Cleaning Steel Prior to Painting?

[Jim Thompson]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

...Jim Thompson

 

[Tim Wescott]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

You want phosphoric acid, IIRC. It's the stuff in Naval Jelly, at any
rate. It cleans the rust and leaves a mild, paintable, anti-corrosion
film behind.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html

 

[D from BC]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

...Jim Thompson

You could try a wire wheel on a drill..
http://www.doityourself.com/invt/u201593
The link is just an example....
D from BC

 

[Michael A. Terrell]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

Ospho


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[MooseFET]

You want phosphoric acid, IIRC. It's the stuff in Naval Jelly, at any
rate. It cleans the rust and leaves a mild, paintable, anti-corrosion
film behind.

I've heard that oxalic acid is better.

This is also claimed to work:
http://www.instructables.com/id/E17UQMY28PEQ6T2A5Z?ALLSTEPS

 

[[email protected]]

I've heard that oxalic acid is better.

This is also claimed to work:http://www.instructables.com/id/E17UQMY28PEQ6T2A5Z?ALLSTEPS

Phosphoric acid apparently passivates the surface. From the point of
view of removing oxidised iron, oxalic acid might be better - oxalic
acid forms a very stable complex with ferric ions, so the
electrochemical potential pulling the ferric ions into solution is
very high.

I never found that passivating old rust did very much good - the
approach that worked best for me over the long term involved getting
rid of as much of the rust as possible, with a wire brush followed by
coarse emery paper to leave a reasonably bright surface, which I then
protected with a coat of zinc-rich primer (paint loaded with particles
of metallic zinc) followed by a coat of regular primer. The zinc
particles presumably act as sacrificial electrodes, and seem to keep
the iron rust free for many years.

 

[Barry Lennox]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

I'd use a flap wheel or sanding disk to remove 90% of the crap. Maybe
a slosh over with phosphoric acid or one of the off-the-shelf
versions, then a coat of "Hammerite" works wonders. Limited colors,
but it's pretty tough.

Barry

 

[Mick]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

...Jim Thompson

Kill rust?
Mick C

 

[John Ferrell]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

...Jim Thompson

If it has not reached the flaking point Rustoluem spray paint will do
just fine. Follow the instructions on the can. It will take at least
overnight to dry. If it has reached the flaking point mechanical
removal of the rust is advised!

John Ferrell W8CCW
"Life is easier if you learn to
plow around the stumps"

 

[Rich Grise]

Phosphoric acid apparently passivates the surface. From the point of
view of removing oxidised iron, oxalic acid might be better - oxalic
acid forms a very stable complex with ferric ions, so the
electrochemical potential pulling the ferric ions into solution is
very high.

I never found that passivating old rust did very much good - the
approach that worked best for me over the long term involved getting
rid of as much of the rust as possible, with a wire brush followed by
coarse emery paper to leave a reasonably bright surface, which I then
protected with a coat of zinc-rich primer (paint loaded with particles
of metallic zinc) followed by a coat of regular primer. The zinc
particles presumably act as sacrificial electrodes, and seem to keep
the iron rust free for many years.

This sounds kinda kewl:
http://www.google.com/search?hl=en&q=electrolytic+de-ruster

Cheers!
Rich

 

[default]

On Wed, 04 Jul 2007 01:19:37 -0700, [email protected] wrote:

Snip

I never found that passivating old rust did very much good - the
approach that worked best for me over the long term involved getting
rid of as much of the rust as possible, with a wire brush followed by
coarse emery paper to leave a reasonably bright surface, which I then
protected with a coat of zinc-rich primer (paint loaded with particles
of metallic zinc) followed by a coat of regular primer. The zinc
particles presumably act as sacrificial electrodes, and seem to keep
the iron rust free for many years.

I agree with that. I never had much success with Naval Jelly or
Oxalic acid (also used to clean/dissolve wood) or "Extend." Best way
is do the work of removing the rust then prime with zinc primer then
paint with a high quality oil base paint (if you can still find it)

Incidentally, the two techniques priming and passivating aren't
necessarily compatible. Small amounts of residual acid play havoc
with zinc primers.

 

[HapticZ]

try a litre of classic coca cola

it erodes everything, including teeth.

 

[Martin Riddle]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

...Jim Thompson

I second the navel jelly. Then Murtic acid for heavy jobs

BTW, use rustolium and their primer. If not I really like the Painters Touch
paint, really good UV protection.

Cheers

 

[Joerg]

When I put out the flag today ...

Good man. We went to a parade today, out in the boonies. Scouts,
farmers, tractors, horses and so on. Then the Weber was fired up.
Country living is good. But after a parade with lots of horses it does
smell a bit ....

... I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

I'd go with John's advice. Brush off any coarse stuff with a wire brush,
then a fresh coat of your favorite color Rustoleum. Ace has some good
stuff as well. Initially I thought that there is no free lunch when it
comes to rust but my wife convinced me. She regularly spray-paints
rusted lawn chairs and afterwards the paint lasts years. And this is
Cahleefohniah where is does rain and freeze and all that.

 

[Jimmie D]

When I put out the flag today I noticed that the steel wall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly that cleaning steel in a mild acid solution is
the best treatment to remove the rust, then prime and paint?

...Jim Thompson

By a vinyl holder. Wife picked up 2 for less than $2 ea. Otherwise remove
the rust mechanically, finish up wiht some naval jelly, prime and paint.

Not worth the two bucks to me.
When mine doesnt have a flag in it it holds a support for hanging flower
pots

 

[mpm]

When I put out the flag today I noticed that the steel wall bracket is
rusting...

I could say that the rust is indicative of the current general state
of affairs in the nation, and that maybe the rust and the locality are
somewhat unrelated....

But I think that might just annoy Jim, and somehow, I'm already on his
"bad" side..

Instead, I will tell you something I learned from my brother the other
day that I totally did not know. --
US Flags with Gold Fringe around the edges appearently means that
maritime law is practiced wherever it is on display.
I have to research this further to make sure he got it right, and that
my 3rd or 4th hand interpretation is right.

I need to know this so next time I'm in Virginia paying one of those
$3K speeding tickets, I can ask them to go get a real flag before I
accept the verdict (...unless I'm speeding in my boat, that is.)

-mpm

Oh: For a flag holder, I would think just about any "treatment" would
last a suitably long time, unless you're passing this on to the
grandchildren or something... Or ditch it and get one made of solid
brass.

 

[Michael A. Terrell]

I could say that the rust is indicative of the current general state
of affairs in the nation, and that maybe the rust and the locality are
somewhat unrelated....

But I think that might just annoy Jim, and somehow, I'm already on his
"bad" side..

Instead, I will tell you something I learned from my brother the other
day that I totally did not know. --
US Flags with Gold Fringe around the edges appearently means that
maritime law is practiced wherever it is on display.
I have to research this further to make sure he got it right, and that
my 3rd or 4th hand interpretation is right.

I need to know this so next time I'm in Virginia paying one of those
$3K speeding tickets, I can ask them to go get a real flag before I
accept the verdict (...unless I'm speeding in my boat, that is.)

-mpm

Oh: For a flag holder, I would think just about any "treatment" would
last a suitably long time, unless you're passing this on to the
grandchildren or something... Or ditch it and get one made of solid
brass.

Come on. Everyone knows that Jim prefers solid gold.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[g]

When I put out the flag today I noticed that thesteelwall bracket is
rusting, in spite of this being Arizona, where rust is forbidden ;-)

Do I remember correctly thatcleaningsteelin a mild acid solution is
the best treatment to remove the rust, then prime and paint?

...Jim Thompson

I would just watch it rust. Might take a while.

The one thing thats best to do after prep, is use a self etching
primer. You have to do this when painting a car as I have done several
times, otherwise rust will form and creep.

greg