Anyone got any (useful) advice for Drilling out a Bottom bracket?

Damned Campag 90's cups made of cheese! Trying to get a 90's sealed veloce BB out. Aluminium cups have sealed to the steel frame (Grrr!). Got the the right tool- just mashed the teeth off.

Only option is to drill it out. I'm aiming to place a few holes round the axle so I can pop it out and then go in with a Coping saw

Lots of swearing involved as well

Cheers, consider the caustic soda if I can't drill through in a day or two. Am trying to stay as close to the axle as possible and away from the shell. Have a feeling the whole process will take a while :(

I've done Caustic soda before but from the inside of the frame and it barely touched the paint;

pour it down the seat tube and position bike over a plastic tub. It will take longer than submerging the BB in it but will happen eventually. There will be some slight damage to the paint on the bottom of the bb shell maybe but nothing major.

I would definitely not choose drilling or cutting it out over this.

Oxy acytalene will burn that sucker out pretty quick. You can then fold it in on itself and pull the rest out

Never tried this but would a hole saw be the thing to use

It's a beautiful paint job so I've opted for the best of both worlds. Drilled a couple of pilot holes in one side of the cups and poured some high strength caustic soda solution in there. Lots of rewarding fizzing noises going on so far...

Ninja!

Nice to have a ray of hope. The peach and purple paint job is fantastic and I'd like to keep it that way :)

Ahen,

anyone ever got a little bit bored and resorted to using one shot? (91% Sulphuric acid according to the guy in the shop)

Drill 2 holes and try turn it using them rather than the tool?

What's the evidence that acid would work? In any case, be extremely careful if you do use it. If there's any moisture in the BB shell it could go badly wrong.

How do you stop the sulphuric acid from eating the steel frame?

I was wondering that. Weirdly it seems that at high concentrations it forms a protective iron sulfate layer which prevents further corrosion, but I wouldn't trust that that would happen.

Hmm,
I've yet to see anyone offering a bottom bracket thread sulphating service.

Pin spanner / holes was the first thing I tried. No chance...

I'm going to stick with the pilot holes / caustic soda for now. I considered dripping the sulphuric into the axle itself to see if I could then stop the rot before it got to the threads; but don't want it to go horribly wrong so opted to save that stuff for the last resort- The guy did warn me that any slight drop of water would F#ck it like a Gremlin...

As to acid in the 80's... Heh heh heh... Microdots were better.

Varonha Frameworks will burn it out for £20 (if you can be bothered to take it to Hither Green).
https://www.varonha.co.uk/repairs/

Liking the big drill he's using on that BB :)

Used to live out that way a long long time ago... Quite far from me now (in both space and time)