Best Penetrant Oil?

[CDollarsign]

I have a bb cup stuck, looking for the best penetrant oil. I have read that half acetone half automatic transmission fluid is better than stuff like liquid wrench. Anyone use it? How bad is it on paint?

I assume acetone doesn't mean nail polish remover?

[AngryScientist]

kroil is the best i've come across for penetrant.

is it a ST bottom bracket cup stuck or an external type? what are the materials we're talking about?

[Peter P.]

Acetone won't do squat-it's the fastest EVAPORATING solvent available. Says so right on the container.

Liquid Wrench, PB Blaster, CRC Freeze-Off, or plain Coca-Cola (just be sure to rinse thoroughly).

Your ally is patience. You may have to reapply daily for a week or more until your solvent of choice works its magic.

[zmudshark]

From my experience, Kroil is the best, PB Blaster is next, if you can't find Kroil. The molecule size of Kroil is smallest of the commercial products, so it penetrates better/faster.

As mentioned, is it an old square taper cup, or an external? There are other tricks.

[Cicli]

Kroil or better than that, A 50/50 mix of acetone and ATF.

[CDollarsign]

It's a square taper campy bb cup. Side without the lock ring. So i assume it's Al in a steel frame.

[oldpotatoe]

Originally Posted by CDollarsign

It's a square taper campy bb cup. Side without the lock ring. So i assume it's Al in a steel frame.

Like this? Remember direction, English(left threaded), Italian(right threaded), French(like Italian, right threaded). Get/use a proper tool also.

[ultraman6970]

What potato says... if you have no tool you can use a vice and use the frame to torque that thing out.

The other option is to use the bolt technique and a giant tube wrench plus a 2 feet pipe attached to the wrench.

[paredown]

Originally Posted by ultraman6970

What potato says... if you have no tool you can use a vice and use the frame to torque that thing out.

The other option is to use the bolt technique and a giant tube wrench plus a 2 feet pipe attached to the wrench.

although you have to be super careful using the vice method, it does let you use the length of the frame for leverage.

As Auld Spud says, just be very sure you are turning it in the proper direction.

Question for the crowd--does Kroil stink as bad as PB Blaster? If not, it's on my list...

[CDollarsign]

I don't have the tool so took it to the LBS. They were using one of the spanner deals. Side with lock ring came out with no problems whatsoever.

For the penetrating oil, should i clean up all the grease around the threads on the inside? I would think that would maybe block it from getting around the cup.

[gdw]

I've used the acetone transmission fluid mix and it lives up to the hype. The bolts it was used on weren't painted so I don't know if it will damage your bike's finish. Get the acetone from a hardware store not your wife's beauty supplies.

[zmudshark]

I have used a long bolt with a couple of fender washers to hold the tool against the fixed cup, and then used a Park FFS-2 as leverage. Never failed.

Be sure you are going in correct direction, lefty loosie for Italian, righty loose for English!

[Gummee]

I've used a Makita cordless impact wrench to wonderful effect if you have a BB that has splines.

Sure beats a 3' breaker bar and standing on the #$%$ thing.

...and I've had more than a few of those over the years!

M

[Dirtdiggler]

I just searched Acetone and ATF 50/50- wow this is no joke.. Gonna mix up a batch and try this out.
Thanks

[CDollarsign]

I wonder what I would use to apply the 50/50 soultion?