Friday, June 23, 2017

Cutts and Case

The mid-Atlantic pinnacle of classic wood boat repair must be Cutts and Case of Oxford, MD, at least judging by what I see in the show room, yard and slips. Some of the boats come here for restorations, some come every year for touch-ups and TLC.


Perfect varnish so deep you can measure it with a ruler.


This 80-year old folk boat is a perfect example of preservation and continuous care. Wonderful to behold, but I'm sure glad I don't have to keep after it. A labor of love.

No plastic classics or race boats here, though I have seen a classic riveted aluminum runabout that was gorgeous in its own way.

A must-see if you are in Oxford, MD. Visit the shed by land, and then the docks by dinghy... after getting ice cream at the Scottish Highland Creamery, of course. The creamery is a just a hole in the wall, by outward impressions, but I've seen them bring tourists by the bus load.


Major work.

The best place to park your dinghy is at a small public park near the end of the strand, on the town creek side. There is a tiny beach and a tiny pier.

Friday, June 16, 2017

100 Best Buys--Chapter 5

This will be a weekly feature for the next five months. I figure a goal will keep the pressure on.

I think of this as an adjunct to my book "Keeping a Cruising Book for Peanuts," although certainly there is some overlap. I've tested a lot of stuff. Many of these items were mentioned in some prior post--use the search function to find more information.

While you're at it, subscribe to Practical Sailor Magazine. The product descriptions are better, there are comparisons and options, and the test methods are explained. They research stuff I avoid, like electronics. One good find--or bad purchase avoided--and it'll be the smartest $39.94 you'll ever spend.



Holding Tanks

Oh that smell. The hoses permeate, stink coming through the walls. The stuff in the tank is indescribably, and whenever someone flushes we know. And when you go to pump it out it's slow going. Or rather that is the way it used to be, until I made a long (ugly) study of this for a series of articles and for my own sake. Now all is peaceful and sweet-smell. Well, darn close.

21. Hoses. A holding tank hose should be be odor-proof, easy to bend, easy to clean, and inexpensive. Unfortunately, you can only have two of these, and odor-proof is obligatory, a least in my recommendations. That rules out all "white" hoses and all standard water or exhaust hoses.

My recommendations? I actually have had all of these (and some others) installed on my boat for at least five years, or I would not recommend them. I'm sure they will last 10 years +.
  • Trident 101 (black) or 102 (white). Stiff, but rugged as hell. Probably the best value, if you can make it fit. It is NOT as stiff as the dreaded white hose. Get black, because the white is hard to clean.
  • Raititan Saniflex. The most flexible hose available, this will go places no other hose will. A good reputation for resisting permeation, and perfect for the DIY.
  • Shields Poly X. With a lifetime warranty and the easiest cleaning, this is a best... but there is a steep price. Still, it is a nasty job, so I think it is worth it.
  • For vent lines (3/4-inch to 1-inch) you will have to use Shields 140 "white" hose. These upgraded hoses are not available in smaller sizes. Do not use any other hose for vents--clear vinyl permeates within weeks.

Tips: A few simple trick can make fitting hoses simpler:
  • Always flush will lots of water before you start. A vinegar flush with some soak time also helps.
  • Work in warm conditions. All hoses become stiff in cool weather. If you must work in the winter, warm the hoses and heat the work area to sauna-temperatures.
  • Lube with K-Y (no wise cracks). It was invented as a surgical lube, with the requirements that it wash away easily and not damage any rubber type. Lubing with grease can damage the hose and reduce sealing security. Glycerine is also good.
  • Never use a sealant on the hose barb. It will leak and you won't be able to fix it. If you need a sealant there is something wrong with the fit or the barb.
  • A radiator hose pick is handy when it is time to remove the hoses.
  • Add a 90 bend if the hose can't make the turn--it is better than forcing it and making a kink. In fact, there is no reason you can't use PVC pipe for large parts of the run, so long as there is flexibility at both ends.
  • Standard American hose barbs don't fit sanitation hose--head vendors sell smooth (not barbed) fittings for sanitation hose. Double clamp (screws on opposing sides) and never use them for a pressure application. 
  • Soak the hose ends in boiling water if they don't fit. It really helps and it works better than a hair drier. But do be careful not to spill it on your lap.

 Left to Right: Jabsco, Groco, and Rairitan. The Groco valve is cheap, but it is stiff and is not recommended. Funny, that they are all the same basic size.

22.  Raititan PHII Joker Valve. I bet you have a Jabsco manual head. Most people do. after a year, water starts to seep back into the bowl, even if you flushed enough water and pumped enough dry strokes. Well, the Rairitan PHII joker valve is interchangable with the Jabsco valve and lasts 2-3 times longer. The cost is greater, but measured in $/year it is cheaper, and the labor savings is material.

23. Chemicals. Practical Sailor did a bunch of testing of chemicals, and those based on either Nitrate or enzymes generally worked very well. They work by supplying oxygen in an alternate form (nitrate) so that the bugs do not have to use sulfate and make bad smells. Forespar Refresh was a favorite, along with Odorlos and No-flex. My favorite is Camco TST Ultra Concentrate Singles. What does not work is the nasty traditional blue stuff. At least  one brand still contains formaldehyde, a known carcinogen. It also does not work nearly as well.

Camco TST Ultra as a spray keep the bowl fresh and clean.


My favorite trick is to use it as a bowl spray, rather than to dump it in all at once. I dilute it about 4:1 in a small spray bottle, and then spray the bowl liberally with a few pumps after use. In addition to clearing the air, it treats the waste in the hose, something a one-time dose in the tank will never do.

24. Vent Filters. Actually, I would rather see you solve odor problems in more basic ways. Stink (hydrogen sulfide and other mercaptans) result from waste being digested under anaerobic conditions. Just add a little air and the bugs will make carbon dioxide instead. The air does not need to penetrate to the bottom, because the bugs near the top will eat some of the stink burbling up if they have enough oxygen to work with. But then why did they make sulfide (S -) and from what? They made it from sulfate (SO4 2+) because lacking air, they needed a source of oxygen. The sulfate came both from the waste, but more so, from the seawater we often flush with. So if we shorten the vent, increase the size to at least 3/4-inch, and flush with fresh water, that will all help. The above mentioned nitrate (NO3 +) will also provide oxygen. Finally, we try to locate the vent away from air intakes. My problem was that the vent was right under a salon air intake. It would have been easier to move it, I suppose.

 The Big Orange OEM is refillable and has a built-in vacuum break. The original Big Orange is a monster, suitable for live aboards and multi-head tanks.


If you can't fix the problem and move the line, there is always a vent filter, which I have explained in depth. I recommend one (Big Orange makes some nice ones), but I would rather you made your own.

25. Pumpout Procedures. The biggest goofs are not flushing enough water in a misguided attempt to stretch holding tank capacity (makes the waste too thick and shortens hose life) and flushing anything other than waste and single-ply tissue. Even Kleenex can be fatal (if it can survive the laundry in your pocket it certainly is not going to dissolve in the holding tank). However, the third most common goof is not removing the entire length of the pump out hose from the hook and laying it flat on the dock. Every time the liquid must rise up a loop, that increases the suction lift, and if there are four loops left on the pump stand, that's an extra 12 feet of lift. Adding viscous drag and the lift from the bilge, that's more than the pump can do, and pumping will be slow or unsuccessful. Lay the entire hose on the dock.

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Finally, do NOT use vegetable oil to lube the head. It seems like it works, but it causes the waste to clump-up, causing pump-out problems in the future. I did a lot of testing for magazine articles, and adding oil was the only thing that correlated with sludge build-up. Makes sense. This is the reason it is illegal to discharge cooking oil into the sewer, except instead of a legal penalty, you will simply have a tank full of sludge. That's pretty real.

    Saturday, June 10, 2017

    Holding Tank Vent Filters--Why Carbon Lasts Much Longer Than Laboratory Testing Suggests



    Warning: Reading this article may cause a mild ice cream headache in non-chemists.

    The primary interaction of carbon with organic vapors is surface absorption, and the published Dometic tests explore this. The test method they used uses only hydrogen sulfide plus nitrogen at steady flow and is designed to measure only adsorption capacity. However, carbon presents a very complex surface and presents very complex behaviors. In the presence of fresh air we have catalytic removal of sulfur by this simplified mechanism:

    1/2O2 + H2S ---> S +2H2O
    While this reaction eventually fouls the carbon--I have observed sulfur crystals fouling the inlet side of my vent filter after several years--it does extend its life by many times. The carbon bed must be sufficient in size, as this is a slow reaction in most activated carbons, and oxygen is only available in small amounts, provided by thermal in-breathing of the tank, inflow during pump outs, and slow bidirectional flow in the vent hose. The oxygen requirement is easily met, however, as it is many times less than that required to support aerobic tank conditions. Again, the standard ASTM method used by Dometic is not appropriate for estimating carbon life when catalytic reactions are present, because the method substitutes nitrogen for air, eliminating oxygen from the process.

    Additionally, the carbon does not need to remove sulfide—or any other odor, for that matter—on a continuous flow basis to attain odor control; it need only temporarily absorb and delay the peak load for a few minutes while the toilet is being flushed. If the filter absorbs the sulfide load only temporarily and bleeds it off over a period of hours, noticeable odors are eliminated. Continuous flow laboratory testing does not measure this “time-delay” influence on surges. In industrial practice, it is not unusual to see carbon beds that have become saturated on a continuous flow basis within weeks continue to serve very well as peak absorbers for many years.

    There are limits. Eventually the carbon becomes fouled by non-volatile reaction product--as I said, I have seen sulfur deposits in my filter when it was spent--and damaged by acid build up. Additionally, the bed must be large enough for these slower processes to function.

    I hope your headache isn't too bad. But I like to explain why the difference between one person's "theory" and  reality is so difference. Generally, it is not because science is wrong, but rather because their theory was incomplete. 

    (In 35 years as a chemical engineer and wastewater guy, I got to work with carbon a good bit. More than marine holding tank guys, I'm betting. I learned where most of the bodies are buried.)

    (What got me thinking about this? I've got a couple of articles in Good Old Boat this coming month, one of them on holding tanks. Another guy wrote a good article on safety bypasses, but he got the carbon adsorption bit wrong. Not a big deal, it just reminded me of this chemist detail.)

    Friday, June 2, 2017

    Epoxy Clean-Up

    Strong durable stuff. Combined with either reinforcing fibers or thickeners, it is the most versatile material in the boat builder's arsenal. It is also messy to work with and horrendous to clean up when it gets where it should not. Solvents don't touch it even when uncured, and once cured, it is there to stay. However, until cured, it has one kryptonite: vinegar.

    The weak organic acid in vinegar (acetic acid) disrupts the polymerization cycle, stopping the cure. I also breaks the surface bond of uncured epoxy by capping off the reactive ends. It does not dissolve epoxy, but it does take the stickiness out of it, allowing it to be more removed easily with soap and water.

    Epoxy in the eye is the worst case scenario, but it does happen occasionally, often the result of working overhead. Goggles are the correct preventative, but let's assume you either forgot or didn't feel you could see well enough with them on. Perhaps you removed them after they got epoxy smeared on the lens. While I have not may this particular mistake, others have, and the cure involves a combination of modern first aid and old-school home remedy. It turns our that a vinegar-water eye wash was a traditional treatment for conjunctivitis (pink eye), and while I would go to the doctor for that, vinegar can be just the thing for epoxy in the eye. The vinegar will not dissolve or remove the epoxy, but it will stop the reactivity of the hardener, which is the substance that causes chemical burns in the eye, and render the epoxy inert. It will then be more easily removed by the copious freshwater flush that follows.

    Anti-Epoxy Eye Wash
    1. Rinse several times with a weak vinegar solution (one teaspoon per cup of warm water).
    2. Rinse for 15 minutes with clean water.
    3. See a doctor unless it really feels fine after another 10 minutes or so.  

    I keep one of these at home. I wash it and clean it out at least twice a year, and it goes with me to the boat when I have any painting or significant epoxy project. I have used this many times for dirt or a splash of something in the eye, even if i is not bad. I don't hesitate. The few times when it has been a bi worse, having a real eye wash bottle at my side may have saved my sight. I will never know. I don't want to know.

    Get an eye wash bottle, keep it clean, and keep it close. NOTHING is more valuable than you eyesight. Well, family, and perhaps wearing a bike helmet certainly fall in the same catagory as irreplaceable. Protect them all.

    A minor word of warning: vinegar does increase the solubility of the hardener in water and thus increases the transport of the chemical through the skin. If vinegar is used regularly to remove epoxy from the skin, it can increase the risk of allergic sensitization.

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    "Keeping a Cruising Boat for Peanuts" and "Singlehanded Sailing for the Coastal Cruiser" are now available for Kindle through Amazon. I still recommenced the PDF version, since the Kindle conversion process disrupts the page design and because I up-date the PDF version more frequently.