"peter" wrote in message
ups.com...
Maybe I dreamed this, but I'm sure I remember seeing advertised a
gadget in two parts which you could place either side of a surface to
show you where a drilled hole will exit on the blind side. In case I
haven't described that very well, you would have someone hold one half
of the tool at the point where you intend to drill, then you go round
the other side with the other part of the tool and move it around until
it indicates, by light or sound, the point where the drill is going to
exit. Anyone know what I'm talking about? Thanks

Yes, the Thruwall Locator does exactly that, £37.95 from Mills
(www.millsltd.com) part no C00-7951.

You use Blu-tak to stick the transmitter to the point where you intend to
drill and move the locator up and down and sideways on the other side to
pin-point where the drill will come out. Of course you'll still need a cable
and pipe detector to make sure there's no surpises in store before you
drill.