Cracked alloy - can you re-weld a weld?

[Martyn76]

Hi,

My BMW failed it's MOT yesterday due a cracked alloy, the crack is on an existing weld, is it possible (or good practice) to re-weld the crack or am I looking at needing a new alloy?

TIA

[julian64]

Martyn76 said:

Hi,

My BMW failed it's MOT yesterday due a cracked alloy, the crack is on an existing weld, is it possible (or good practice) to re-weld the crack or am I looking at needing a new alloy?

TIA

I find this difficult to answer as I've had mixed success with welding alloys. I sucessfully stich welded a small hairline crack using TIG and its still passing MOT's with no problem, but I also had some disasters with alloys just falling apar tin front of me when welding.

I think the problem is the multitude of various alloys used and some are amenable and some aren't complicated by which of the many alloy filler rods you are using.

I think its possible but requires quite a lot of experience.

Rewelding a previous weld is entirely possible

[Martyn76]

julian64 said:

I find this difficult to answer as I've had mixed success with welding alloys. I sucessfully stich welded a small hairline crack using TIG and its still passing MOT's with no problem, but I also had some disasters with alloys just falling apar tin front of me when welding.

I think the problem is the multitude of various alloys used and some are amenable and some aren't complicated by which of the many alloy filler rods you are using.

I think its possible but requires quite a lot of experience.

Rewelding a previous weld is entirely possible

Thanks for the reply, that's good to know it's possible, will be getting it done an alloy repair place by someone who knows what they are doing.

[yeager2004]

I had a cracked alloy a while back. I phoned a few local wheel refurb places: the first place outright said he wouldn't do it. The second said he could do it , but wouldn't!, the third offered to do it, but by the time he priced the repair and then a wheel refurb it was well over £100. I found a new wheel on eBay for not much more.

[stevieturbo]

impossible to say without seeing the damage, and the weld.

But many wheels are repaired all the time without issue. And yes you can re-weld a weld, and often this process of building up is necessary due to poor or dirty castings.

But a lot of the time too, it's just as handy to seek out a replacement wheel

[softtop]

I have just been through this, the cost of a second repair went up and I bought a second hand one off Ebay for the same price, and it came with a tyre!

[Martyn76]

Thanks all, I have looked for a replacement alloy, it's for a BMW E90 and as it's a staggered setup being the rear it's more costly, ones on Ebay are either cheap with cracks and\or buckles or several hundred £s.

I'll see what the wheel repair place says, they repaired these wheels in the past for me although this is the first time I have had one of the welds crack.

Winters are on now and MOT re-test passed so got a a bit of time to sort it out until next March.

[Pica-Pica]

I would not weld an alloy, and certainly not re-weld one. I am fussy/nervous about these sort of things.

[stevieturbo]

Martyn76 said:

Thanks all, I have looked for a replacement alloy, it's for a BMW E90 and as it's a staggered setup being the rear it's more costly, ones on Ebay are either cheap with cracks and\or buckles or several hundred £s.

I'll see what the wheel repair place says, they repaired these wheels in the past for me although this is the first time I have had one of the welds crack.

Winters are on now and MOT re-test passed so got a a bit of time to sort it out until next March.

can't be that difficult to find some second hand wheels.

A friends wife bounced his BM off a kerb a few months back, damaged two left wheels and one of the tyres. Diamond finish, so not repairable...well not really repairable anyway lol.

A couple of hours on the phone and he'd found two wheels at a localish breakers yards. New tyre, two wheels, job done.

BMW's are very plentiful both on the road and crashed. So wheels should be fairly easy come by with a little bit of effort

[Tony1963]

My tip used to be: buy a set of four off eBay, then sell the three you don’t need, but sell them individually. You’d make money out of it. I don’t know if that’s still the case, so have a look.