removing broken (Clarks-pah!) taps

[nellway]

Malcolm will laugh as he told me ages ago that buying tools from Machine Mart was A Very Silly Thing To Do.

I was tapping out a 1/4 inch bolt hole in the chassis over the weekend and the sodding Tap snapped - this is in a place that cannot be cut out easily and re-welded.

Can anyone give me any tips for how to drill out or otherwise remove the blasted thing?

I also discovered at the weekend that the torque wrench from the same place doesn't work - so that's going back.

Looks like I'm going to be spending quite a bit on expensive tools in the next few months.

On the bright side I did get the steering rack onto the Aston - and when I've got the new gaiters on the king pins the front wheels will be back on - big psychological step forward.

 

[rtbcomp]

Can you get a small punch on the flutes and drift it round?

 

[fingers99]

You can buy very expensive tap removal tools. But, as above, or sometimes you can get a pair of small needle nose pliers -- or even circlip pliers in there, sufficient to work it out.

Failing that, you'll never drill it out (well, maybe, with a short cobalt drill) unless you can get an oxy torch in there to anneal it. Try TIGing something to it?

Taps are very fragile -- I don't think the MM ones are any different. Usually breakeages are due to cack handedness on the part of the operator (myself included).

If the worst comes to the worst, bash it out with a drift and helicoil.

 

[nellway]

Most of my mistakes on the car are due to my own stupidity..

This was a particularly awkward job done lying on my back under the car.

I can't punch it out as there is no space on the upper side for it to go.

We did try the long nose pliers, but the damn thing wouldn't budge.

One technique that seemed to work - but will take bloody ages. I put the diamond engraving bit in my Dremel and started to grind away at one of the flukes. I thought if I could shape a depression into the broken end I could then use a cobalt drill bit.

At the moment, because the broken end is sloped, any attampt to drill results in the bit sliding into the seat metal.

An interesting point. We had the chassis galvanised which is why the captive nuts and fixings all need tapping out. The ones on the right side of the car have been easy, the ones on the left have all been a real bugger.

Did the electrolysis process in the galv tank cause one pole to attract more zinc than the other, or make the zinc harder?

One for the physicists to answer.

 

[rtbcomp]

.........Did the electrolysis process in the galv tank cause one pole to attract more zinc than the other, or make the zinc harder?

One for the physicists to answer.

Galvanising is usually a hot-dip process, ie they dip the chassis in molten zinc, not an electro-plating process.

Perhaps by the time you got round to the left hand side the tap had worn?

 

[Hitch]

The good quality taps seem far more able to cope with misuse than the cheaper ones.

Is it an option to bang a bit of weld over the hole and redrill it to one side slightly?

 

[Ashg]

heat the area up then have a go with the circlip plyers again the mild should expand more quickly loosening up the broken bit.

 

[jugs]

heat the area up then have a go with the circlip plyers again the mild should expand more quickly loosening up the broken bit.

Put some copper grease in when hot (lots of smoke) it thins down & capilery action should get some betwen the 2 metals.
In future only use - ground thread HQS or HSS taps -not carbon steel.

Good luck with it.

 

[JimM]

Is the head of tap big enough for you to weld an extension to ?? (Assuming taps are of a weldable material ?)

 

[snowcat]

there sometimes crack if you hit the flutes on one side, either that or plasma (if you have one) and chop straight down the center, gas is option 3, got quite good at removal when I was winding lots of M24s through with a windy gun

 

[Robotstar5]

An interesting point. We had the chassis galvanised which is why the captive nuts and fixings all need tapping out. The ones on the right side of the car have been easy, the ones on the left have all been a real bugger.

Due to the shape of a chassis it was probably dipped lengthwise, ie right side lowermost, as it was lifted the left side would have drained longer, probably through the holes on the right side causing more galv to deposit in the threads?

Well that's my theory until a better one comes along

 

[nellway]

Thanks chaps - I will certainly try the heat/oil/circlip plier - I've ground quite a groove with the engraving tool so perhaps a sharp bang with a thin punch might sheer it.

I've still got a few holes to clear out - for exhaust mounts and brake pipe clips mainly - but this one is for the antiroll bar bracket so I need to have it pretty well spot on.

The galv on the right is certainly thicker than that on the left so you may well be right about dipping the chassis sideways.

I may just post a similar thread on the Landrover forum - they galv loads of chassis.

 

[hareng]

Failing that break the tap up inside the hole with brute force