In article <29bagv89i2ue6m0m3e03ep1jhv24qgg8q8@4ax.com>,
   Gnube <donotspam@dsl.pipex.com> wrote:
> >I always start with hammer off. If you hit mortar (particularly
> >lime mortar) with SDS hammer on, you end up with a hole 3 times
> >broader and 10 times deeper than you intended in less than a
> >millisecond ;-)
> >
> >Also, I've had the occasional soft brick which drills fine without
> >hammer, but shatters to a thousand pieces if an SDS hammer drill
> >bit touches it.

> Actually, you've just made me wonder if on buying an SDS, might it be
> better off using the old hammer first, and switch to SDS when the
> going gets too tough for it. The thought I'm having is that you'd get
> it started gentler and possibly more accurate based on your comment
> above, and presumably conserve the life of both tools a little better
> too. Granted it'd be a bit more messing about to do it though.

An SDS drill won't engage the 'hammer' action without pressure. So if
you're unsure how hard the masonry is, start with gentle pressure. If the
drill goes in as it will in soft material it won't damage anything.

-- 
*I used up all my sick days so I called in dead

    Dave Plowman     dave.sound@argonet.co.uk     London SW 12
     RIP Acorn