It keeps cropping up on here – the dreaded corrosion on 108s.
I’m in my 5th year with a set of 108s and they have survived without corroding. The main reason for corrosion is the construction of the wheels from 2 separate parts. It is the joint between the two parts - the rim and star spoke (and indeed the connecting bolts) where the corrosion usually starts. This is generally caused by water getting into the joint and due to the slightly acidic nature of the water (rain water, salt spray from treated roads etc) galvanic/catalytic corrosion occurs – this is an electrochemical process in which one metal corrodes preferentially when in electrical contact with a different type of metal and both metals are immersed in an electrolyte (the rain water etc). Brake dust can make this worse as the glue that bonds the pad components is contained within the brake dust and itself can create a very mildly acidic solution when combined with water.
To prevent this a seal must be created between the two parts to stop the ingress of water and allowing the electrochemical process to start. On mine – when new and being aware of the problem – I removed the wheels and thoroughly cleaned and dried them. When dry I applied a thin bead of silicone sealant between the outer star spoke and the main body of the rim to prevent water getting in – you can’t see this from outside the vehicle from any angle. I thought about doing the outer joint but to date have had no problems here.
When cleaning the car it is essential to ensure that the rims are dry when you park the vehicle as water will drain to the lowest point within the rim and generally sit at the joint between the two components and as there may be some residual cleaning agent in the water and an ideal environment is created to start the dreaded corrosion.
I hope this helps anyone thinking of fitting or just maintaining their 108s.
I’m in my 5th year with a set of 108s and they have survived without corroding. The main reason for corrosion is the construction of the wheels from 2 separate parts. It is the joint between the two parts - the rim and star spoke (and indeed the connecting bolts) where the corrosion usually starts. This is generally caused by water getting into the joint and due to the slightly acidic nature of the water (rain water, salt spray from treated roads etc) galvanic/catalytic corrosion occurs – this is an electrochemical process in which one metal corrodes preferentially when in electrical contact with a different type of metal and both metals are immersed in an electrolyte (the rain water etc). Brake dust can make this worse as the glue that bonds the pad components is contained within the brake dust and itself can create a very mildly acidic solution when combined with water.
To prevent this a seal must be created between the two parts to stop the ingress of water and allowing the electrochemical process to start. On mine – when new and being aware of the problem – I removed the wheels and thoroughly cleaned and dried them. When dry I applied a thin bead of silicone sealant between the outer star spoke and the main body of the rim to prevent water getting in – you can’t see this from outside the vehicle from any angle. I thought about doing the outer joint but to date have had no problems here.
When cleaning the car it is essential to ensure that the rims are dry when you park the vehicle as water will drain to the lowest point within the rim and generally sit at the joint between the two components and as there may be some residual cleaning agent in the water and an ideal environment is created to start the dreaded corrosion.
I hope this helps anyone thinking of fitting or just maintaining their 108s.
