Any recommendations - induction coil heater for seized bolts

[25th QV]

I've run out of techniques to remove a long M12 through bolt that clamps an alloy wheel carrier hub around a suspension strut due to galvanic corrosion.
I managed to get the other side out eventually with a rattle gun but boy was it tough going - white powder everywhere from the corrosion.

On this bolt, it was even more stubborn until eventually the rattle gun rounded the head of the bolt. I've tried s blow torch but can;t get it hot enough and even destroyed a sturdy puller tring to force it out from the other side. Loads of pen fuild, shocks with a lump hammer, punches etc - none had worked.

As a last resort I was thinking of trying one of those induction coil heater devices, but they look quite expensive, although there are some cheaper ones on Amazon.

Has anyone had any experience with these, do they work and are the Amazon one's worth trying? Should I aim for a minimum power rating?

Any guidance or advice appreciated as after 30 years of messing with cars, this is the first time I've come unstuck

[InitialDave]

I bought a cheap made in China one for £100 ish a few years back.

Works just fine.

I'm sure it'll die at some point, but I'll just buy another.

No problems recommending them as another arrow in the tool quiver.

[25th QV]

Thanks - are they as effective as they look?

Was looking at this one.... https://www.amazon.co.uk/Hand%E2%80%91Held-Electro...

[InitialDave]

Mine is the same as this.

https://amzn.eu/d/7VgjIM5

Amd yes, they're very effective, can put plenty of heat into a bolt.

[yeager2004]

I'm tempted by one of the heaters. There's a big difference in costs, the Draper one is well over £500.

I'm wary of cheap tools, but for occasional use maybe it's not worth saving up for the Draper. How much better can it be?

[jfdi]

Draper is hardly a Snap-on quality tool manufacture. In my experience most of their tools are generic Chinese made tools with the draper name on them.

[Triumphantic]

There's a 1000w one on Aliexpress at the moment for £65, no idea on quality though

[25th QV]

Just a thought - a quick google suggests cherry red for mild steel is circa 800 degrees C.

The melting temperature of aluminium is 660 degrees C.

When using heat, do I have to get it cherry red to make it worth while and will these induction coils get them this hot?

If so, it will likely damage the alloy housing the bolt id seized into will it not?

If I get it 'smoking hot, but in no way glowing at all, will this be enough heat to make a difference.

This stick bolt is beating me right now as I just machined a blind bolt out of tool steel to screw onto the bare threaded end of the bolt that protrudes through the other side of the alloy housing in an attempt to crack it free. After about 20 seconds on the rattle gun it sheered the threads on the bolt rather than crack if free from the housing. I then drilled and pinned the new home made bolt like a cotter pin, using a drill pit as the pin, but thin then sheared the M12 bolt in half.

I'm really struggling with this one for sure!!

[Shedding]

Porsche hub carrier? Might it be easier to buy a used one on ebay?

[E-bmw]

Personally if I had gone through the steps that you have done I would be drilling the bolt core out progressively larger until it is possible to get a tap in there.

[25th QV]

Had to pull the full hub and strut , mount it to a fixture using the brake caliper bolt holes and weld a long bar to the rounded end of the nut. With some gentle heating of the carrier and some solid blows to the lever bar, it eventually cracked and began to rotate back and forth a few degrees at a time. Over about an hour I eventually got it free enough to drift out from the other side.

Copper grease is our friend.

[E-bmw]

Well done for getting it off.

Just remember if gently persuasion fails, there is always brute force & ignorance.