Cracked Wheels - Don't settle for substandard "repairs"

Cracked Wheels - Don't settle for substandard "repairs"

What do we mean by substandard repairs, well typically with crack repairs the quickest, most profitable route is taken with little to no regard for the safety of the person using the wheel.  Sadly the folk repairing wheels in this way are not the ones to blame, the customers who see little to no value in a proper repair are the reason this has become the norm, typically not wanting to spend more than £20 to "fix" the issue.
The net result of this is shown here.
So what happened here? Well, the crack was welded over, a fairly normal occurrence, but unfortunately the crack reappeared.  This was once again welded over the top and again, the crack reared its ugly head.  There was seemingly no other way to fix this crack than the application of some epoxy based adhesive or sealant.  Making our job of fixing it even more joyous.

What can we do about this? Firstly, understand that a crack repair carried out correctly takes time and unfortunately with time, comes cost.  Now, we're not talking fortunes here, but for the sake of a little more than the typical "repair" price you can have it carried out in such a way that the crack will not reappear down the line and your wheel will be safe to drive on once again.

Obviously with the change in molecular structure the wheel will never be back to it's original strength after welding, but with proper filler rod selection and careful control of heat whilst welding, you should never have an issue with the repaired crack again.  This is why we do everything we can to ensure the wheel you receive back from us is safe to use.

What we are going to do in this post is detail the procedure, taking you through it step by step to show why there is a difference in price and the way we approach something so safety critical.

So upon receiving the wheel, we strip any paint, powder or other coating, in this case anodising, from around the crack and a little beyond to where we think the crack may extend to.
For this exercise we're using an original early 70's magnesium Porsche Fuch.  Highlighted above is the crack through one of the "petals", this was virtually impossible to see from the front but sadly that was not photographed.

After stripping the anodising and black paint from the area, we use the TIG to identify the full extent of the crack.  It's not the perfect method, but requires a lot less clean up and hassle of using a crack detection dye.

Nearly 50 years of use and abuse, and this magnesium, although beautifully polished immediately showed up signs of porous material and other contaminants that had worked their way into the crack.  However, it did allow us to find the end of the crack which was subsequently stop drilled to prevent any further ingress throughout the spoke after the repair is complete.

Now we know the extent of the damage, it's time to begin removing all material that could be affected, either weakened due to the forces that caused the crack or movement and contamination that has come about since the crack occurred.

Having roughly dug any and all affected material out, welding the gap up like this would require a lot of unnecessary heat and inconsistent penetration.  As such, we break out the die grinder and bevel the edges.  This allows the use of much less heat, full penetration and a gradual blend between the new material and the old.

With the bevels now taken care of, we can begin to do a final clean with a wire brush and finish up with acetone and a wipe down.
Welding the wheel is a multi pass process, an initial root pass to join the two beveled edges together, a hot pass to really fill the joint and get the filler to flow with the original and a cover pass, shown above that helps drag any contaminants up and out of the repair where it can then be removed and dressed off.

The initial grinding removes a lot of the excess material very quickly, but once it has been knocked down a little more finesse is required to try and ensure you follow the original contours of the wheel.  A little more time and a quick run through the scotchbrite wheel and you end up with something like this....

The entire process is carried out from the back of the wheel too for obvious reasons but the result is a clean and properly repaired wheel.

The wheel was then sent to be polished properly, after the mirror polish was complete the wheel is then sent to be anodised back to it's original finish before having the black paint around the petals reapplied.  Ultimately returning to the customer as if nothing had ever happened in the first place.

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