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The
flow on my pressurized water system has dropped to less than half of normal.
How should I troubleshoot this problem? C.S., via e-mail
First check
the electrical components, including the pump itself, wiring, switches,
and the pressure sensor. Look for any corrosion buildup or loose or burned
wires. If everything seems fine, try to localize the problem, checking
to see if it’s on a particular line or on just the hot or cold water
side. Once you determine this, look for a restriction in that water line,
perhaps a kink or a place where something is lying on a hose. Also check
for a leak by looking for water accumulation, being mindful that water
can run some distance before it’s visible.
The
water filter is a frequently overlooked trouble spot. It may not be tightly
affixed, or its gaskets may be leaking. If it’s clogged, you may
observe spitting or hear rattling when the tap is turned on. Finally,
check the mesh screen in the faucet end, which can become blocked by corrosion
or mineral deposits.
What
does the charging voltage of a battery mean? J.A., via e-mail
The battery
charging voltage is the voltage measured across the battery terminals
during charging. It consists of the battery voltage plus the voltage drop
due to the internal resistance of the battery; the battery’s internal
resistance opposes the charging voltage, so the voltage produced by the
charging unit must always be higher than the battery voltage when the
battery is being charged.
The
on-charge voltage is affected by temperature, electrolyte concentration,
plate area in contact with the electrolyte, age of the battery, impurities
in the electrolyte, and the state of charge and gassing.
Gassing,
consisting of hydrogen produced at the negative plates and oxygen at the
positive plates, temporarily increases the battery’s internal resistance
because of the gas film formed on the surface of the plates. Plates with
hard and crystalline sulfate deposits also cause the internal resistance
of the battery to increase.
What
could have caused the bond on my epoxy job to fail? G.T., via e-mail
There are
several possibilities. The first is insufficient cure time. Check with
your manufacturer for correct cure times and mix ratios. The second is
that resin-starved joint epoxy has wicked into a porous bonding surface.
You’ll have to clean things up by sanding and wetting out the bonding
surfaces before applying the thickened epoxy. Make sure to re-wet very
porous surfaces, especially end grain wood.
You
could also have had a contaminated bonding surface, or the bonding area
may have been too small for the load on the joint. Resanding and cleaning
will help. For a too-small bonding area, consider using fillets, bonded
fasteners, or, depending on your skill level, scarf joints. Finally, if
you applied too much pressure during clamping, this could have caused
the epoxy to be squeezed out of the joint.
Need
help with a maintenance problem? Write to Maintenance Q & A, Power
& Motoryacht, 260 Madison Ave., 8th Fl., New York, NY 10016. Fax:
(917) 256-2282. e-mail: ken_kreisler@primediamags.com.
No phone calls, please.
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