Steve Tuckwell Manager, Water Regulations
Advisory Scheme raises concerns regarding the illegal use of
lead solder and the improper use of fluxes. Reported in PHAM
News May 2001.
I have not trained as a plumber and it is with
some hesitation that I am writing about the skills which should
be second nature to all plumbers. But recent experience shows
that some plumbing work leaves much to be desired. The illegal
use of lead solder and the improper use of flux are causing
concerns about health risks amongst water suppliers, plumbing
associations, water fit- tings manufacturers and health authorities.
Reasons for concern
In the past eighteen months, a young boy and his father,
who had both been unwell for some time but without any clear
causes, went to see their doctor, who recognised the signs
of lead poisoning. Blood tests confirmed the diagnosis and
detective work showed it was due to drinking water with excessive
amounts of lead in it. The lead came from lead-based solder
used in jointing the pipework.
The child was in the habit of taking a glass of
water for night time drinking from a little-used tap in an upstairs
bathroom. The father drank a lot of water at home and took hot
and cold drinks to work with him. They didn't live in an old
house which might have been built with lead plumbing. Their
home was recently built - built since the 1987 water supply!
byelaws outlawed the use of lead] based solders for hot and
cold water systems. A follow-up survey revealed over 15% of
houses up to three years old had illegal use of lead solder.
This was not limited to one estate, one builder or one plumbing
Ban on use of lead solder
response to concerns about health effects of even low levels
of lead in drinking water, since the 1980s lead based solder
has been outlawed for use on' hot and cold water systems.
Leaded solders can be used for non- drinking water systems
such as closed circuit central heating pipework, where the
water is not required to be wholesome. These requirements
have been incorporated into the new Water Fittings Regulations
(Water Byelaws 2000 in Scotland). Water Suppliers have the
duty to enforce these regulations. Where the illegal use of
lead-based solder is found in drinking water systems, the
Water Supplier is likely to require all the joints to be remade
at the installer's cost. The installer could also face a criminal
charge and a fine.
Alternatives to lead solder
and press-fit fittings are alternatives to soldered joints.
But where soldered joints are required or preferred, lead
free solders are available either in integral solder ring
fittings or for end-feed use. The use of a solder such as
number 23 tin/copper alloy soft solder, made to EN 29453,
will ensure that lead levels are not a problem. Not only is
it suitable for all soldering work, but because it is less
dense than lead solder, there's more on a 500gm reel, giving
more joints per reel.
Fluxes -good and bad
Flux helps molten
solder to wet, adhere to and alloy with the copper tube. The
change to lead- free solders with their higher melting points
than the lead-based solder requires the use of an appropriate
flux. For ordinary soft solder joints, fluxes made from zinc
chloride or zinc ammonium chloride are usual. The manufacturers'
advice should be followed. Modern fluxes, especially the self-
cleaning types, can be more aggressive to the copper tube
and need to be used with extreme care. Excess use of flux
causes increased rates of corrosion of the pipework. There
are examples where very high levels of copper and lead have
occurred in water left in contact with poorly made joints
suffering from excess flux residues. Ultimately, excessive
corrosion can lead to premature failure of the pipework and
Cleaning and fluxing
deburring a cut tube end inside and out, the outside of the
tube should be cleaned, with the green abrasive impregnated
nylon kitchen scouring pad recommended for domestic use to
avoid steel wool fragments in the system. Flux should NOT
be applied to the fittings, but immediately after cleaning
a thin coating should be applied to the outside of the tube
only. Assemble immediately to avoid contamination by dirt
or dust and distribute the flux internally by twisting the
fitting onto the tube. Wipe off any excess flux. Heating the
tube and fitting should be even and only hot enough to melt
the solder. Hotter than this risks charring the flux. For
integral fittings, gentle even heating until a complete ring
of solder appears at the mouth of the fitting is sufficient.
Resist the temptation to end feed additional solder to an
integral ring fitting. For end feed joints, the tube and fitting
should be heated sufficiently so that, with the heat source
removed, the solder melts and flows into the joint when touched
onto the tube. Avoid using too much solder; for small tube
joints using solder wire, a length equal to the tube diameter
should be sufficient to fill the joint.
After the joint has cooled, residual flux should be cleaned
from the outside with warm water. The pipeline should be flushed
to remove flux residues and any debris, using cold water for
water based fluxes, but hot water is better for grease-based
fluxes which may not be removed by cold water flushing.
recent leaflet on Fluxes and Solders, published by the UK Copper
Board, sets out the proper advice and precautions to follow.
Further information is available from their website: www:
Water Regulations Advisory Scheme (WRAS) offers a free advisory
service on matters relating to the Water Fittings Regulations,
but for local matters please contact your local Water Supplier.
can be contacted by telephone, e-mail or letter:
The Water Regulations Advisory Scheme
Pen- y-Fan Industrial Estate
Tel: 01495 248454