Dent Pulling - Your One Stop Shop

Dent Pulling
Aluminium Stud / Dent pulling system
How to dent pull aluminium ?.
AL8
Aluminium Repair System
The Al8 is a capacitor discharge stud
welding system.
Digitally Controlled for precise weld
settings.
The unit is compact and easy to use .
Traditional steel dent pulling equipment
CANNOT be used to repair aluminium .
The digital display gives accurate adjustment of discharge voltages .
Fast tip ignition with its discharge capacity
reduces the welding process to reduce distorsion and so reduce panel damage.
It can also be used for the stud welding of
copper and galvanised steel.
Technical Data
Model
Inpu Voltage
Input power
Fuse
Capacity
Stud weld range
Max speed
Dimensions
Gross weight
AL8
230V 1PH
0.4Kw
16Amp
66000 Uf
3mm-8mm
20 per min
L540xW400xH970
30Kg
Basic welding Ltd : Tel 0161 273 8150
Aluminium Features
Aluminium has many features and characteristics .
It is lightweight and has fast heat dissipation /corrosion
resistance. Good elasticity and excellent shock
charateristics.
It is increasingly being used in the modern motor vehicle .
Due to its lower melting point and quick heat dissipation
aluminium is requirred to be repaired by special tools and
techniques.
Conditions for repair
Secial training is required .
The work area must be explosion proof with a suitable dust
arrest system.
Aluminium dust is also harmfull when inhaled so suitable
protection equipment is also necessary.
Its also highly inflamable in dust particle concentrations so
use must be in a well ventilated area .
Aluminium tools must be kept separate from tools used on
steel to reduce Galvanic Corrosion .
Procedures to repair
Aluminum is unlike steel in that it doesn’t have a “memory” or “desire” to
return to its original shape once it’s damaged. It will want to remain in its
damaged state, and you’ll need to apply different techniques to assist it in
returning to its original state.
Aluminum also gets harder or stiffer when it’s damaged and again when it’s
straightened. This is called “work hardening” and is a definite part of the
understanding process.
Cosmetic exterior panels made from aluminum are generally made from
heat-treated aluminum.
Heat-treated aluminum can range in hardness from a T0 (which is very soft
and malleable) to T6 (so hard that when you attempt to bend it, it’ll break).
Many outer aluminum body panels are temper T4, which is very strong and
dent resistant.
at the point of a laser dot emitted from a thermometer). I have all three
methods and prefer the non-contact thermometer for speed and utility.
Basic welding Ltd : Tel 0161 273 8150
The Process
The Process
Step 1: Assess the damage and develop a repair plan. Gather
all tools and lay them out in repair sequence. Our dent is
softball size with a deeper center that will require stud
welding.
Step 2: Apply heat. Notice the size of the dent is reducing
because the heat is relieving stress that’s locking the dent into
position. Aluminum dent repair should always be heated. The
heat range is between 400 and 570 degrees F. Aluminum loses
its temper once you exceed 570 degrees F and becomes
permanently soft. It will melt and fall through at 1,174
degrees F.
Step 3: Notice the size of the dent as you continue to bring the
dented metal up to the heat repair range. Because aluminum is
such a good conductor of heat, it’ll warm up much faster than
steel. Back off. Be gentle. Try not to burn the paint.
Step 4: Monitor your heat carefully during the heating process
to avoid exceeding the upper range. Several methods are available for monitoring heat: heat crayons (two will be needed, one
at 400 degrees F and another at 550 degrees F), a thermocouple (a wand that transmits digital readouts to a handheld calculator) . any of these two methods is acceptable .
Temparature
A word about non-contact thermometers: They’re sensitive
to shiny surfaces because of how the surface is read by the
thermometer. A painted surface will give an accurate reading, while a bare sanded surface will not. This is important!
The higher the temperature, the bigger the discrepancy
between the painted surface and the shiny bare surface.
The difference can exceed 100 degrees F at the high range.
Solution: Don’t point the non-contact thermometer at bare aluminum.
If necessary, apply high heat black (barbeque paint works) to the repair area prior to heat. In the stud welding process, a black soot forms
around the base of the stud that provides a suitable surface to use. You
may also choose to reduce the area you grind paint from to allow for
taking heat readings from nearby painted areas.
Step 5: Take your heat close to the upper range for better results. While
aluminum heats up quickly, it dissipates heat rapidly so the closer to the
higher limit you are, the more time the metal has to relax and return to
its original contour.
Step 6: Allow to cool. If heat transfer is an issue, you can rapid cool
with compressed air (air blower) or wet rag (messy). Be aware that any
adhesive areas in the heat zone will have to be re-bonded at the
conclusion of the repair, as well as applying corrosion protection from
burned inner surfaces. Note the dented area in the photo has been
reduced to a small deep dent by just heat stress relieving.
Step 7: Sand/grind paint from repair
area using 80-grit disc in grind mode.
Basic welding Ltd : Tel 0161 273 8150
The Clean up
Step 8: Vacuum, don’t blow. Cross
contamination and galvanic corrosion are
serious considerations when working with
aluminum.
Dissimilar metals (steel and aluminum) in
contact with one another in the presence
of an electrolyte (moisture) cause galvanic
corrosion.
It’s very important to make sure you
vacuum up your filings, grindings and dust and don’t blow them
around the shop, where they can land on cars of a dissimilar
metal. Use fresh sanding abrasives to prevent cross
contamination. Vacuum all your tools and wipe them down with a
damp rag to remove all traces of metals.
Some manufacturers recommend separate tool sets marked
“Aluminum Only.”
Step 9: Clean the sanded area, and you’re ready for studs.
The studs as you can see have a little
“nipple” on them , this is what shorts
and creates the contact arc to enable it to weld to the aluminium .
Once this tip has blown the stud can no
longer be used .
These studs are a once only use stud.
Stud welding Setup
Step 10: Before using the Aluminium strud welder test the setting on an
old piece of aluminium to ensure correct settings .
This is important to prevent “blow through.” .
Start with a lower setting and test stud for pulling strength.
The unit comes with two earths it is advisable to use both if you are doing
a large area as this will ensure correct earthing.
If you are only doing a small area then one earth is sufficient.
Ensure the correct holder fits the size
of the stud to be applied .
Fit into the gun and ensure
that the gap is set correctly.
When the gun is pushed onto
the metal the prongs on the
outer nozzle of the gun
MUST be in contact with the
metal securely.
This is how the correct gap
needs to be set. So that his
can occur.
If there is not a good contact
you could blow the metal surface
Contact Prongs
Basic welding Ltd : Tel 0161 273 8150
Apply the Studs
Step 11: Once the machine is
properly set
up, apply the studs to the area .
Step 12: Thread on pulling loops to
threaded
studs to allow for pull. Note the soot
buildup
around the base of stud. This will
provide a
suitable measuring surface for a
non-contact
thermometer, or you may apply
high-heat paint in a nearby location.
Remove the dent
Step 13: Heat the area of the dent carefully to the repair range of
400 to 570 degrees F. Monitor the heat accurately to avoid
annealing.
Step 14: When the desired heat has
been reached, apply the leverage
bar and remove the dents while the
panel is hot.
Move quickly because
aluminum cools quickly.
Step 15: Remove the threaded studs
with side cutters. Don’t try to twist
off, or you may tear a hole in the
panel.
Basic welding Ltd : Tel 0161 273 8150
Dress the area
If you are going to DOLLY the area a
Wood and soft face tools are ideal for
aluminium to reduce stretching.
Also the OFF dolly method is recommended.
Aluminium is susceptible to stretching and to overheating so always observe how much work is done to a cold metal to reduce
risk of cracking.
Step 16: Grind down the
remainder
of the stud to the surface. Use
80 grit. Do Not try to pull or
bend off as shown as this can
tear the metal.
Step 17:
Dress off the area to reveal
highs and lows.
Use the file nor sander at
a 3-degree angle and not
straight back and forth to avoid
file marks.
Step 18: Grind the area with an
80-grit disc and check for highs
and lows
Degrease and clean the area ready
for painting or filler .
REMEMBER .
Use ONLY tools designed or intended for aluminium .
Do not cross contaminate
You can use a localising paste to limit the area
to be heated.
Aluminium when heated heats up the whole
of the panel you can use this to just heat up
the area you want to remove the dent from
Finally ; TAKE YOUR TIME.
We can provide in house training packages and
supply Equpment and spares .
Any Queries or questions please do not hesitate
to contact us .
Basic welding Ltd : Tel 0161 273 8150