Knock Knock Page 2
Q & A — July 2002
By Capt. Ken Kreisler
| Part 2: Charging Voltage, Epoxy Failre, and more
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
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.
does the charging voltage of a battery mean? J.A., via e-mail
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.
could have caused the bond on my epoxy job to fail? G.T., via e-mail
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.
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: firstname.lastname@example.org.
No phone calls, please.
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.