The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1916-12-21
Prevention of Misfires--Some Practical
Suggestions of Subject of Importance
tE p. Brooks in Mining and Scientific Pressl


using fine rock. for the reason that the
side splitting of the fire in the fuse
win sometimes set fire TO the powder,
which, while it does not explode, will
generate sufficient gas to force the
tamping out of the hole, drawing the
fuse with it and leaving another miss
ed hole. Had there been no tamping
used, even if the powder took fire and
burned faster than the train of powder
in the fuse, it would explode the
charge as soon as the fire reached the
cap.
| would suggest that in holes point
ed downward, a handful or two of fine
dirt be thrown into the hole, but not
firmly tamped, using this as a safe
guard against accidents when firing or
splitting the holes, such as the acct
dental dropping of lighted candle
into the hole or dropping the lighted
end of a fuse into it.
Many times report short or misfires
are traeeable to carelessness or to the
nervousness, due t. mexperience of
the man splitting the round of holes,
In his haste to leave the miner over
looks some of the fuses and so fails
to spit them. Evidence of this is not
Iinfrequently found in the broken rock
"a fuse with cap attached-which,
upon examination, shows that it never
had been lighted, A fuse cut to pro-
fper length will give the miner abund-
amt time to reach place of safety
In blasting under water or in wet
ground it is absolutely necessary to
see that the point Of union between
fuse and cap is waterproof This may
be accomplished with a good pair of
crimpers, properly used, without the
use of any waterproof substance such
as axle grease which is SO commonly
used for this purpose. However, 1t Is
generally safer to employ some kind
of waterproof substance. But axle
grease or anything containing coal oil
is not recommended, for, II left too
long it will penetrate the fuse, and
possibly cause a misfire. There Is on
the market and handled by most the
dealers in powder a preparation made
for this purpose that is more reliable
than most kinds of grease or wax.
The kind of crimpers used is large
lily a matter of preference. | prefer
those making a groove around the
leap. Make a double crimp, turning
the fuse slightly after making the first
crimp, and take care to crimp close to
the joint between the fuse and cap,
cap for if crimped too close to the
illuminate the flash from the little
powder remaining in the fuse between
the crimp and illuminate may not be
strong enough to explode it, while II
one-half inch or SO of fuse is left be-
low the crimp, the force will be suffi-
cient even if tightly crimped, Care
should be taken to see that the dia-
meter of the fuse is just slightly
smaller than the shell of the cap, fol
if too tight, the crimper will com.
press the fuse so tightly that the fire
may fail to pass the point of com.
preston, when there is created an
other cause for a misfire. By observ
ing the foregoing suggestions, will
ordinary care the miner will reduc
to- a minimum the chance of having
missed holes and instead of being tn
rule they will become the exception
Above all things do not use the teet
for a crimper.