Page 48 - Australasian Paint & Panel Jan-Feb 2023

Mixed Material Repairs
48
PAINT&PANEL JANUARY / FEBRUARY 2023
WWW.PAINTANDPANEL.COM.AU
WHERE ARE THE MATERIALS
USUALLY LOCATED?
Now we are seeing alu-
minium, carbon fibre and
plastic in the body struc-
ture of the vehicle. Parts
that are lighter than their pre- decessors are used in areas that are traditionally the heaviest e.g the engine area. This helps with axle load distribu- tion and better driving performance and balance.
HOW ARE THE MULTI MATERIAL
PARTS JOINED TOGETHER?
Traditional joining methods like Squeeze Type Resistance Spot Welding and GMA (MAG) Welding cannot be used when joining different types of material like steel and aluminium. Due to the com- plexity of the product, they are often joined through adhesive bonding with the addition of a mechanical fastener like blind rivets or punch rivets.
WHAT KIND OF TOOLS ARE
REQUIRED TO MAKE REPAIRS?
There are a number of specialised tools required to complete repairs on a multi material vehicle. They range from punch rivet guns and adhesive application guns, to explosion proof vacuum clean- ers. Each of the manufacturers may have their own version of their ‘specialised’ tooling which presents a challenge for the bodyshop business if they are repair- ing many different brands.
DO YOU NEED A DEDICATED
REPAIR AREA?
Yes, there are specialised areas required when repairing new complex vehicles. These areas can be curtained off from the rest of the work area or even a tem-
perature controlled, sealed ‘booth’ that eliminates galvanic corrosion and cross contamination with other vehicles being repaired.
ARE THE SPECIAL DAMAGE
ANALYSIS PROCESSES
REQUIRED?
Yes, when analysing damage on a vehi- cle with many different substrates, par- ticular attention needs to be paid to the varying characteristic of each of the products. Steel, aluminium, and carbon fibre all contribute in different ways to collision energy management.
CAN WE STRUCTURALLY
STRAIGHTEN MULTI MATERIAL
VEHICLES?
Structural straightening is very limited, if allowed at all. This is due to the threat of collateral damage occurring to other parts of the structure because of the increased force applied. This is a real concern, as this potentially breaks adhesive bonds on other joints within the body.
WHAT IS A THERMITE REACTION?
An exothermic reaction occurs when iron
oxide (rust) and aluminium powder come together in the presence of an ignition source. It burns at spectacularly high temperatures, as hot as 3,500 degrees Celsius, which is hot enough to melt steel. The collision repair industry is tra- ditionally classed as zone 22 hazard with very little chance of a thermite reaction occurring during repair, however meas- ures need to be taken to ensure separa- tion of these two substances. There has been at least one workshop mishap in Australia where the use of a bench grind- er produced the ingredients for a thermite reaction with the resulting fireball leav- ing the operator with serious burns.
IS SPECIFIC TRAINING
REQUIRED?
Training on joining and/or replacement of two different substrates is very important as accurate repairs to these products en- sure the vehicle will respond to a second collision in the appropriate way.
Familiarising technicians with multi- material vehicles and establishing a proper and comprehensive repair process takes time and commitment. I-CAR Australia offers a range of courses designed to upskill collision repair businesses to ensure their team has the knowledge, skills and confidence to correctly repair a vehicle, regardless of material make up.
You have to do your homework to safely repair the Q7 which made from predominantly aluminium.