old frame with potentially stuck BB

[mig]

i've been given an old frame for possible use in the summer on the road. i suspect that the BB is original and has maybe been in there 20 years or so.

what should i lob down the seat tube before attempting to avoid a hernia in getting it out in a few week's time? bit of unused engine oil? gear oil? ACF-50?

[hamster]

PlusGas works wonders - much thinner than others (including WD40). As you suggest a good dose down the seat tube and a week to pickle should help a lot.

[fausto99]

+1 for Plus Gas

[barrym]

+1 for plus gas too, but diesel also 'creeps' well if you have any to hand.

[Brucey]

some solvent (like paraffin) and some oil is a good mix. You can use a more volatile solvent but it will just evaporate more quickly.

cheers

[fausto99]

Just thought, what material is the frame? Plusgas works very well with steel to steel but I had to use ammonia to free an alloy seatpost in a steel frame.

[mig]

yes it's tange steel. seems pretty solid stuff and worth saving if i can.

[Gattonero]

Soak it with PlusGas or RustOleum, make it a few times over several days.
Then strip the bike, put it on the floor, secure the extractor on the Lh side (usually is the removable BB cup) with a bolt and put the frame on the floor (maybe a block of wood under the BB) while someone holds the frame you can crank it up with a long spanner. Mind you, you only have to "break the seal" with about 1/2 turn, then you have to start backing off the bolt that is holding the extractor on the BB axle.