Mailboat Letters

Fire Away

The very first sentence of "Fire Away" in the October issue of Seaworthy seemed to contradict my long-understood concept of combustion; i.e., that there are three necessities: fuel, ignition, and oxygen. Somehow, the last of these was left out of the article. Perhaps it was obvious that oxygen (in air) is around and in boats, but it is required for combustion. As an aside, spontaneous combustion can occur without an obvious source of ignition; I once had such an experience. I sat on a fuel-soaked timber while working on the bottom of my boat, went home, took off my stained pants, showered and returned to see my pants smoldering on the floor. After taking them outdoors, they burned!



Editor: You are, of course, correct that oxygen is needed for combustion, and that many fire-suppression systems work by depriving the fire of oxygen. As you surmised, we focused on the ignition source and the fuel source as being the two ingredients that are normally missing, while oxygen is, except in very rare cases, not the inhibiting factor on a boat.

We do sometimes see cases of spontaneous combustion on boats. In that case, we could argue that the ignition source was the heat required to bring the combustible material to ignition temperature. Without that, spontaneous combustion would not occur, no matter how much fuel and oxygen you have.

 

In the 2nd to last paragraph of "DC Electrical Fires" it is stated, "... batteries were hooked up in parallel instead of in series." If you are dealing with 12V batteries and you hook them in parallel you will remain at 12VDC, but you will have as much amperage that both batteries can produce. This is perfectly fine with the exception of isolation charging. If you hook two or more 12V batteries in series you will create 24+ volts! Doing so will cause smoke to escape from your electronics and could start a fire.



Editor: Several readers caught our mistake. You're right; we got it backwards. Hooking batteries up in series instead of parallel will create more voltage and can lead to a fire.

Lubricants Roundup

I always enjoy your articles, and you always have good new information. Question about lubricants to slow down rust: I have hose clamps in the bilge which look to have a light rust buildup that I wanted to treat. I understand that some treatments could hurt the rubber hoses that they are holding. Comments about where you should not use these lubricants?



John Tiger writes: You can simply use good ol' WD-40 to protect these clamps and slow down rust. According to their website, WD-40 is designed for use on rubber surfaces so it will not harm or degrade your rubber hoses. Furthermore, WD-40 now has "WD-40 Specialist" products available, designed for specific functions, one of which, called Long-Term Corrosion Inhibitor, is specifically formulated to prevent rust and corrosion. I'd give that a try. Lastly, ensure that those hose clamps are of good-quality stainless steel. Many are not, and they'll degrade prematurely in a wet environment.

 

The author recommends Never Seez for wheel lug nuts and other similar fasteners. While anti-seize compounds are great, some fasteners are required to be torqued to a specification dry.  I learned this the hard way after snapping several lug bolts on a vehicle and discovering that the manufacturer specified the torque for the lug nuts dry. I thought I had bad lug bolts, but the anti-seize compound made the reading on the torque wrench much lower than it actually was. Moral of the story is to check the manufacturer's specifications and realize that you may be applying a lot more torque to a fastener using anti-seize compounds.



Water Heater Alert

In the October 2015 issue of Seaworthy you pass off water heater maintenance with a shrug, " ... after all, there are no moving parts." Wrong! You comment on the closed valve on the pressure-relief line, but totally ignore the pressure-relief valve itself: a moving part. That item should be cycled at least annually to assure it is functional and not jammed with scale. Then there is the gas valve: also a functioning, moving part. Or if the heater is electrical, there is a switch and its associated heavy wiring. So, please go back and give the water heater its due. There are a lot of moving parts, wiring, and piping associated with a water heater that need to be tended to.



Wake Up!

After reading your article "Watch Your Wake" (October 2015), I have a question. I have a second home on a lake that is long, but not very wide. There are many other homes on this lake, and we all have water toys — boats, canoes, paddleboards, etc. During the warm months, especially on the weekends, most of these homes are occupied, and everybody wants to use all of their toys. Now, a couple of relatively new activities have become popular — wakeboarding and wakesurfing. These activities create large wakes that usually reach both sides of the lake, splashing water onto docks and shorelines. Now the question: Should any damage be inflected by these wakes, can a lawsuit be brought about, and what would be needed to do so?



Raul Chacón responds: The short answer is that yes, a lawsuit can be filed, but the difficulty may lie in identifying the culprit. With that many boaters, a potential defense could be that it was not their wake, but that of someone else. Wakes may also be amplified when in synch with other wakes, thus the possibility for multiple parties at fault. Hopefully, a friendly discussion with the operator can preclude the need for legal action.

 

We enjoy the timely articles in every issue of Seaworthy. We usually read the whole publication the same day that we receive it. Regarding the article in the October issue, "Watch Your Wake!," we would like to share something that seems to work for us. Instead of yelling over the VHF at the bozo who passes too close and too fast, we calmly say something like this: "Securite, Securite, Securite. This is Dharma. This is a warning to all vessels transiting between Dodd Narrows and Nanaimo. The 45-foot Bayliner Rocket Ship is traveling northbound at a high rate of speed creating a very dangerous wake as it passes close by other vessels. Vessels between Dodd Narrows and Nanaimo should be on the lookout for the substantial wake that Rocket Ship is creating." If we can't read the name we just give a good description. In our experience, the vessel usually slows down.



 

To the gentleman who wrote the wake article, a big thank you. I built a 28-foot trawler tug that is quick to roll. The summers here in Puget Sound, Washington, are busy with boats of all descriptions; the worst are those with huge stern wakes. They seem to go from point A to point B with no regard for who or what is around them. I may make copies of your article to hand to them if I see them in the same harbor.



More Marine Corrosion 101

I enjoyed your excellent article on corrosion by Ed Sherman in the July issue. The availability and use of aluminum for cathodic protection has been very slow in coming. We live on our boat for four or five months in the upper Chesapeake Bay (very low salinity) and the rest of the time on the East Coast and in tropical Atlantic waters. While in the Chesapeake, I have noticed a hard coating buildup on my zinc fish, and I am considering shifting to an aluminum fish. In addition to the fish, I currently have zinc anodes on my rudder strut and propeller shaft as well as in my engine and generator. Would using an aluminum fish concurrently with my installed zincs anodes have a detrimental effect on the boat's cathodic protection, or would the zinc just try to protect the aluminum fish? Should all anodes be changed when moving from saltwater to fresh/brackish water for an extended period of time?



Ed Sherman responds: Based on what you have told me, you will be best off using the aluminum anodes exclusively, though it is a bit of a challenge in some cases to find aluminum anodes for specific purposes. But it should be your goal to switch to aluminum for everything as you can. You won't harm your cathodic protection system per se by having a blend of zinc and aluminum anodes. But you will be "confusing the system," for lack of a better phrase. Why? Because the effective potentials of the materials are different, and therefore they will sacrifice at different rates. The zinc, in fact, may simply coat over in the brackish/freshwater environment. Once they pacify, their ability to even function as a sacrificial anode is typically gone without roughing up the surface to get new zinc exposed. Aluminum functions well in both brackish and saltwater. 

— Published: January 2016

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