Overview
You’re surrounded by tools
and machines made out of
steel. And when the coatings
on those products crack,
rust starts to bloom and the
battle is on. You can attack
rust early and nip it in the
bud, or you can wait until you
have a full-blown war on your
hands. The choice is yours.
Either way you’ll need a
battle plan and a complete
list of weapons at your disposal.
And that’s why we’re
going to show you the five
ways to defeat rust—three
methods to remove it and
two steps to prevent it from
coming back.
The elbow grease method
1 of 5Match the abrasive to the shape
Use flap discs, fiber discs and sanders on large, flat areas.
Switch to wire wheels for seams, corners and rounded areas.
2 of 5Grinder accessories
A wide range of stripping, grinding and sanding attachments are available for grinders
3 of 5Detail sander
Use a detail sander for corners, tight spots and small details
4 of 5Drill accessories
Drill-mounted wire wheels and stripping discs can be used instead of or in addition to grinders, though they don't have as much power or cover as much surface area.
5 of 5Power sanders
Finishing and random-orbit sanders are also useful tools for rust removal on flatter surfaces.
Grind, sand or scour off the rust
If you’re not into chemicals and you want to remove the paint
along with the rust, use a power tool like a grinder, sander,
oscillating tool or drill. A grinder fitted with a stripping
disc, grinding wheel, fiber or flap disc makes quick
work of heavy rust on large objects. But keep the tool
moving so you don’t gouge the metal. For smaller
jobs, use a traditional sander. To get into small
areas, use a “mouse” sander or an oscillating tool
with a carbide rasp or sanding pad attachment.
Whichever tool you choose, always start with
the coarsest abrasive to get rid of the rust and
pockmarks. Once the rust is gone, switch
to a finer grit to smooth out the swirls and
grooves caused by the coarse grit. For the
smoothest paint job, finish sanding with
400-grit wet/dry paper.
The chemical removal method
1 of 2Select from the "old standbys"
Brush or spray on any of these acid-based removers.
Buy a gel formula for de-rusting vertical surfaces.
2 of 2Buy enough solution to completely cover the rusted part
Clean off any oil or grease before soaking.
Pour the solution in a plastic tub. Then drop
in the rusted item and walk away.
Remove rust with powerful chemicals...
The old standby rust remover chemicals
contain either phosphoric or
hydrochloric acid to dissolve the rust.
They’re harsh chemicals that give off
some pretty intense fumes, so suit up
with rubber gloves, goggles and a respirator.
Find them in the paint department
at any home center. You’ll also
need an old paintbrush, a waste tub, a
3-in. putty knife and rags.
Apply the chemicals with the paintbrush
and wait the recommended time
for the chemicals to work. Then scrape
off the liquefied rust. You won’t get it
all in a single step—count on multiple
applications to completely remove
heavy rust buildup. Consider a gel formula
when removing rust on vertical
surfaces. It’ll cling better and result in
less runoff.
...or with safer and gentler chemicals
Try one of the newer nontoxic and
acid-free soaking solutions shown here.
I bought this gallon of Evapo-Rust at an
auto parts store. These
chemicals dissolve rust through the
process of “selective chelation.” I don’t
know what that is, but I can tell you it
works if you’re patient.
Start by cleaning off any oil or grease.
Then dunk the rusted part in a tub of
solution. The product says it’ll dissolve
rust in either 30 minutes or overnight.
Based on my experience, you’d
better plan on overnight, because even
this minimally rusted C-clamp took
that long. Keep in mind that this is a
soaking solution—you can’t paint it on
or spray it on. So, if you’ve got a large
object, you’re going to need a lot of
solution, and that’s going to cost a lot
more.
You can buy it by a gallon four-pack for about $44 at Ace
or at
Amazon through our affiliate program.
Acid Magic
I’ve written before about how much I love using Acid Magic for removing rust from sinks, toilets and showers. Well, I obviously have lots of iron in my well water—the latest evidence is that all our ground-level windows had a reddish tint from the sprinklers. I had no idea how to remove it until I thought of Acid Magic again.
I brushed it on with a paintbrush and the rust instantly dissolved and ran down the glass. If you have other mineral deposits in your water, I’m certain it’d take care of them, too.
-Travis Larson, Senior Editor
The conversion method
1 of 3Choose between liquid and spray converter
Rust converter comes in brushable
liquid or aerosol spray.
Spray provides a smoother finish
but doesn't penetrate severe
rust as well as brushable liquid.
2 of 3Apply converter after wire brushing
Pour a small amount of converter into a cup and work it into
the rusty patches with a paintbrush. Then smooth out the
brushstrokes and let it dry.
3 of 3After
When dry, the surface will look rough but rust-free.
Convert it—it’s the easiest method
If you can live with the look of a rough or pockmarked finish,
rust converter can save you a lot of time. It kills the rust, prevents
its spread and dries into a ready-to-paint
primer. Buy it at any home center
or auto parts store. Start by removing
any flaking paint and rusty dust
with a wire brush. Then either
spray on the converter or
apply it with a disposable
paintbrush.
Let it dry for the recommended
time. Even though
the label says you can
paint after it dries into a
primer coat, I recommend
spraying on a real primer.
Then paint. Apply a second
coat of converter if you’re
not going to paint. Don’t
return leftover converter to
the bottle—it will contaminate
the rest. Toss it in the
trash, along with the brush.
Three Ways to Remove Rust
Grind, sand or scour off the rust
Pros: No pockmarks and a smooth finish prior to painting. Complete project in a day. No waiting for chemicals to work.
Cons: Dirty, dusty, hard work. Requires power tools and lots of elbow grease.
Convert the rust
Pros: Easiest way to stop rust and prime in one operation. Less expensive than chemical or mechanical methods for removing rust.
Cons: Leaves a rough or pockmarked finish that’ll show after you paint. May not inhibit rust as long as traditional removal, priming and painting.
Remove rust with chemicals
Pros: Soaking removers can do all the work for you if the item is small enough. Spray removers greatly reduce the grunt work, but they require several applications and some scraping.
Cons: Long wait times for the liquid removers to do their job. Makes a huge mess. Soaking removers are expensive and can be used only on small items. The surface will still be pockmarked after the rust is gone.
Tip: Don’t think you can spray rust-inhibiting paint onto a rusty surface and get good results. The rust will bleed right through the paint and ruin your new paint job. You have to deal with the rust with one of the methods we show here. There’s just no way around it.
Prevent rust: Prime first!
1 of 2Pick your primer
Choose a regular
(nonsandable)
primer if the surface
is completely
smooth. To fill in
scratches, choose
a sandable primer
and lightly sand
when dry. Or, use a
filler primer to fill
in pockmarks.
2 of 2Prepare and prime
Clean the metal before priming. Then apply the primer over the old
paint and the newly sanded metal.
Prime before painting
No matter how you get the rust off, you still have to prime
before painting. If the surface is smooth, simply
spray on a metal primer (light gray for light-colored paints,
black for darker paints). However, if the surface still has
pockmarks, swirls or scratches, use a “sandable” or “filler”
primer to fill in the depressions.
Surface preparation prior to priming is critical, especially
if there’s any old paint left on the item. Clean the surface
with a wax-removing solvent (buy at any auto parts store) and a tack cloth.
Prevent rust: Paint & topcoat
1 of 2Shop for rust-inhibiting paint
Several companies make
rust-inhibiting paint. If you
don't find the color you
like, try the paint department
at an auto parts
store. Spray on a final
topcoat of clear gloss.
2 of 2Apply a clear topcoat
Allow the color coat to dry completely. Then spray on a
clear topcoat to extend the life of the paint.
Pick a high-quality paint
After all the nasty prep work, why risk
another bout of rust by using cheap
paint? Inexpensive paint contains less
pigment, fewer resin binders and no rust
inhibitors. Spend a few extra bucks on
a premium rust-inhibiting paint. It will
contain zinc additives that provide an
extra measure of protection against future
rust.
Brushing usually provides a better
paint bond than spraying, but it leaves
brushstrokes in the finish. However,
spraying is tricky and if you stay in one
spot too long, you can wind up with
paint sag marks in the finish.
Whichever painting method you
choose, seal the newly painted item with
a clear topcoat. That’ll add to the gloss
and dramatically increase the life of the
paint by reducing paint oxidation.
