LEAD WOOL
Lead
wool is made by scratching fine strands from the surface of a
Lead disc. It is used for the caulking of joints in large pipes
e.g. gas mains and in some specialist batteries.
Lead Wool, a form of caulking Lead, is long, fine strands of
chemical grade Lead which is twisted into 5/8”rope for use in
various applications and is available in 5 lb. cartons or 50 lb.
waterproof bags. It averages about 2-½ ft. to one pound. Lead
wool is certified to meet Federal Specification QQ-C-40.
The Lead wool is used to seal flanged connections, cast iron,
cement and earthenware pipes, and apertures of walls and
ceilings. Very good ductility of Lead ensures fast and easy
filling and sealing of small slots too. It is also convenient
for anti-radiation protection. The Lead resistance to aggressive
environment is a warranty of long-term durability of seal.
Lead wool, a loose rope of fibers, is produced by passing molten
Lead through a fine sieve and allowing it to solidify. When
forced into a crevice under considerable force, the fibrous rope
cold welds into a homogeneous mass, forming a solid metal seal.
This caulking process is useful where temperature or explosion
hazards prohibit the use of flame heating. The gaps between Lead
shielding sheets in nuclear submarines are often filled and
caulked with Lead wool. It is more convenient to use than molten
Lead for caulking purposes because it requires no heating or
pouring. Lead Wool properly packed is ideal for caulking and
makes a tighter seal than molten Lead which shrinks slightly
after casting.
Element |
Grade AA |
Grade C |
Grade D |
(Max.) |
(Max.) |
(Max.) or range |
Lead |
1 |
1 |
1 |
99.7 |
99.7 |
99.82 |
Antimony and arsenic (total) |
2 |
2 |
0.002 |
0.02 |
0.02 |
Iron |
- |
- |
.002 |
Bismuth |
- |
- |
.025 |
Zinc |
- |
- |
.001 |
Copper |
- |
- |
.040 to 0.080 |
Silver |
- |
- |
.020 |
Tellurium |
- |
- |
.035 to .055 |
Tin |
- |
- |
.016 |
1 Minimum. |
2 Antimony content only. |
Lead Wool is twisted loosely into rope form. It is easy to
use than molten Lead for caulking purposes because it does
not require heating. In some situations, wet conditions, for
instance, are hazardous to use molten Lead to make caulked
joints on cast iron drain pipe. In such a situation the
solution could be to use the process of Cold- Caulking by
making a caulked joint with Lead wool. Very good ductility
of Lead ensures fast and easy filling and sealing of small
slots too. The Lead resistance to aggressive environment is
a warranty of long-term durability of seal.
It is ideal for filling openings where sheet, plate, or
brick are not suitable and is positively the best way to
fill crevices.
Applications / Uses
- Lead Wool is used to seal flanged connections, cast iron, cement and
earthenware pipes, and apertures of walls and ceilings.
- Lead Wool is also convenient for anti-radiation protection.
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