An increasing number of people are replacing old and rusted 3/8"
Rawl
5-piece bolts (aka 6-piece bolts; longer bolts have one more sleeve
piece).
Expansion of the old hole to 1/2" is common, although the 3/8"
hole can
sometimes be reused without any drilling (even good granite can
be weakened by the long-term interaction of the rust with the rock).
The procedure is pretty simple, but getting the sleeves out can
be a pain
(especially if they are seriously rusted).
Basic Removal Procedure:
Unscrew the old bolt.
Take out any sleeve pieces that come out easily.
Blow out the hole.
Screw the bolt (just the bolt, no hanger or washer) in a couple
turns.
Tap the bolt in with one hard tap. (this unseats the cone from
the sleeve)
Unscrew the bolt.
Pull the sleeve via one of these methods:
a) If you're lucky, you can grab the sleeve top with a needle-nose
and just
pull it out. (only on shallowly installed short bolts)
b) Use a hook of some sort to pull the sleeve out - I used
to use a heavy copper wire for a hook.
c) Use a nail or drift pin and pound it in along the seam
in the sleeve; (you
have to be able to spot the seam) this "rolls" one side
in a bit, you may
need to do it a couple times, then pull out with needlenose pliers.
Don't
pound the nail in too far, you don't want to damage the threads
of the cone.
d) IF VERY RUSTED: use a nail or drift pin to break up the
sleeve, then
pliers or a hook to pull them out.
Once the sleeve is pulled:
Blow out the hole.
Screw the bolt, plus a beater hanger (without the washer), 2-3
turns into
the cone.
Funk the cone out - it will come out easily unless severely
rusted, but
if it's that rusted it will disintegrate. (If you don't have a
funkness
device, they're widely available; all they are is a 2-3' wire
cable with
loops at each end, called various things by various companies.)
Blow the hole out, check for debris, and you're all ready to
go.
Inspect:
Of course, always inspect the old hole & the rock; sometimes there's
too
much damage to safely re-use the hole, but usually this only happens
in very
soft rock.
Special gear required:
A hook (made out of heavy wire or even a thin coathanger)
Needlenose pliers
Funkness device
Drift-pin or nail
|
