Mashed crank dust cap - safe removal?

I have just finished building my first fixed build, looking nice and shiny, but the BB is creaking as i pedal (not the pedals or chainring - both have been tightened) so i've decided to take a look...

... But the plastic dust cap on the drive side of the Campy cranks has been mashed up and is ingrained into the threads of the cranks, so no chance of getting a crank puller in there. The previous owner attempted to get it out with a screwdriver, but it's mostly still there, and i'm worried that a screwdriver could permanently damage the thread and leave me with an unremovable crank, which would be worse than just a creaking BB. Any ideas about getting it out? And has anyone else already had this problem? All advice welcome :) Thanks,

Paul

Hmm.

It's only plastic so it should come out with no real bother. Perhaps try getting a tiny little watchmaker's screwdriver and prise it out little-by-little.

I wonder if there's something that could dissolve it... acetone perhaps. It might just leave a mess in your crank hole (oo er) though.

The dissolvey option crossed my mind, but not sure what would work. Also contemplated melting it, but quickly dismissed that... blackened cranks :P

You can polish the black off. I don't know if it'd work very well though - even when melted it'd be very viscous and if it caught fire it'd possibly leave a nasty residue.

If you've got the other dust cap off, see what dissolves that. Acetone aka nail varnish remover might well do it. If not, try cellulose thinners (from motor factors).

Some are metal, others are plastic. Any idea which..?

if its plastic then it will 'break' if you give it a good rogering with a large screwdriver...

if its metal, then gentle rogering...

... But the plastic dust cap

:P I know, you'd think so, but it just bends and comes of in small bits when i try to get bits out with a screwdriver. Most of it is out, but it still clings to the thread of the crank, and doesn't want to come out in one piece. I'll try and get a picture of it to show you the problem...

Just tried the acetone, worked pretty well, just scarping out the stringy bits of plastic, cheers frink :P

ultimately don't worry about knackering the thread - if you need to get it off to use the frame you'll and there's no other way - you'll have to do it- and you can use a forked wedge to take it off (not ideal for any BB - but i 've never seen harm done)if thread knackered - you can still use it and take it on/ off bikes .

if plug is plastic and nothing else has worked then heat will melt / burn it out

I'll have to wait and see, need to get a 15mm socket wrench to get the bolt out first anyways.

Sure it's 15mm? All the old-style nutted BBs I've worked on have been 14mm, and I needed a deep socket because standard ones were too wide to fit down the hole.

I'm probably wrong though, most of my BBs have used allen bolts.

Just checked it with me caliper, tis 14.83mm exactly lol, will need to make a trip down to halfords... Allen bolt ones are so much easier...

The answer to every question: Dremel it.

Drill two 2-2.5mm holes, then use the pin-spanner, or the other side of the Shimano chainring bolt spanner, or some bent-nose pliers
:)
PlusGas always helps

just had same problem - acetone - who'd have thought it?
worked a treat! thanks