By now, many of you know that one of the downside of these beautiful wheels is the tendency for cracks to develop between the lug holes and the center bore hole. Overall consensus is that using a pneumatic tool to screw in lugs and over-torquing will lead to cracks developing. However, I feel that there is more to that than just over-torquing. I strongly believe that these cracks are multi-factorial, with over-torquing being secondary to a variety of different fracture-leading causes.
Instead of having another thread to complain about the cracks, I thought of starting a controversial one on the repair of these cracked inner faces. Many posts in the past have stated that once a crack is developed, then the wheel is no longer repairable and is junk (only worth its weight in scrap price). My question to you all is, is it really?
I bought my set requiring a refurbishment in 2006. I spent a year tracking down a set that was not cracked. I've had seen several sets during my year of searching that had various degrees of cracks. Luckily, I found one complete set that just needed paint and polish -- no cracks. If you're interested in the full details of that whole ordeal, its in my old thread found here: http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1285099-amg-3-piece-wheels-revisited.html
Now, back to the question. Can the cracks be safely repaired? Many say no.
I would be curious to hear why those who say no believe that. I must say that I am also from the camp that says that its difficult to repair these cracks in a safe manner. However, I'm hesitant to flat out say NO, it cannot be repaired in a safe manner. I just don't know how just yet.
In my field of work, I deal with components made out various metals, alloys and ceramics. I have to be familiar with the properties (tensile and yield strengths, hardness, fatigue, etc) of these materials to minimize any risk of failure as it can be cata$trophic when it does. Sometimes we have to modify components or make them when manufacturers stop production of an item. If we have to cut metals and weld them, we use laser welding. I never thought of this method being used in repairs of cracks in wheels. So I started to investigate and looked into this a little more and sure enough, I found publications on use of laser welding in repairs of aluminum and steel wheels.
This brings up questions to those who say "no, that once these wheels have cracks, they can no longer be repaired". Obviously, not all welding processes are the same. There are different techniques and ways of welding metals and alloys. Some are more precise than others. So I would like to hear some opinions and thoughts on this topic. Everyone can have an opinion, but I would like to hear thoughts that can be backed up with science and facts.
Oh by the way, I realized I reached 8000 posts. It only took me 11.5 years to get there ;-)
For those interested in reading more on this issue, here are some good links:
Crack Repair
Materials Research - Cracking susceptibility of aluminum alloys during laser welding
http://www.microjoining.com/docs/1366134548_microtip_weld_cracking.pdf
http://www.aws.org/rwma/docs/winter13/RWMA_.pdf
Instead of having another thread to complain about the cracks, I thought of starting a controversial one on the repair of these cracked inner faces. Many posts in the past have stated that once a crack is developed, then the wheel is no longer repairable and is junk (only worth its weight in scrap price). My question to you all is, is it really?
I bought my set requiring a refurbishment in 2006. I spent a year tracking down a set that was not cracked. I've had seen several sets during my year of searching that had various degrees of cracks. Luckily, I found one complete set that just needed paint and polish -- no cracks. If you're interested in the full details of that whole ordeal, its in my old thread found here: http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1285099-amg-3-piece-wheels-revisited.html
Now, back to the question. Can the cracks be safely repaired? Many say no.
I would be curious to hear why those who say no believe that. I must say that I am also from the camp that says that its difficult to repair these cracks in a safe manner. However, I'm hesitant to flat out say NO, it cannot be repaired in a safe manner. I just don't know how just yet.
In my field of work, I deal with components made out various metals, alloys and ceramics. I have to be familiar with the properties (tensile and yield strengths, hardness, fatigue, etc) of these materials to minimize any risk of failure as it can be cata$trophic when it does. Sometimes we have to modify components or make them when manufacturers stop production of an item. If we have to cut metals and weld them, we use laser welding. I never thought of this method being used in repairs of cracks in wheels. So I started to investigate and looked into this a little more and sure enough, I found publications on use of laser welding in repairs of aluminum and steel wheels.
This brings up questions to those who say "no, that once these wheels have cracks, they can no longer be repaired". Obviously, not all welding processes are the same. There are different techniques and ways of welding metals and alloys. Some are more precise than others. So I would like to hear some opinions and thoughts on this topic. Everyone can have an opinion, but I would like to hear thoughts that can be backed up with science and facts.
Oh by the way, I realized I reached 8000 posts. It only took me 11.5 years to get there ;-)
For those interested in reading more on this issue, here are some good links:
Crack Repair
Materials Research - Cracking susceptibility of aluminum alloys during laser welding
http://www.microjoining.com/docs/1366134548_microtip_weld_cracking.pdf
http://www.aws.org/rwma/docs/winter13/RWMA_.pdf