
of blind brand loyalty but it' a good consistant product. It has tuff in it
that makes it work better than the plain acid. I dilute it 10 to 1 in a 5
gallon pail. When the blue color fades the acid has pooped out so add more.

"It's sewer safe when exhausted. Or since the spent solution is mostly iron
phosphate it makes good fertilizer. Run it through a proportioning squirt
nozzle and water your flowers."


So if I can't scrub it off, will it still work?
Yes - better than scrubbing it off. The iron phosphate helps prevent
further rusting.

I know it isn't near as much of an adventure when compared to acid
washes, cleaning rust and sealing, ultrasound inspections, and all
other kinds of solutions, but why not just buy a new tank and be done
with it?

http://tinyurl.com/cptqhe4

You could even wait for the ever present 20% off coupon.

We have done this to several compressors over the years. I have seen
tanks leak, but never rupture. What I see is tanks damaged badly
enough from dropping the compressors while loading or unloading them
for daily use, loading material on top of them, and then just plain
wear and tear from carrying them from job to job.

To do this easily, the original tank assembly is bypassed or removed,
and in some cases the motor/head is mounted to something else, and
this tank along with a manifold is used to replace the original. You
cannot mount a motor/head to this as purchased, so this is a perfect
time to put the compressor in its own little corner and the tank out
of the way. All you need to connect the two is inexpensive air hose.

Not as much fun as some of the ideas here, but if you leave the old
compressor on its original pinnings, you can be up and running with
one of these tanks in about 20 minutes. I have one of these (bought
mine at Northern) and it works great. I like the extra tank capacity,
too.

Robert