by Steve Hingtgen, Founder of Vintage Trailer Supply
Can My Trailer Be Polished?
Is Polishing For Me?
How to Polish an Airstream
Maintenance
Re-polishing
Frequently Asked Questions
Airstream shells are made of aluminum. Aluminum reacts with
oxygen in the air to form aluminum oxide, or oxidation. But unlike steel
when it oxidizes to form iron oxide, aluminum doesn’t rust. The
chemical reaction between aluminum and oxygen doesn’t eat away at the
aluminum, it actually builds on it . . .and darkens it.
That’s the chemical part of the story, but not the part that has brought
you to the point of polishing. More likely, this is an emotional
decision. Once you’ve seen a freshly polished Airstream, it’s hard to
look at Airstreams or aluminum the same way again. The mirror finish on
that vintage streamline shape is nothing short of stunning. The rivets
and seams are accented against the mirror panels, and you feel the urge
to run right home and polish your own trailer. It isn’t about the
chemical reaction, it’s about the emotional one.
This article provides a basic description of how to polish a vintage
Airstream. But first, it’s important to know that polishing isn’t for
everyone. And it isn’t the same for every trailer.
Can My Trailer Be Polished?
All Airstreams can be polished to a very nice shine. However, not every
trailer can achieve the eye-popping mirror of a vintage Airstream. As a
general rule, the softer the aluminum alloy (higher aluminum content),
the better the shine.
Airstreams built up to 1982 used a .032”
thick aircraft-grade aluminum alloy with a very thin layer of nearly
pure aluminum electrochemically bonded to both sides. This special type
of aluminum sheet is called
alclad aluminum. The aluminum
alloy underneath the cladding (2024-T3) is strong and is what gives the
trailer skin its strength. The pure aluminum cladding is soft and is
what shines up so well when polished.
While some travel trailer manufacturers used alclad only until the early
1960s, Airstream used alclad panels into the 1980s. Starting in the
middle of the 1982 production run, Airstream changed the type of
aluminum they used on trailers to .040” non-alclad 3004-H18 aluminum.
This alloy is much softer than the 2024-T3, so it needed to be thicker.
However, because it is softer, it can still be polished to a very nice
shine. However, without the pure
aluminum cladding, it won’t achieve quite the same mirror as an older
trailer.
Another important change to Airstream exteriors was the application of a
lacquer coating over the aluminum starting in the 1960s. The
coating–called
plasticoat–was added because the aluminum
skins were oxidizing so quickly that customers were complaining.
Airstream had been applying glass wax to slow down the oxidation, but it
didn’t
last more than 6 or 7 months.
Starting as early as 1958, Airstream dealers started offering an
early version of plasticoat on a handful of trailers as a way to stop
the oxidation. In 1961 it became an official option you could have
applied to your trailer for an extra charge. In 1964 it became standard
on all Airstream trailers.
The formula has changed several times over the years, some
versions lasting longer than others. But eventually they all fail and
start to flake off as the aluminum expands and contracts with the heat
of the day, and the UV rays dry out the coating, making it brittle.
Usually the failure starts on top, like a sunburn. It takes many many
years for the sides to peel.
A previous owner of your trailer may have struggled with this
problem and either had the trailer replasticoated, had the plasticoat
stripped off completely and polished (or tried to polish) the trailer,
or simply let time take its toll and watched as most or all the
plasticoat disappeared.
No matter how old your trailer is, if your trailer has any plasticoat on
it, the coating must be entirely removed from areas you intend to
polish. Directions for determining whether or not your trailer still has
a plasticoat and removing it are detailed later in this article.
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Is Polishing For Me?
Polishing is labor-intensive. The time it takes depends on the size of
the trailer, the amount of oxidation, the efficiency of your technique,
and the number of breaks you need. At a minimum, expect to spend at
least three full weekends on this project. Add a weekend to your
timeline if you have to remove a plasticoat. It is not uncommon for the
project to take twice that much time.
The good news is that once a trailer is polished to a mirror shine, the
second time takes far, far less time. That’s an important thing to know
since you may very well be repolishing every year to keep the shine.
Once the aluminum surface is polished, future polishing will be easier
and the shine will last longer because the aluminum surface becomes
smoother and is further “healed” with every polishing.
To understand the smoothing and healing process, it is important to
understand that aircraft-grade aluminum polishes–like Airbrite or
Nuvite–do not remove oxidation with a chemical process, but rather by an
abrasive process. Aircraft-grade polishes are specifically designed to
be used in steps, somewhat like sandpaper. Each successive step is a
finer polish. The coarser polishes are used on highly oxidized or
slightly corroded surfaces. The finest polishes are used only after
nearly all oxidation has been removed.
The skin of your Airstream is covered with small and microscopic
scratches, pits and other imperfections. By smoothing the surface during
polishing, the surface area is reduced, providing less opportunity for
oxygen to bond with the aluminum to form the aluminum oxide.
In addition, oxidation left on and in a polished surface increases the
breeding of more oxidation, causing the polish job to dull more quickly.
The cleaner the surface of oxidation, the longer the polish job lasts.
So, is polishing for you? This article helps you assess the work
involved. Your ability and willingness to do the work must be weighed
against the value to you. It is undeniable that the pride of ownership
and resale value of a trailer are substantially increased. But since
oxidation doesn’t harm a trailer’s skin, perhaps you will decide you can
live with the unshined look.
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How to Polish an Airstream
The following polishing procedures were developed from our own
product field testing, polish manufacturer lab and field testing, and
feedback we’ve gathered from our customers who have experimented with
various polishing techniques and products over more than six years.
Polishing techniques continue to evolve. Although we can confidently
recommend the following procedures, they are not the only way to get
satisfactory results. You are encouraged to experiment if you have the
time.
Tools, Equipment and Supplies
In practice, a polish’s aggressiveness depends on the polishing
pads or fabric and the tool being used. Therefore, you’ll need two
different power tools to complete all the polishing steps. To do it all,
you’ll need both a variable speed rotary polisher AND a Cyclo dual-head
orbital polisher. There are a number of brands of rotary polishers.
Look for a heavy duty 7” variable speed model capable of operating at
~1500 rpm. The DeWalt DWP849 is highly recommended. Do not use an
orbital car polisher; it isn’t aggressive enough.
Along with two power tools, you’ll need the following pads and other items:
- 7” twisted-wool polishing pads (5+)
- 7” velcro backplate to hold pads
- A “spur” polishing pad cleaner
- Cyclo foam backing pads Cyclo cotton terry bonnets OR several yards of heavy cotton fabric (95% cotton flannel or 100% cotton t-shirt fabrics work well)
- Scaffolding or ladders for safe work on side and top of trailer
- Ladder padding to protect trailer
- Diaper cloth or other soft cotton rags Mineral spirits
- Appropriate grades of Airbrite, Nuvite or other aircraft polishes
Step 1: Remove parts that might be damaged during polishing
Lenses on porch, tail or marker lights should be removed. Any
other plastic or painted parts that might be damaged during polishing
should be protected by taping off or removing them. Remove the red WBCCI
numbers and VAC decals and buy new ones to replace them.
Glass windows are safe, but plastic vent covers may become discolored or
damaged. Door and window gaskets are safe from polishing, but should be
protected during plasticoat removal (if applicable).
Step 2: Clean the trailer
Oils and waxes will interfere with
effective polishing. Use a soft wool
car wash glove and warm soapy water
(dishwashing liquid is fine in this case)
to thoroughly wash your trailer. If you
see any bird droppings, tar or pine sap
anywhere on the trailer, take mineral
spirits or more aggressive solvents and
remove those deposits. With a rigid
plastic or wooden tool, pick any dried
loose caulk out of the seams.
When you are finished cleaning
and prepping, be absolutely satisfied that
the surface is clean. Any dirt, sand or grit
left on the trailer when you start polishing
will cause severely damaging scratches
in the trailer skin. Note: do not use any
cleaning product containing ammonia.
Ammonia reacts with aluminum.
Step 3: Remove plasticoat
All remnants of a plasticoat must
be removed before a trailer can be
polished.
If you aren’t sure whether your
trailer has a plasticoat, there are several
ways to find out. First, take a look at
your trailer from a distance. Does it look
like it has a sunburn up top? Are there
distinct splotches of darker oxidized
aluminum and then the rest of the trailer
is looking fairly good? If so, you have a
plasticoat and the top has failed. This
is natural since the top of the trailer gets
a lot more UV and heat than the rest of
the shell.
One way to check conclusively
to see which areas have a plasticoat
and which do not is to get a clean white
cotton cloth and a tube of white (not gel) toothpaste. Pick a few inconspicuous
areas of the trailer to polish with the
toothpaste, the rag and your finger. Do
just a small one inch patch Are you
getting black aluminum oxide on the rag?
Or is it just dirt? If you have plasticoat
in that area, you won’t get any oxide
because the plasticoat is protecting the
aluminum from your polishing efforts.
If you need to remove the
plasticoat, you will need to use either
paint stripper or lacquer stripper. This
is a process much like stripping a finish
from wooden furniture
except you
should never use any abrasives on
your trailer (other than the polish, itself).
That means: no steel wool, no green
plastic scrub pads, and of course, no
sandpaper.
We recommend using an
environmentally safe stripper designed
for removing paint from metal. PPG
Aerospace PR-5044 is a popular choice
and works extremely well. It’s safe to
work with and can be hosed off when
finished without killing the grass or
harming the groundwater. Usually one
or two gallons is enough to do the job,
but test a small area first.
Before applying the stripper,
on a warm day park your trailer in the
shade. Brush the stripper on to one or
two panels of your trailer. Follow the
directions on the container, requiring it to
sit for a period of time while it dissolves
the plasticoat. If you need to work it
around to loosen the plasticoat before
hosing off, use the tips of a large house
painting brush. They are soft and won’t
scratch. You can also use a plastic putty
knife, spatula or scraper. You may have
to reapply the stripper if some coating
remains. When your entire trailer has
been stripped, clean the trailer well
according to the instructions in Step 2.
Step 4: Oxidation Removal
If your trailer is significantly oxidized
(as all trailers are if they have not been
polished in several years), begin here.
For this step, you will be using a coarse
polish like Airbrite No.2 or Nuvite Grade
F7 and your 7” rotary polisher with a new
or clean wool compounding pad.
Place one finger across the
top surface of the polish, just wetting
your finger with polish (do not dip out
a quantity of polish) and put a wet “fingerprint” of about half a finger length
every 3” or so over an area to be polished
approximately 3 to 4 square feet. Work
fairly quickly so that the polish does not
dry out.
Place the wool compounding
pad onto the “fingerprinted” area, and
smear the polish around a little before
turning on the polisher. Tilt the pad up
slightly so that the pad is not laying flat
as it spins, but rather so that only one
side of the pad is touching the surface.
The polisher should run slowly–ideally
1200 to 1500 rpm. As it spins, move the
polisher over the surface at a speed of
about a foot every one to two seconds.
Light but firm pressure is all that is
needed. (If it were a horizontal surface,
you would want to use about the weight
of the buffer or very slightly more.)
Lightly scratched areas may
require working back and forth, then
up and down, then diagonally over the
scratched area several times to blend
the scratches. Do not stop moving
the pad and “bear down” on one area
to blend the scratch. It can cause the
surface to get too hot and scorch.
As you work back and forth,
black residue will form over the buffing
area. Continue moving the buffer back
and forth, up and down, across the
surface. After about 30 to 45 seconds,
the black residue will begin to lighten
and disappear if you have the correct
amount of polish.
Continue moving over the area
until the black residue is gone and the
clean aluminum surface shows. Black
residue may remain around the edges of
your buffed area, but that will be cleared
as you move to the next adjoining area
to be buffed. If further work is needed
to clear the cloudiness, or if scratches
remain prominent, repeat the above
process.
Repeat the above steps on the
next adjoining area, and so on, until the
entire panel, and then the whole trailer,
is complete.
As you go along, the wool
compounding pad will mat up. The oxide
and polish will make it look shiny. When
this happens, fluff the pile of the pad by
“spurring” it with a buffing spur. Spurring
loosens the matted fibers and lets you
use the pad longer before changing to
a clean pad.
At the end of the oxidation
removal step, you will be left with bright
aluminum and very little oxidation, but
there will be very noticeable swirl marks
from the pad and the relatively coarse
polish being used. They will be removed
in the next step.
Step 5: Polishing
After Step 4, or if you trailer has been
polished within the past three or four
years, you may be able to start with
this step.
Using a medium abrasive polish
like Airbrite No.4 or Nuvite Grade C
and your 7” polisher with clean or new
compounding pads, repeat the process
described in Step 4 over the entire
trailer.
After polishing the entire trailer,
use a clean cotton terry towel, diaper
cloth or similar fabric to hand wipe the
entire trailer to remove any surface
polish. Look for accumulations of
residue around rivet heads and along
panel lines. Mineral spirits may be
used to dissolve and remove difficult
deposits.
At the end of this polishing step,
all visible oxidation will be gone and
your trailer will be beautifully polished.
You may decide that you don’t want to
continue to Step 6. Certainly, that is an
option, but keep in mind that the more
smooth the finish, the longer your polish
job will last.
Alternative Steps 4 and 5:
Although somewhat more difficult,
some people use a 1/2” drill with a
side handle instead of the 7” rotary
polisher. A backing plate adapter
is available for drills.
Step 6: The Mirror Finish
For this step you will be switching to the
Cyclo dual-head orbital polisher. You will
be using a “no-cut” polish like Airbrite
No.6 or Nuvite S.
There are two ways to use
the Cyclo. One is to apply cotton terry
bonnets to the Cyclo heads (over foam
pads) and polish just like you would
a car. This leaves mild swirl marks.
They’ll be much smaller and lighter
than if you stopped with Step 5, but they
will be noticeable in direct sunlight. The alternative method is more awkward,
but completely eliminates the swirl
marks. With this method, you are
using the Cyclo for its random, vibrating
movement, and not for its spinning.
To eliminate the swirling, you will
cover the heads with 95%+ sweatshirt
fabric, soft 100% cotton flannel or heavy
100% cotton T-shirt fabric. Wrap a
section of the fabric over the face of the
foam polisher pads, being sure to leave
motor vent openings unobstructed. The
size of the fabric doesn’t have to be
exact, but a piece approximately 30” x
40” works well.
Similar to the method in Steps
4 and 5, place one finger across the
top surface of the jar of polish, and put
a wet fingerprint about half a finger
length every 6” or so over an area to be
polished approximately 3 to 4 square
feet. (Note that this is less polish than
used in previous steps.)
Pull the fabric tight over the
face of the polisher and hold it with your
hand as you grip the polisher handholds.
You’ll be bunching it up and even twisting
it as you work to grip it all with one hand.
Some people use a ratcheting plastic
cable clamp to help hold it. The fabric
needs to allow the heads to spin and
vibrate underneath the fabric without
grabbing it.
Smear the face of the polisher
around the area to be polished before
turning on the polisher, then turn it on
and move the polisher over the area
at the rate of about one foot of travel
every three seconds. Use only light
pressure.
Move the polisher back and
forth and up and down. Work the areas
around raised rivets and panel lines
more, if necessary. Black residue will
appear as before.
After 30 to 45 seconds, the
black residue will begin to disappear as you continue buffing over the area,
and the bright, mirror shine will begin to
appear. Work back over rivets and panel
lines to clean the residue from these
areas as well as possible.
When the area is clean of
surface polish, stop the polisher. Now
adjust the placement of the fabric on the
Cyclo so that a clean spot of the fabric is
now over the heads. Do a final buff over
the whole area, continuing the cleaning
and brightening of the finish and picking
up any light residue caught around rivets
and panel lines.
Finally, finish with a clean
microfiber, flannel or diaper cloth material
by hand, lightly cleaning close in around
rivet heads and with folded material
to get back against the edges of the
panel lines. Be careful not to drag any
deposited polish onto the clean, clear,
polished panel image.
Alternative Step 6:
If you are struggling to work with
the cotton cloth wrap on the Cyclo,
you don’t have to do it. If you don’t
mind mild swirl marks, simply use
cotton terry pads on the Cyclo. It’s
much easier, and the minor swirl
marks will fade with time.
Step 7: Sealant
Unless you intend to pay a professional
to immediately plasticoat your trailer,
you’ll need to prepare yourself for
reoxidation in the months and years
ahead. The better your polish job,
the slower the reoxidation. But no
matter how well you did, your trailer will
reoxidize over time.
One way to slow the reoxidation
is to apply a sealant like the kinds that
are used after hand washing a car. In
the old days, Airstream used glass wax.
Glass was is no longer available in the
formulation from decades ago. Some
people still use car wax, while others
use a non-wax polymer sealant made
for cars or boats.
The application of any sealant
is controversial. Those who oppose it
say it does little to retard the reoxidation
and it slightly dulls the mirror shine.
In addition, it will need to be removed
before repolishing.
If you do apply a sealant, you
can expect it to retard reoxidation for
roughly an additional six months.
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Maintenance
Between polishings, keep your Airstream
clean. Immediately remove any road
tar, bird droppings, insects or pine sap
using a vinegar-based glass cleaner or
soap designed for washing cars. As previously stated, do not use any cleaner
with ammonia as an ingredient.
For stubborn stuck-on messes,
use mineral spirits or other solvents.
Keep in mind that solvents and detergent
can strip protective waxes and polymers
from the skin of your trailer.
Re-Polishing
The rate of reoxidation varies somewhat
depending on how healed the aluminum
is, and environmental conditions like
sunlight, pollution and humidity.
Normally, you will need to
repolish once each year to keep your
trailer looking great. Fortunately, the
annual touch-up can go fairly quickly
since it may be possible to do only Steps
2 and 6. In some cases, Step 5 may be
necessary.
Frequently Asked Questions
Q. What brand polish is best?
A. We’re not snobs about polish. We
sell aircraft-quality Airbrite and Nuvite
abrasive products because they have
been thoroughly tested and proven
safe for aluminum. Other high quality
polishes may work well too.
Q. When is the best time to reseal
seams?
A. A good time to apply Trempro 635
or another sealant to seams between
panels and around vents and windows is
between Step 4 and Step 5. If you wait
until you are finished polishing, you’ll
make a mess of your new mirror finish.
Q. Should I worry about polishing
through the cladding?
A. As long as you follow the procedures
described, you will not damage the
cladding. Airline maintenance crews
polish aircraft dozens and even hundreds
of times without problems.
Q. Can I sit on top of my trailer when
I polish?
A. Yes, you can even stand on it. The
trick is to keep your weight on the ribs.
The rivet lines follow the ribs on the roof.
Please be careful up there.
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