On Sun, 06 Nov 2011 21:25:10 +0000 (GMT), "Dave Liquorice"
wrote:

with the tool you know it has been set
correctly not partially set or over done.

How does the tool "know" the bolt has been pulled as far as it can?
After all, you can get these in different lengths, so surely it would
have to pull longer bolts further to fully set them?

I can see that if it was under done, the "petals" would not have
opened fully, so would distribute the weight over a smaller area. What
is the problem of over doing it? Is it that it starts to draw the
fixing into the plasterboard, enlarging the hole?

To use the tool, do you pull the "trigger" once or do you have to pump
it a couple of times?

As for load bearing, they spread it over quite and area behind the
board and most loads are sheer. Must admit I'd be wary about fixing a
wash basin with them but that's more down to the plasterboard
deforming over time rather than a failure of the fixing.

I am surprised you can fit radiators with them, I hadn't realised
plasterboard was so strong. I had visions of the fitting being pulled
through the plasterboard and the plasterboard, rather than the fixing,
breaking.