Rethreading coax thru capping

[Broadback]

I have 2 coax cables under capping buried in plaster. Though stiff they can be pulled. I need to replace these, and suggestions as to any method of easing them through? Thanks.

[Chris Bacon]

Pull the cables upwards, not down. Pull what's in there out first, leaving some strong but thinner wire in the capping to pull the next lot through. Work this up and down to get rid of debris. Attach the new cables, make sure the ends are tapered (melt and "form" the ends if need be to make them tapered) and pull the new cabling up. You might be able to shake some talc down the hole after drawing the cable in in a short way (for lubrication). Don't tape the cables together, but have an assistant to feed them in.

[Ian Stirling]

Alternatively, there are cable pulling lubricants available. Though water based lubricating jellies usually sold for other purposes work too. Don't use oil based of course.