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The pipes that connect your home’s natural gas lines for appliances like your water heaters or your furnaces are typically made of either black iron or galvanized iron pipes.
They are both extremely heat tolerant which makes them ideal vehicles for a substance as volatile as natural gas.
Between the two pipes, galvanized iron pipes have been more popular for their zinc coatings that are effective in preventing rust.
However, over longer periods of time this coating proves to be quite the hindrance as zinc flakes begin to peel off and block your plumbing.
In comparison, black iron pipes are a far better alternative for the long run. They don’t need extra cleaning to fish out zinc blockages and they’re more durable.
While they are more prone to rusting and erosion, this can definitely be managed with regular cleaning and rust-preventive measures.
Read on to learn more about how to clean black iron pipe effectively and keep them rust-free.
What is the Black Coating on an Iron Pipe?
Ironically enough, these pipes are black because they don’t have an actual coating.
They are typically made of pure iron or steel, both of which react with atmospheric oxygen for iron oxide.
This oxide that deposits along the outer surface of the pipes is what gives them their characteristic black color.
If the pipes were actually to be coated with either zinc or paint like galvanized steel pipes, then they would in fact not be in black in color.
Can You Remove the Coating from a Black Iron Pipe?
Because the black color is not actually a coating, it is more difficult to remove the color from the pipe than with other pipe models.
However, it is not impossible either.
Rubbing them with mineral spirits and then sanding down on the pipes is one way to get to the shiny undersurface of your iron pipes.
But this does cut down to the metal and can decrease your pipe’s shelf life as it speeds up the erosion process.
Another more effective technique is to use Jasco paint and epoxy removers.
The iron that you polish out is bound to form the oxide again, so you’ll be required to repeatedly maintain cleaning protocols. It’s up to you whether it’s worth the effort.
While you can technically remove the black coating from your pipes whether or not you should is an entirely different matter.
How to Clean Black Iron Pipe
There is no particularly special procedure for cleaning your black iron pipes. Whatever routine you might have for your other pipes will work perfectly fine for these as well. A basic pipe cleaning routine is covered below.
The only thing to note is that black iron pipes are very often used for gas lines.
It is thus imperative that you use non-flammable cleaners to avoid any major explosions or accidents.
However, if you’re new to the pipe-cleaning scene and don’t really have a technique of your own, there’s no need to fret — we’ve got your back.
Here are some of the basics of how to clean black iron pipe:
1. Get the Black Iron Pipes Wet
Pour some warm water over your black iron pipes and try to scrub the dirt off.
Make sure that the water is not too hot as that can cause an uneven expansion in the pipe’s metal and make it all the more prone to leaking or bursting.
2. Scrub Away
Using a plastic scrubber should suffice for most purposes, but if the dirt is particularly stubborn, you can also try a pad of steel wool.
If you do decide to use steel wool, make sure you’re not using it on a pipe that’s being used as a gas line.
Metal on metal can result in sparks that will set alight any traces of gas on the pipes’ outer surface. If your pipe has a slow leak, that’d be an even bigger hazard.
3. Rust Removal Prep
To remove any rust, you have to a do bit more of a deep clean.
After ensuring that the water or gas supply is securely turned off, use a wrench to unscrew the pipes and separate them from each other.
For the method below, you’ll need a battery charger.
4. Make Rust Removal Solution
Fill a bucket with water until the water line is at least six inches below the bucket’s rim.
Mix in some washing soda, around 1 tbsp. for every gallon of water, a little at a time so that you don’t get it on your clothes or yourself.
You can also try lye if you want a stronger conducting agent, but make it a point to wear goggles and gloves.
Lye is highly acidic and can cause chemical burns if it comes in contact with your skin. Exercise caution when working with it.
5. Find an Anode
Look for an old piece of metal to use as an anode (one of the terminals in an electric circuit).
It should be large enough that one end can stick out above the waterline and over the bucket’s rim.
You can use a squeeze clamp or a piece of coated wire to hold it in place in an upright position.
6. Connect the Anode
One set of clamps go on the pipe and the anode respectively.
7. Add the Pipe
Once you’re set with the set-up it’s time to get started on the actual circuit.
8. Complete the Circuit
Connect the red wire of the battery to the copper wire running from the black iron pipe.
Connect the black wire to the one running from the anode metal.
While doing so, make sure that the battery charger is not plugged in.
It is also advisable to get through this bit of the protocol while wearing a pair of heavy-duty gloves or oven mitts.
Though most battery chargers come with built-in safety features, the current from a battery of this size is capable of delivering a damaging shock.
9. Power the Circuit
After making sure one last time that the red and black wires are properly fixed, plug in your battery charger.
Wait and watch the setup until you see small bubbles start to rise from the surface of the pipes. This means that your circuit has been properly connected and is running fine.
If you don’t see these bubbles forming, then there’s probably a loose connection in the circuit.
Unplug the battery and recheck all your connections; your circuit should work better this time around.
10. Let the Rust Bubble Away
Once you see the bubbles start to rise from the pipes, leave the circuit to run for a couple of hours.
There is no exact time limit for this, but in general, for 2-3cms of rusting 4 hours should suffice.
The more rust you have, the longer you should let the circuit run.
11. Depower the Circuit
After you’ve let the pipes stay in the solution long enough, unplug the charger.
Wait a couple of minutes to let the solution cool down first. Letting the circuit run for very long can generate quite a lot of heat.
12. Wash the Black Iron Pipes
Wash the pipes until running tap water and scrub at them with a brush to remove the now loose layer of rust.
The rust should be coming off in large clumps and flakes, and shouldn’t take too much effort to remove.
13. Drying Time
Pat them down with a towel or some tissues and let the pipes dry out fully before putting them back together.
How Do You Keep a Black Iron Pipe from Rusting?
It is certainly helpful to have know-how on how to clean black iron pipe. However, you might be better off learning how to maintain them to prevent rusting and other damage.
Although there isn’t a lot you can do against the natural forces of erosion and wear, rusting is definitely a phenomenon you can keep in check.
You can easily get competitive rust-inhibitive primers online or at your local DIY stores.
Apply the primer in thin coats and maintain multiple layers for the best maintenance.
Touching up paint is also a very effective tip to prevent rust. Oftentimes, rust develops first at sites of peeling paint.
If this issue is nipped in the bud, it saves you a great deal of time and capital down the road.