Greetings....
I am preparing to re-paint some pipe fencing, perhaps old oil pipe, but not sure.
It is currently a white that is pretty badly oxidized, with rust spots and chipping.
From internet searches I have decided to scrape and use ospho on the rust spots.
My question to the forum members is once I have prepped the pipe, what paint should I use, do I need a primer?
Thanks for any suggestions in advance.
Sandy

I painted a set of cattle pens by myself one summer over the span of a couple of weeks as a kid.
I think the old man did it just to see if he could break me.

I am interested in this also. Does anyone have actual answers / advice in response to the OP's question concerning primer and paint ?

instead of or in addition to ospho, you might try mixing a little Penetrol with your paint. It goes on a lot easier and also helps minimize rust through.

Thank you....Brazos Bull

We did not use primer. We double coated with basic white outdoor paint.

BrazosBull said:

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I am interested in this also. Does anyone have actual answers / advice in response to the OP's question concerning primer and paint ?

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Primer and/or paint choice seems to be less of an issue than the prepping needed for drill stem.
We finally paid the $$ for sandblasting to bare metal, then an epoxy paint was used. Looks great (minor fading) after 10 yrs.

Go invest in an airless sprayer. We have one from Home Depot. Greco I think. Like $300-500 ish.

Never painted pipe fence, but have stained a bunch of fences with it and painted some rooms. Makes a job a lot easier. Buy the 24-36" extension for the end so you don't have to get as close to the thing you are painting. And not as much bending over.

If it were me, I'd setup a generator and an airless painter in the back of a truck/UTV. Lay down a blue trap cause you know that stuff will spill some. You could have someone drive while another person walked behind the truck painting. Sure, you'll have more overspray and waisted paint, but boy it would go much quicker!

The best luck i had was by cleaning off the loose stuff, using OSPHO, then painting with Hammerite Rust Cap. Do not thin it, do not spray it. Use a brush or small roller to apply.

I just make a deal with grandson that he can't refuse and he scrapes, primes and paints my pipe fence!! Doesn't necessarily like it but the alternative is worse and the job gets done!! No doubt he will remember the jobs I give him long after I'm dead!!!! lol

Our pipe laughed at prep that involved scraping , stout wire (cup) brush on a grinder, rolls of the 2" wide coarse sandpaper, cleaned with paint thinner/Varsol...then used Ospho.

A nephew that used the sandpaper looked like a coal miner after a couple of hours of that fun...



Still was flaking and rusting after a year or two.

Jason Ag.....this is exactly what I was looking for, suggestions for paint and or primer.
Thank you Sir....
Others please chime in!!

Sherwin Williams speced me out a 3 step process of ospho, primer, and final coat. It was a pia and expensive as hell...but lasted 10 years and is barely starting to fade now. If ur interested in the spec...pm me. Also, they make a specialty curved electric wire brush for pipe....also expensive.

Ribeye-Rare said:

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Back when I was involved in manufacturing relatively large steel structures from hot-rolled (mill scale) steel, we tested several of the phosphoric acid based paint pre-treatment products (iron phospate), including Ospho.

We got the best performance from Rust Cure. We found it superior to Ospho, in fact.

Rust Cure Paint Pretreatment

It's actually made in Central Texas.

We'd buy it in cases of (4) 1-gallon jugs for about $20/gallon, and use sprayers and/or rags to apply it.

Since you asked ...

Ideally hot-rolled steel is prepped by sandblasting down to white metal first, then zinc phosphated, then 2-part epoxy primed, and then 2-part urethane top-coated.

But often that expense can't be justified, or just isn't practical because the item is out in the field.

Rust Cure helps greatly in that situation. It may help in yours with your fence posts.

I'd still prime with a heavy-duty single component oil-based primer, and then topcoat them with a single component acrylic or silicone modified oil-based alkyd enamel.

When cost is no object, some guys spring for single component urethanes that cure from the moisture in the air. In that case, you get 2-part urethane performance in a single-component product. Those products can be very tricky to use though.

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This is why I OB... great post and info!! Thanks!

Ribeye-Rare said:

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...
I'd still prime with a heavy-duty single component oil-based primer, and then topcoat them with a single component acrylic or silicone modified oil-based alkyd enamel.

...

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This is exactly what I did and it worked great for over a decade now. Don't forget to wash with tsp and treat with something similar to ospho.

Thanks !

To answer your question. We have lots of pipe fence on our ranch made from oilfield pipe. First. You need to plan on using a wire wheel brush on an angle grinder and get all the old scale and rust off. I highly recommend the Bosch variable speed 4.5 inch angle grinder. The variable speed allows you to turn the speed down and it works much better than turning 15,000 rpm.
Take your time and clean it well. Then just before painting wipe the pipe down with a good grade of lacquer thinner.
Next is decision time depending on your budget. We used Randolph Aircraft Epoxy based primer and sprayed it on.
Then top coat was Sherwin Williams industrial coating that they make for offshore rigs.
We have pipe fencing on the ranch that was done with above process and are scale and rust free after 10 years or more.
If on a budget I recommend Rust Oleum Rusty Metal Primer then top coat with Rust Oleum Aluminum paint.
Aluminum paint can also double as a primer as well. If you go this route treat the pipe after grinder cleaning with Ospho before coating with the Rust Oleum Aluminum paint.
A paint job is no better than the substrate below it so grinding the pipe with a wire brush, then wiping the pipe with lacquer thinner before applying your first primer coat seems to be the key.
If you bought decent outfield pipe it will paint and last just as well as any other pipe.
I wish I had a dollar for every foot of pipe I have painted....I could retire early!
Hope this helps you.
If you decide to spray the Randolph Epoxy primer make sure you wear a quality respirator that fits correctly.

Jason Ag said:

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The best luck i had was by cleaning off the loose stuff, using OSPHO, then painting with Hammerite Rust Cap. Do not thin it, do not spray it. Use a brush or small roller to apply.

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This is exactly my method. The Hammerite paint is a pain but works well. Good luck!

Thanks for the very thoughtful post "gunny 456"
I think I have a pretty good idea of how I will approach my project. Thanks to all for your input.
Sandy

Dont forget the zinc