NPT, NPS, LOL, SOS. Alphabet soup again? Kind of like going to the plumbing department at the Tru-Value hardware store or West Marine. Buy one of everything and hope you got the right parts that fit from A to B. Just getting things connected from A to B may not be correct or safe. Our thru-hull fittings all have NPS (National Pipe Straight) threads, always have. These threads allowed us to use a hacksaw to cut the fitting to the desired length and thread a flanged "seacock" with NPS threads down tight to a fairing block and secure the flange to the hull or fairing block. The inboard end of that seacock will have NPT (National Pipe Tapered) threads allowing the use of standard NPT plumbing fittings. Now those inline ball valves, which are considerably less expensive than seacocks, and have NPT threads that are not compatible with our NPS thru-hull fittings, but we keep putting them on those thru-hull fittings. Well that mis-match of threads will not meet ABYC standards (See ABYC H-27; Seacocks, Thru-Hulls and Drain Fittings for details) for below the waterline thru-hull installation. See the attached photo showing inadequate thread engagement for mismatched threads. A flanged adapter is available from Groco to get you from those NPS thru-hulls to NPT inline valves and bronze pipe fittings. In a future post we will explain bronze vs brass and why not to use brass in raw water applications below the waterline.
Please feel free to email me if you have questions on this topic or others.
One of the most annoying things onboard is to jump in the bunk after a long day going to weather and find the cushions cold and wet, or pulling that book from the shelf and finding it moldy. Investigating the source of the wet can be frustrating. After finding the ports, windows and hatches all secure, then what? What about all that hardware and deck fittings fastened through the deck. Those grab rails we have been pulling on, the cleats handling the stress of dock lines, not to forget the hardware for handling those sail control lines. All those stresses year after year tends to break the bond of the bedding compound, yes even 5200. Removal and re-bedding of all deck fittings should be a maintenance item to be considered after about ten or so years, better yet to do a few items every year or two as it can be a big job. The consequences of not doing it can be costly if it leads to soft decks needing to be re-cored. So the wet bunk and moldy book should definitely get your attention as more than a nuisance. The effect of water intrusion on chainplates will be discussed at a later date.
From ABYC E-11;
E-11.10 OVERCURRENT PROTECTION
11.10.1 LOCATION OF OVERCURRENT PROTECTION (For) DC CIRCUITS
126.96.36.199 General Requirements
188.8.131.52.1 Overcurrent Protection Device Location - Ungrounded conductors shall be provided with overcurrent protection within a distance of seven inches of the point at which the conductor is connected to the source of power measured along the conductor.
1. Cranking motor conductors.
2. If the conductor is connected directly to the battery terminal and is contained throughout its entire distance in a sheath or enclosure such as a conduit, junction box, control box or enclosed panel, the overcurrent protection shall be placed as close as practicable to the battery, but not to exceed 72 inches.
3. If the conductor is connected to a source of power other than a battery terminal and is contained throughout its entire distance in a sheath or enclosure such as a conduit, junction box, control box or enclosed panel, the overcurrent protection shall be placed as close as practicable to the point of connection to the source of power, but not to exceed 40 inches.
4. Overcurrent protection is not required in conductors from self-limiting alternators with integral regulators if the conductor is less than 40 inches, is connected to a source of power other than the battery, and is contained throughout its entire distance in a sheath or enclosure.
5. Pigtails less than 7 inches in length are exempt from overcurrent protection requirements. ..............
What's the big deal? For one thing it is no longer just a recommended ABYC standard, it is the law. Federal Code of Regulations; 33 CFR 183.455 pretty closely states word for word the above recommendation. The purpose of these regulations and standards is to prevent the loss of life and property due to onboard fires. A short circuit in a DC circuit should trip an overcurrent device, not use the wire or an electrical device as a fuse and "let the smoke out" in the form of flames.
So if nothing else it is a good idea. Questions feel free to call or email.
Accurate photos or glamour shots? In the course of my job poking around boats, I often hear from my clients "the boat does not look like the brokers photos". As a buyer you need to remember the brokers photographs are sales literature, meant to show this is the boat of your dreams. I do not often see photos that I believe are meant to deceive, just to show a buyer the boat is worth a visit. If you are not enticed to look, you may miss out on the boat of your dreams. So, ask if the photos are current, ask for close ups of areas of interest. Often the boat is not local to a potential buyer. As a buyer you can seek a surveyor local to the boat to have a look for you and give you feedback on its general condition. After all, the boat may just be the boat of your dreams. Or, for two or three hours labor cost the surveyor may save you a lot of travel time and expense, not to mention the aggravation and first hand disappointment of seeing a boat suffering from years of deferred maintenance not depicted in the photos.
Often, in the fall during the process of a survey here in eastern North Carolina, clients will ask about the need to winterize a boat in this part of the world. Many are transplants from the cold northland like myself thinking of those lower 50° average daytime temperatures in January. Well the water temperatures may not often go below 40° and even skim ice rare, but below freezing temperatures are not that rare. Every year since our relocation to east central North Carolina I have seen temperatures drop below 20° every winter. Two nights down to 16° in a row and a daytime high of 30° and the potential for freeze damage is real. And every spring I have been onboard boats that have had freeze damage. While burst freeze damage to major engine components is not common, damage caused by raw water system freeze damage can be serious due to flooding. Fresh water system damage due to burst components may not be as catastrophic, but it can be messy. Do yourself a favor, anti-freeze is cheap insurance, winterize all your fresh and raw water systems onboard yourself or hire a contractor, you will sleep better and have a better spring. I give this advice to everyone down to the Georgia-Florida line.
One of the things that conjures up more fear than drowning while boating is a fire onboard. There is just cause for this due to the confined space of a boat, the likely hood of explosive products on board and the limited options for escape. Now it seems that one of the two essential items we keep onboard as required by law for safety's sake may be being recalled. Kidde, one the leading manufacturers of fire fighting equipment is recalling 40 million fire extinguishers dating back to the 1970's, many of which will be found on our boats. Many vessels I have surveyed recently have had one or more of these recalled fire extinguishers onboard. The easiest way to determine if you may have one onboard is to check the handle, the recalled ones have plastic handles. Take time to check the link below to see if your fire extinguishers have been recalled. Many will be branded by names other than Kidde. Remember, a working fire extinguisher and the know how to use it can be the difference between an inconvenience and a disaster onboard.