Postby J44EAG » Mon Jan 01, 2018 1:49 pm
I have an aluminum bodied MY 2004 X350R and have only had one very small area of corrosion and paint bubbling to tackle. I can tell you it is a lot easier to treat than a steel car where one can suddenly find oneself having to deal with panel perforation!
Some eighteen months ago, I found a small patch of paint bubbling on the off side front wing just in the area one would perhaps find a mud flap located. Fortunately I didn`t have a mudflap to remove or gritty paint abrasion to deal with.
My experience with dealing with ali corrosion comes from my time in the aircraft air-frame repair business so I applied an identical procedure to deal with the X350 paint defect. I used a small grinder/sander which has just 25mm diameter garnet sanding discs of various grit grades. It also has a variable speed control. To begin, the panel was water washed, then wiped with iso-propanol alcohol as used by professional paint sprayers. This gets rid of any panel grease.
Using the small sander grinder with a P180 grit disc, soon had the bubbled paint off back to bright metal. The edges of the remaining paint were then flatted down to remove grinding scratches and taper the paint layers down into the opened up area. (Dish fashion) It was then dusted off with a new, soft and clean paint brush. Again iso-propanol wiping took place. That done, the existing paint was cleaned up with a soft cloth and G3 rubbing compound, water washed, compressed air dried and panel wiped again and left to flash dry. Masking was applied around the area as required but not around the opened up repair area. AT NO TIME WAS CARBORUNDUM BASED W&D PRODUCTION PAPER USED FOR FLATTING AT THIS STAGE.
Mixing a small quantity of aircraft grade alodine based two part etch primer (Upoxy Super-etch), it was then spray applied using a small compressed air powered spray gun fitted with a tight fan needle and nozzle. The primer was sprayed onto the opened prepared metal and overlapped onto the undamaged surrounding area by about 25mm. Three coats of etch primer were applied and left to air dry for about three hours in the sun.
Once dry the primer was water wet flatted with P1500 W&D paper to a smooth orange peel free finish. Great care was taken to ensure the primer was not over flatted to the point that the W&D paper broke through back down to the metal. Carborundum contacting aluminum would cause future corrosion issues! The wet flatting produced a smooth primer surface and removed the primer dust edges to nothing. Water washed and then buffed up with Faracla G3, the primer blended level to the undamaged paint. Water and panel wiped again and allowed to air dry the repair was ready for colour top coat.
For small repairs, I buy specially mixed Holts areosols from Halfords. Colour matching is perfect on my PEF coded XJR. Three or four coats are sprayed over the repair, again overlaapping the primer edges by about 25mm. A spray dust edge will result. Leave to air dry or lightly assist with a small infrared lamp for 24hrs. Don`t rush this stage. Once the paint is hard, wet flat with P2000 W&D paper. Water and panel wipe wash again. Buff up with a soft cloth and G3. This should blend the new paint into the old and promote a high gloss finish. Panel wipe again and spray three coats of clear coat onto the repaired area and 25mm onto the old paint. Again let this paint air dry or assist with an infrared heater. When hard, wet flat with P2000 W&D paper, polish up with G3 to a mirror finish and apply a coat of your favorite wax polish. Job done with hopefully the repair being undetectable.
Give me an aluminum car any day in preference to a steel one! Its a lot less potential maintenance grief!
Mike K
X350 Co-ordinator
2004 XJR
Hello everyone
Mike.
