Aluminium corrosion
Aluminium
alloys are alloys in which aluminium is the predominant metal. The highly
reactive nature of aluminium metal is normally masked by the protective oxide
film (White rust), which readily forms in moist air and renders the metal
kinetically stable. Galvanic corrosion can occur when an aluminium alloy is
placed in electrical contact with other metals with a more negative corrosion
potential than aluminium.
·
Thoroughly clean the
affected surfaces of all soil and grease residues with a d-limonene (citrus)
based solvent cleaner (P21S® Total Auto Wash) prior to processing.
·
Brush it down with a wire
brush to get rid of all the powder.
·
Clean the surface with PrepSol and then sand any scratched or
damaged areas with Norton 3X Sandpaper (p-graded aluminium oxide grain,) 60, 80
or 100 grit sand paper, sand wet or dry with a rubber sanding block.
·
Use a tack rag and wipe the area, using a light pressure
·
Then treat with etch primer,
maybe two or more coats.
·
Follow with ordinary primer and top coat.
Be
cognizant that if aluminium becomes badly corroded they require an acid dip
bath and the polishing
Repairing a Damaged Polished Aluminium Lip
Dremel 3000 Variable Speed
Rotary Tool, plus accessories- kit #
697-- #952 CONE shaped Aluminum Oxide Grinding Stone and - #413 Sanding Discs
240 GRIT
1.
Using the Dremel on its lowest setting with the (#952) Cone
shaped stone and grind down the burrs to as near smooth as you can.
2.
Change attachments to the (#413) Sanding discs and smooth the
surfaces
3.
Start by using 800 grit finishing
paper and then work through 1000, 1500 and finally 2500.
4.
Using #0000 synthetic steel
wool to bring back the shine
5.
Finally finish polishing with OPT Optimum Metal Polish
6.
Use a clear polymer
protection (OPT Optimum Opti-Coat)
Repairing Scratched or Curbed Wheels
Damage to your wheels can
come from: curb damage, wheel weight scratches, low acid spray, lug nut impact
wrench, auto accident, and road salt, which leads to oxidation. These blemishes
can ruin the appearance of your car; refurbishment can help retain its value.
Replacement costs for an alloy
wheel can cost hundreds of dollars + 3-4 days without the vehicle) but the
restoration of your scuffed alloys and scraped wheel rims makes your whole car
look pristine again
•
Wheel Collision Center –http//:www.wheelcollision.com/
•
Wheels America 8004-Fix-Rim – Powder coat Finish - http://www.wheelsamerica.com
•
Wheel Repair UK - http://www.thewheelspecialist.co.uk/...ce_details.php.
Be cognizant that serious
damage to a wheel may affect the vehicle’s alignment and subsequent steering,
always check for structural damage (i.e. surface cracks) or deformed rims,
which should always be replaced. Shop cosmetic / appearance wheel repair-
approx. $100 –150 per wheel, usually 48 hours (dependent upon geographical
area)
These procedures are for aesthetic and slight
damage only
Taking the wheel(s) off
makes it far easier to work on and much more comfortable than stooping down
Small Scuff Repairs (Alloy Wheels)
Time: 4 – 6 hours per wheel for a
complete wheel-off repair and repaint renovation. Materials-2-17 oz. Wurth
Clean-Solve, 2-10.2 oz. 1Z Einszett Spray Paint Primer "Haft-Grund",
2-13.5 oz. 1Z Einszett Silver ( will match Titanium Silver) Wheel Spray Paint,
2- 13.5 oz. Wurth High Gloss Clear Lacquer, 14 oz. Bondo® (approx. total 90 USD)
See also Personal Protective Equipment
(PPE)
•
Remove the damaged wheel
from vehicle.
•
Deflate the tyre by
unscrewing cap and pushing in valve, once the tyre is flat push the tyre wall
down (gently) by standing on it, and then
tuck masking tape underneath the wheel rim, working your way around
slowly
•
Dremel Tool (with variable speed) accessory kit # 697-06 and #952 CONE
shaped Aluminum Oxide Grinding Stone.
Use on its lowest speed (5000 RPM) and grind down the burrs, they can
then be made perfectly smooth by using finishing paper and a sanding block
•
Molecular Tech Coatings
Inc., EFS-2500 aircraft paint stripper is environment
friendly. It can get easily decomposed and is also non-toxic as well. In terms
of chemical composition, there is no methylene chloride, no carbonic acid, and
no formic acid present in the paint stripper. Hence, it is perfectly safe to
use.
•
Clean the damaged area with
PrepSol and then sand the scratched or damaged area with Norton 3X Sandpaper
(p-graded aluminium oxide grain) 60, 80 or 100 grit sand paper, sand wet or dry
with a rubber sanding block.
•
Use a tack rag and wipe the
area, using a light pressure
•
Only use filler (3M™
Acryl-Green Spot Putty) if it’s essential to the e
repair, if used incorrectly it will flake and significantly reduce the
effective life-span of the repair. Fill any minor indentations with 3M™
Acryl-Green Spot Putty, allowing approx.
30 minutes before you shape / sand
•
Sand the wheels until you've
removed the scratches, `kerbing' marks and/or smoothed the filler flush with
the wheel surface.
•
Powder coat is harder to
sand than paint, so be prepared for prep sanding to take longer
•
Continue the sanding process
using finer and finer grades of UniGrit paper, 220 or 320 grit and finally with
500-grit paper.
•
For small hard to reach
places use a Dremel Tool and a suitable sanding bit
Note:
To repair damaged powder coatings requires that you completely strip the
coating and re-coat, and then bake the finish in ovens. Without heat powder
coatings will not cure and the touch-up will simply be a patch but never as
good as the original coating.
Removing Surface Scratches:
The standard OEM finish for wheels is a
clear coated aluminum; small scratches and blemishes can be polished and the surface finish can be renovated ‘as new’ The clear coat on
wheel surfaces is usually thicker than that of the main paint surfaces, but
check with a PTG before you start to polish.
Use a 3-inch foam pad and a
polishing compound (polish selected is dependent upon the extent of damage) it
may take a few passes; follow with a soft foam pad and a finishing polish.
Felt Polishing Cones - if
you're faced with polishing tight places, try some versatile polishing wheels.
They come in various sizes and shapes to complete just about every polishing
project-wheel, intake manifolds. Fitted to an electric drill they will quickly
restore an ‘as-new’ OEM finish.
Brut Spot Shot - sand blaster; a complete
hand-held recovery blaster system for a fraction of the cost of an ordinary,
vacuum blaster, ideal for small jobs in enclosed areas; grit is captured,
forced back into the filter bag, and recycled. It’s virtually dust-free; no
mess, no hassle, no need to work outside. Blasts a small pitted or rusted area
right down to bare metal in seconds! Comes with the revolutionary Pit Grit, a
high-tech blend of several space age abrasives when rust is the problem,
Pit-Grit is the solution! Weighs 6 lbs - UPS shippable
Surface Preparation
·
Ensure wheels and rotors are
cool before applying cold water as this may cause them to warp.
·
Hose off as much initial
grime as you can.
·
Rinse up into the wheel well
to wash away road kill, mud and other debris.
·
Use detailing clay and
lubrication to remove any embedded contaminants
·
Use a d-limonene (citrus)
based cleaner to remove any road tar or oil. Apply P21S® Total Auto Wash to wheel surfaces and let soak in, agitate
with a long-handled boar’s haired brush before rinsing
·
Spray P21S® Wheel Cleaner (Gel or
Liquid) this cleaner is 100% acid-free and will not damage any type of wheel
finish. (Gel for badly soiled and regular for normal soil) onto wheel rims and let
soak in (for badly soiled surfaces us P21S®-Red (422) or Sonax Wheel Cleaner both are formulated with
neutralised acid salt
·
Used the P21S® Polishing Soap on the
clean wheel to polish the lips, inner wheel, and face of the wheel. (agitate
lightly on the clear coated parts)
·
Before finally removing
cleaner, agitate with a soft brush and then rinse off
Refinishing
Be cognizant that its common practice on some alloy
wheels (among others BMW and Audi use this method (i.e. a light coat of silver
over black base paint) to obtain a two-tone shadow chrome finish) In some
instances using a harsh acid or alkaline will remove the thin layer of silver
exposing the black basecoat and then the primer coat, which gives a similar
appearance to acidic surface damage.
See also Personal Protective Equipment (PPE)
Be cognizant that most European
OEM wheels are powder coated, so paint won’t be an exact match. Place the can in a bucket of hot water for
ten minutes prior to spraying. This lowers its viscosity and it will spread
more evenly without ‘runs’, it also
raises the temperature of the air inside, which in turn increasing the pressure, enabling a much
better spray ‘pattern’ resulting in a better finish.
•
Remove the damaged wheel
from vehicle.
•
Deflate the tyre by unscrewing
cap and pushing in valve, once the tyre is flat push the tyre wall down
(gently) by standing on it, and then
tuck masking tape underneath the wheel rim, working your way around
slowly
•
Molecular Tech Coatings
Inc., EFS-2500 aircraft paint stripper is environment
friendly. It can get easily decomposed and is also non-toxic as well. In terms
of chemical composition, there is no methylene chloride, no carbonic acid, and
no formic acid present in the paint stripper. Hence, it is perfectly safe to
use.
•
Clean the damaged area with
PrepSol and then sand the scratched or damaged area with Norton 3X Sandpaper
(p-graded aluminium oxide grain) 60, 80 and finishing with 100 grit sand paper,
sand wet or dry with a rubber sanding block.
•
Tack clothes helps control dust by picking it up off the surface
and also helps eliminate static that attracts dust. Use a tack rag and wipe the area, using a light pressure
•
Only use filler (Bondo Lightweight Filler 264 and Red Cream Hardener) if it’s
essential to the repair, if used incorrectly it will flake and significantly
reduce the effective life-span of the repair. Fill any minor indentations with
Bondo, allowing approx. 30 minutes before you shape / sand
•
Sand the wheels until you've
removed the scratches, `kerbing' marks and/or smoothed the Bondo filler flush
with the wheel surface.
•
Continue the sanding process
using finer and finer grades of UniGrit paper, 220 or 320 grit and finally with
500-grit paper.
•
For small hard to reach
places use a Dremel Tool and a suitable sanding bit
Note- If the above cleaning method don’t
finish to wheels to your liking have them bead blasted
Repainting (cast aluminium) Wheel Surface
See also Personal Protective Equipment (PPE)
OEM Factory wheel finishes are either an acrylic polymer or a
polyester powder coat process, which is the most durable finish you can use.
The following Würth products will result
in a durable re-finished repaint colour match
·
Molecular Tech Coatings
Inc., EFS-2500 aircraft paint stripper is environment
friendly. It can get easily decomposed and is also non-toxic as well. In terms
of chemical composition, there is no methylene chloride, no carbonic acid, and
no formic acid present in the paint stripper. Hence, it is perfectly safe to
use.
·
Prepare the surface by
removing all sandpaper residues with a tack rag, wash surface and then dry
thoroughly.
·
Use 3M Painters Masking Tape between
the tyre and the wheel rim (or use Vaseline to mask the tyre from paint overspray)
·
Wipe-down the wheels with DuPont Prep Sol and allow to air dry.
·
Apply a thin coat of 1z 'Haft-Grund' Self-etching Primer to stabilize and provide an etched surface.
·
Use at temperatures between
70 – 90.oF (.Do not use this paint in damp conditions)
·
Shake the can well for at
least a full minute
·
Push the spray nozzle as you
sweep across and release at the end.
·
Spray on, spray off. Spray on, spray off; apply as a very fine /
thin coat.
·
Paint the wheels with two
thin coats of silver alloy paint (Wurth German Alloy Silver Wheel) to ensure
complete coverage
·
Apply your first coat of
clear then allow it to dry to the touch before applying your next coats. This
‘tack coat will help stop the paint from sliding into ‘run’ formation.
·
Allow air-drying; 1-2 hours
on final coat and then lightly sand finish, then leave to cure overnight.
·
Finish with a clear lacquer
paint (Würth European Blend Lacquers) apply two or three thin coats of clear with about 20-30
minutes of drying time between coats to seal the silver metallic paint and add
depth and gloss
·
A allow clear coat to
air-dry and then cure for 4-6 ours
·
Apply a sealant for
protection
·
If your axle/ wheel centres
(hats) are cast iron, you may want to consider painting the hat area with some
hi-temp black engine paint
Product
details
Audi, BMW, Mercedes-Benz,
Porsche, VW, and most other European OEMs use a cast aluminium alloy
wheels. They're usually painted silver and have a clear coated finish or have a
silver powder coated finish
1.
1z 'Haft-Grund' Self-etching Primer - bare
metal (steel or aluminium) wheels should be primed first with a self' -etching
primer and is lead and cadmium-free Applied under a topcoat of urethane paint
provides a secondary method of protecting the steel from corrosion. This primer
bonds to bare metal and forms a base suitable for synthetic resin, acrylic
lacquer and nitro combination paints. A single can will prime two wheels
Warning - Do
not use this primer on painted or clear-coated wheels where you are touching-up
scuffs and scrapes. A self-etching Primer is for use only on wheels that have
been taken down to bare metal.
2.
Würth German Alloy Silver Wheel Paint (Aerosol) can be used
as a spot touch-up or whole wheel repaints, one can is enough to coat two
complete wheels. This paint is unusually user-friendly, it’s a fast-drying
lacquer that matches the standard wheel paint or powder coated finish used by
Porsche, BMW, Mercedes, VW, Audi and most other European OEMs. One aerosol
restores two complete wheels. to match the OEM gloss of new vehicles
3.
Würth European
Blend Lacquers (Aerosol) - used for all German (silver) painted wheels, to
match the OEM gloss of new vehicles. This paint is unusually user-friendly,
it’s a fast-drying lacquer that matches the standard allow wheel paint use by
Porsche, BMW, Mercedes, VW, Audi and most other European OEMs. Wurth German
Alloy Silver Wheel Lacquer can be effectively used for spot repairs or full
wheel restoration. One can is enough to coat two complete wheels. For the best
results, use at temperatures between 70 and 90.0F
Prevention is better than cure
Protect Your Alloy Wheels
from Kerb Damage - RimPro-Tec - http://www.rimpro-tec.co.nz/kit-accessories.html
Brembo Brake Callipers
Brake Calliper Renovation
A way to spice up the look
and at the same time protects the callipers from corrosion.
The Calliper Paint System
(G2- Manufacturing, Inc. Colorado Springs) features aircraft quality paint,
available in six different high gloss colours, Red, Yellow, Blue, Silver,
Black, & Purple.
The brush-applied paint is heat resistant up to 932.OF;
this paint won't start running into your brake pads, it also seals and protects
against corrosion; it also dries much harder than any rattle-can product
Brake dust and dirt will not
adhere to the calliper surface since adding the paint. The kit includes
everything you'll need to get the job done, besides paint you'll also get
reactor (special bonding agent), high tech calliper cleaner, mixing sticks, and
a brush. Do not attempt to paint the rotor contact surface - http://www.g2usa.com/product/G2.html
See also Personal Protective Equipment (PPE)
Surface Preparation
•
Remove the brake callipers from vehicle.
•
Molecular Tech Coatings Inc., EFS-2500
aircraft paint stripper is environment friendly. It can get easily decomposed
and is also non-toxic as well. In terms of chemical composition, there is no
methylene chloride, no carbonic acid, and no formic acid present in the paint
stripper. Hence, it is perfectly safe to use.
•
Thoroughly clean with PrepSol and
then use either a 3M
Scotch-Brite Red (07447) scuffing pad or sand with Norton 3X Sandpaper (p-graded aluminium oxide grain) 60, 80 or
100 grit sand paper, sand wet or dry with a rubber sanding block.
•
Use a tack rag and wipe the area, using a light pressure
•
Continue the sanding process using finer and finer grades of UniGrit
finishing paper, 220 or 320 grit and finally with 500-grit paper.
•
For small hard to reach places use a Dremel
Tool and a suitable sanding bit
•
Finally use a tack rag and
then wipe the area, using isopropyl alcohol (IPA)
Refinishing
·
Prepare the surface by removing all sandpaper residues with a
tack rag, wash surface and then dry thoroughly. .
·
Wipe-down the wheels with DuPont Prep Sol and
allow to air dry.
·
Apply a thin coat of self-etching primer to stabilize and
provide an etched surface.
·
Use at temperatures between 70 – 90.oF (.Do not use
this paint in damp conditions)
·
Shake the can well for at least a full minute
·
Push the spray nozzle as you sweep across and release at the
end.
·
Spray on, spray off.
Spray on, spray off; apply as a very fine / thin coat.
·
Paint the wheels with two
thin coats of high-temperature paint to
ensure complete coverage
·
Apply your first coat of paint
and then allow it to ‘dry to the touch’, before applying your next coats. This
‘tack coat will help stop the paint from sliding into a ‘run’ formation (orange
peel).
·
Allow air-drying; 1-2 hours on final coat and then lightly sand
finish, then leave to cure overnight.
·
Finish with a clear lacquer paint, apply two or three thin coats of clear with
about 20-30 minutes of drying time between coats to seal the silver metallic
paint and add depth and gloss
·
A allow clear coat to air-dry and then cure for 4-6 hours
Notes:
1.
Cover
any lettering that you don’t want painted with a thin coat of Vaseline
2.
Do
not attempt to paint the rotor contact surface
I would like to think that
these articles become an asset to anyone who is new to detailing and to
professionals alike, as well as industry experts who seek to advance their
knowledge.
I hope the
above article was informative. By having some understanding of the ‘What’ and
‘Why’ as well as the ‘How’ along with a little science to help you understand
how the chemicals we use react, you can achieve the results you desire.
I would appreciate it if you would share
this article as it helps other detailers further their knowledge.
Questions and/ or constructive comments
are always appreciated.
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