On Board with Mark Corke

Repairs and upgrades - Norcold and Simrad

This picture (above) was taken with taken with my iPhone at close range and as I could not get far enough back so you will have to excuse the parallax error, but it shows the fairly well, I think the progress to date on the new fridge installation. The old fridge was noisy, the seals were worn so it ran all the time, it used a ton of electricity, iced up with gay abandon and the small freezer compartment door did not properly close. With that said I am pretty impressed that it managed to soldier on for 26 years, but it had to go and is being replaced with another, which like the first is from Norcold. The fridge is a dual voltage 12/120 model which looks pretty slick, but installation has required some modifications to the cabinet work around the unit as the overall size is a little smaller. The old fridge had what can best be described as flange around the unit and this screwed into the wooden framework. This had two functions, it sealed the gap between the fridge and the cabinetry preventing dirt and debris from entering and secondly held the fridge in place preventing it from moving when the boat moved about at sea. The new fridge lacks the flange which I miss and I hope that at some time in the future Norcold sees the wisdom in reintroducing this feature to at least some of the models in their range. The 0788 model that I am installing is fixed in position with screws through the feet which are visible when the door is opened. This works well on my boat but I could see may be a problem where the fridge is located higher from the sole where a solid attachment point may not be available. Because the fridge is less tall than the original I also have room for cutlery drawer and you can see the drawer front temporarily taped into position for photography purposes.

After talking with the technical folks at Norcold I found out that I had been operating my fridge incorrectly in the past. I had always assumed that with a dual voltage fridge one had to turn off the DC breaker before turning on the AC breaker to power the fridge but it seems that I should have been keeping both the 12 volt and 120 fridge breakers on when I was aboard. Apparently there is an automatic relay in the back of the fridge which by default runs off AC voltage, if this is interrupted or unavailable then the appliance automatically switches to 12 volts DC until 120 volts AC is restored. They have been wired that way for years, it seems, but I never knew, and now you do too.

I've never liked the way that many radar and chart plotter displays just tend to get bolted down to any free bit of space with the cables sprouting out of the back. I think this messy and I wanted to do something better. Seaglass has surprisingly never had a multi function display installed at either helm and this is something that is being addressed during this winter and spring fit out season. The truth is that I have a bunch of equipment on long-term loan from the good folks at Simrad for a series of features that I have been working on about installing an NMEA 2000 network. At the heart of the system is a beautiful 16 inch NSS evo2 MFD. I've played about for ages trying to work out the best location for this with initial thoughts that it might go above the windscreen. This looked like a good bet and would have worked well with the general refit of the headliner and lighting upgrades but a mock-up showed that it was just too far forward of the helm seat to make controlling it as easy as it could be. So further head scratching and another mock up brought me to the point I am at now with what I can best describe as a teak nacelle which sits on the self and to port of the main  steering compass. The MFD can now be controlled with relative ease from the comfort of the helm seat and the large screen is easy to read from most anywhere in the salon making watching movies when swinging on a hook a distinct possibility. I am going to miss the flat surface on which I placed pilot books and charts when underway and so I have to find alternative placements for these, but I think the trade-off worth it. 

In the picture above the MFD has been temporarily dropped into place just to see how it will look when finished properly; there's to be a matt black surround between the teak 'eyebrow' and edge of the MFD but this will not be installed until after the nacelle has been varnished to match the rest of the boat interior. Also, you will notice that the teak is still somewhat of a rather odd color. The nacelle is made of 9 mm marine ply onto which I have glued teak veneer with the adjoining corners and eyebrow from solid teak. Teak when freshly cut has a definite green tinge but this soon fades and the color reverts to that familiar honey tone within a few days and the nacelle is still in that phase but by the time the varnishing starts the color will be somewhat different to what you see here. I should add that the color continues to mellow even through the varnish and so with time will blend in well with the 25-year-old teak interior.

 

Easy build Dado jig

 

I spend a fair bit of time in the wood shop making projects for the boat and the house. Often times that involves some cabinet work of one sort or another and although it may be acceptable to simply glue and screw cabinets together if they are to be painted it is not the best way if they are to be finished bright or the showing any sort of fixings is unacceptable. One of the best ways is dado or as we say in British English cut some housings. These are simply a groove across one board into which another board slots. Useful for all sorts of things but the trick is making sure that one board fits neatly into the other. Sometimes the component parts will be solid wood but most often they will be some type of panel material; MDF, plywood etc. To a novice one would think that if you bought three quarter inch plywood you would only have to cut a three quarter inch dado and all would be well but plywood can often be slightly thinner or even slightly thicker than it's stated width so a more accurate method needs to be found to ensure that no matter the thickness of the material the fit will be snug and attractive.

 Whilst it is true that you could simply measure the thickness of the boards and cut to that you are still faced with the problem of accurately machining the dado. This simple jig which is shown below is but one way of overcoming these problems. Simple to make it will work with almost any router and can be knocked up from offcuts in about 30 to 45 minutes.

 The actual length of the jig is dependent upon the actual width of the material that you wish to dado but for most purposes I have found that 24 inches will suffice for all but the largest cabinet jobs.

 

First up is to prepare two lengths of 2 by 1 inch material. These have to be dead straight and true, any inaccuracy here will be transferred to any dadoes that you cut. I used poplar which is a stable timber and trued them up on the jointer but planing them by hand works equally well but carefully check them with a T square for true.

 

These are then screwed to a couple of pieces of plywood the same length as the timber that you just cut. I found that prefinished birch is ideal but use what you have. Make sure that the plywood is at least half the width of your router's base plate.

 

When the wood has been screwed to the plywood it should look like this.

 

The next stage is to chuck a router cutter into your router which can thinner than the width of the dado you wish to cut but not wider. I have found that a half inch cutter is ideal as I mostly work on three quarter thick boards, just remember that the cutter that you choose can be smaller than the material than that you will be cutting but not larger. This will become apparent as you become familiar with the process. With the jig clamped firmly down to some scrap make several passes and cut through the jig. Do not try to cut through the thickness of the ply in one go, you will have a cleaner cut with less tear out if you take it steady. Also make sure that the base of the router is held firmly against the timber screwed on fence. The width of the jig is now very accurately machined from the fence to the edge of the plywood. Do this by cutting through the plywood along both fences so you end up with two identical but separate pieces.

 

To cut a dado line up the edge of the ply with the marks on the board where you want your shelf or whatever to go and clamp the jig in place. Set the cutting depth of the router so that it removes between a quarter and three eighths of an inch for three quarter thick material (LESS if the material you are cutting into is thinner) Then keeping the base plate of the router hard against the jig cut the dado.

 

Without moving the first part of the jig squeeze a sample section of the material that is to fit into the dado between the section of the jig that you just used and the new section and clamp the second section in place. Remove the sample material and the first half of the jig and without altering the depth of cut on the router make a second pass.

 

TA DA. A perfect dado every time all ready for glue up.

 

TIPS

 

When routing against a jig always move the router from right to left to avoid it snatching and running away from you.

 

Mark the jig with a sharpie to show which cutter you used as the jig will only work with that particular cutter and router combination. Using a different cutter will lead to inaccurate dadoes.

 

 

Tree Frog pad

No matter how well you may be organized aboard there is always some small bits and pieces that you need to find a home for. At the helm I like to have my cell phone, a couple of pens and other such detritus close at hand. The trouble is that you often put them in what you think is a pretty secure place only to have them vibrate across the console and crash to the floor. Placing them a cup holder works of sorts but you can't see the screen on the phone and with everything jumbled up together damge is possible. The Tree Frog Pad really seems to be the answer to my prayers. Resembling what I can best describe as a small cutting mat the pad is super sticky and clings to almost any surface. No more than an eighth of an inch in thickness the pad stays in place even on vertical surfaces if you wish although don't expect it to hold a cell phone in place at this angle. But at a 45 degree angle it works perfectly for holding whatever I place on it in. 

The pad has a rather unusual feel and does feel sticky to the touch although this is the nature of the material which does not in fact have any adhesive attached to it. The pad does pick up bits of dirt, and what my wife refers to as belly button fluff but this is easily washed off under a warm faucet without effecting the stickiness of the pad whatsoever.

The best part about the pad is that you can use it any where and you do not have to screw into the boat. Not as robust as perhaps the SeaSucker mount that I blogged about here and here but then again it is meant for a different purpose. A 7 by 9 inch pad costs $12 which is worth the price if only for all those times that I do not have to bend and pick my phone off the cabin sole.

Setting up a rig with Spartite

 

Q.

I am having problems with my mast wedges every season. They are splitting and are confusing as to which ones go where. Is there a better alternative to wooden wedges?

 

A.

I have seen wooden wedges on many boats that look like they should have been used for kindling. One way to rid yourself of the wooden wedges would be to use thick rubber sheets that are cut into rectangles – one to go in front of the mast and one behind the mast. They should be long enough to reach around to the sides slightly and cut to fill the depth of the partner. The trouble with this system is that you will need to select rubber that is thick enough when compressed that it will support the mast tightly, but not so thick that you can’t get it in. It should be just oversized slightly, maybe an eighth of an inch. Position the aft one and tape it temporarily. Rig a line around the front of the mast and back to the cockpit through a block to get a fair lead to a winch. Tension the line until you can slip the forward one in place (sometimes it helps if you lube it with spray silicone or soap). Once you have them set, release the line and add a long hose clamp around both pieces of rubber to hold them from slipping down on the mast when sailing. The trouble with this method is that you or your yard will have to reinstall them every year.

 

Spartite is the other method which once installed is simpler to step and unstep. It is a liquid chock that forms a neat, tight fitting collar around the mast. To use the Spartite you will need to center your mast in the partner, deciding where the best position fore and aft would be. Use lines to hold the mast in position. Wax the inside of the partner to prevent the Spartite from sticking so that the mast can be easily removed in the fall. Dam off the underside of the partner and use modeling clay to fill any gaps. Make sure to remove cushions or anything below that would be damaged if it would run down below. Use plastic or paper to catch any drips. Make a funnel of thin cardboard if it will make pouring easier. Once everything is ready, mix up the material per the manufacturer’s instructions and pour it into the joint. Bring the level up to the top of the partner and allow it to cure. Once cured, you can seal the top joint between the chock and the partner with some marine caulking to make it watertight.

 When it is time to unstep the mast, the chock will stay with the mast and be ready to be dropped back into place in the spring. The Spartite chock is an easy way to end having to use splintered and confusing wooden wedges.         

Fold up sink number 3

I was out on a boat the other day and was very pleased to see this nifty fold up basin in the crew compartment. I have touched on fold up basins and sinks here and here before but can't for the life of me see why they are not more prevalent aboard many more boats. The fact is that they make a lot of sense especially in heads compartments that are often crowded at best. Many boats use the heads compartment as a shower and it seems that you may spend five minutes taking the shower after which you need to spend half and hour cleaning up and drying the compartment. A fold up basin such as this model which is marked SCM, Bremerhaven would allow more room when using the compartment for showering and make cleaning up far simpler affair. A quick trawl of the internet showed no extra information on these particular basins which I suspect are no longer made. More's the pity.

 

Toilets on boats - Keeping a clear head

Probably the simplest arrangement that is possible to have aboard a boat is the ‘bucket and chuck it’ method, a cedar bucket that is simply tipped over the side once you have seen to business. Whilst this still works well offshore it is no longer acceptable in no discharge zones and so something a little more sophisticated is required. In some parts of the world it is still perfectly acceptable to have a marine toilet that takes it’s water in flushes through the bowel and then discharges this complete with contents back from whence it came. It will be seen that this is only a slightly more sophisticated take on the bucket the only difference being that one does not have to hang over the side to empty the contents but for all intents and purposes it is the same.  Indeed it was this arrangement that I had on my own boats for some time; coupled to a Lavac marine toilet which has no moving parts it worked perfectly. pipe runs were short and blockages non existent and the image below is copied from the Lavac site to show how it is arranged.

In recent time things  have started to get a little more complicated and with the advent of no discharge zones it is almost essential to have a holding tank aboard to comply with USCG and EPA regulations. If the boat were to only be used outside no discharge zones then we could just have the no holding tank arrangement but because we have to travel through no discharge zones to get offshore then a holding tank is required. Also given that most recreational boats are operated in inshore zones and may may never operate or venture into open ocean a holding tank is a must.

I guess the simplest for of holding tank is a Porta Potti style chemical toilet where the tank is directly below the bowl; there are no pipes and waste basically travels by gravity to the tank where it can be emptied out ashore later. Porta Potti have got a bad rap over the years and summon up images of a smelly outdoor toilet at some remote camp site. In fact providing that a Porta potti is maintained well, the proper chemicals are used and it is regularly emptied they do not smell at all. They also make sense on small boat such as weekender where there is little room for anything else or on board a boat where the heads will only be used only very occasionally. 

The next step up from this is some form of proper marine toilet and this is where things can get complicated and in fact are often made much more complicated that they need to be. I have seen all sorts of contorted pipe work for toilets, with discharge pumps, macerators, twin holding tanks, sharp right angle bends, pump outs and all other manner of arrangements. The fact is that the more pumps, pipe work and other parts that you have the system the more chance there is of it either (a) blocking up or (b) malfunctioning in some other way. But having said that many of the problems that can be encountered with the head are down to operator error. When guests come aboard especially those that are not familiar with marine toilets I make sure to show them how to work the toilet. Even then often because they do not want to wake other crew members at night they will not give the head the required number of complete pumps. What you have to be aware of is that the waste once it disappears from the bowl has to travel down a pipe to the holding tank. if the head is not pumped enough, the waste, instead of residing in the holding tank sits in the hose somewhere where it can either cause a blockage or start to smell. In most cases on boats that have manually operated heads you need 10 to 15 good pumps to dispatch the little (or big) blighters to the holding tank and thus flush the hose clean. 

On the vast majority of smaller boats, those up to 50 foot say, sea water is the normal water used for toilet flushing. Used for good reason sea water is both plentiful and free but it is not ideal. Firstly sea water contains millions of tiny organisms that you can only see under a powerful microscope when these are flushed though a toilet aboard they enter an alien environment where they die. As they die they decompose and produce a sulfurous smell and it is this that you can often smell aboard especially if the head has not be flushed for sometime. Secondly sea water can cause severe calcification on the inside of waste hoses reducing the diameter and preventing waste from passing through. Also using sea water also means that you have to have a skin fitting and sea cock and as such this is another hole in the boat that has the potential for leakage and in extreme cases sinking of the boat if the hose fails. Far better in my book is to use a fresh water flush where water is drawn from the tanks aboard. Incidentally if you are worried about contamination you can use a check valve to prevent anything backing up but in practice this is unlikely to happen especially if you have a vented loop in the intake hose. Fresh water smells sweeter and without the little critters the sulfurous smell will not be present. Calcification is likely to be much less also although the waste itself can cause problems.

 

Going back to my earlier point about most recreational boats being used in inshore waters and no discharge zones that means that waste should go directly into a holding tank. Most boats are fitted with a Y valve which enables waste to either be pumped to sea, when outside the no discharge zones or with it moved the other way into the holding tank. If the boat is used on inshore waters then the Y valve will be always diverting waste to the tank and given that any valve is an obstruction to the flow of waste why no do way with the Y valve altogether and send the waste directly into the holding tank which has the added benefit of doing away with another hole in the bottom of the boat, the waste outflow which is normally inch and half in diameter. It will be seen as shown in the diagram that the system is very uncomplicated, pipe runs are unambiguous and there is far less to go wrong and get clogged up. Providing that the holding tank is emptied on a regular basis there should be no problem and in fact a 15 to 20 gallon holding tank holds a lot of poop, the average flush only uses 3 to 4 pints of water, and even on a weeks cruise a couple would be very hard pressed to fill that up. 

Another point about the installation of toilets and that is that hoses should avoid having any droops in them where waste and water can collect, a steady downward slope to the holding tank is ideal and will ensure that blockages are almost impossible. On smaller boats toilets tend to be manually operated but I am a big fan of electric toilets as pressing a button makes sure that the toilet will be flushed properly with the correct amount of water and they are more akin to the toilets that guests find at home so they do not feel intimidated by them. Holding tanks must be vented to the outside of the vessel and this is normally achieved by having a small vent fitting on the topsides well above the waterline, this vent may or may not have a charcoal filter installed. On a closed system such as this the only other connection to the holding tank would be the deck pump out. 

Installing a system such as this eliminates two holes in the bottom of the boat, does away with lots of pipe work and associated fittings, saves money and ensures that you will comply with USCG regulations. Should you ever decide to go offshore on an ocean passage then you can either supplement your heads with the cedar bucket or install a Y valve and waste sea cock.

Teak folding table

Walk around any boat show and it seemsthat almost every other booth has a new take on a drinks holder. I like a cold one as much as the next man but some of the these drinks holders are very expensive and pretty recherche in the extreme. While it is true that you may want some place to hold your drink whilst out boating ideally everything aboard should have more than one configuration and be capable of more than one function so it was with great joy that I saw this table arrangement on a Freedom 36 the other week. I think that the pictures are fairly self explanatory but what I like about this table / cup holder is it's simplicity; no fancy hardware and nothing to break. As you will see it is all made from teak and teak plywood and consists of a drinks holder securely clamped to the crash bar ahead of the compass binnacle. When out cruising this offers a great place to hold mugs and cans without fear of spillage and yet within easy reach of the helmsman and crew in the cockpit. But what really sets it apart is when you get into port and you need to set up the table for alfresco dining. The table is simply lifted off it's stainless hooks and pulled away from it's clips keeping it neatly in position and slid into the horizontal, no metalwork, flaps, hinges or other impediments to adjust or break off for that matter. I could also see a use for this table arrangement down below, on a powerboat for instance where the cup holder section of the table could be attached to a bulkhead or other surface. Obviously not as solid and secure as a pedestal mounted table perhaps but more than adequate for use when in port or clement weather and unlike a demountable pedestal table no pole to store and get lost.

 Just in case the photographs do not make it perfectly clear I enclose a cross sectional sketch so that you can see the relationship of all the parts and as ever you can click on any of the photos to make them bigger.

 

Cruzpro transducer

 

One of the perennial problems with through hull speed transducers is that the little paddle wheel seems to work well for a day or two after launch at the beginning of the season when it is all fresh and clean and then it stops. The problem is that those little paddle wheels are very susceptible to clogging up with any small bit of weed or other floating debris. Most of the transducers made for the likes of Garmin, Raymarine and so forth are actually produced by Airmar who produce good products and I was very pleased to see that they came out with a new speed transducer a couple of years ago called the CS4500 which has no moving parts and measures the molecules of water moving across the face of the transducer, all clever stuff and of course the best part is that as the transducer looks similar from the outside to the well known depth transducer there is nothing to catch weed or critters. The only problem with this transducer is the cost which runs to about $650 which puts it outside the pocket of many boaters. The only answer is either to get stuck into the cycle of removing and cleaning the paddle wheel every few days and all the problems that that entails or coughing up the lolly for one of the CS4500 transducers.

One of the other possibilities is to install The CruzPro SOG1 which converts a GPS signal into an
electronic impulse that can be read by a log speed display which in my case is the Raymarine ST40 unit. The CruzPro works on the NMEA 0183 protocol so it should work with most any display unit but may wish to check with the manufacturers before going ahead. As you probably know every GPS set calculates speed over the ground (SOG) and there is usually a page on the plotter or at least a small box that can be bought up to display this information. Basically the Cuzpro unit takes this information and feeds it to the speed or log display which is great. The good news of course is that the small CruzPro black box can be installed almost anywhere aboard and being a solid state unit with no moving parts should perform with no attention unlike the paddle wheel that gets clogged at a moments provocation and as we know needs cleaning almost every time we go out boating. The down side is that the speed is SOG not through the water. You could argue that speed over the ground is more helpful and it is in most cases because we want to know how long it will be before we get somewhere but there are times when is most helpful to know how strong the tidal stream is; calculating the best course to steer, how much tide we have moving under us when we are anchored and such like all things that the CruzPro will not give us. We can of course often calculate the tidal stream from the tidal atlas or chart but that is not as convenient as simply reading it off a display.
Think of it this way, if the boat is in the slip at the marina and is therefor not moving we can often turn on the speed display and assuming that the paddle wheel is not contaminated and is functioning properly we can read off the speed of the current which could be an important consideration to take into effect if we are just about to leave the dock and want to know how the current might affect the boat. Assuming that the paddle wheel is operational we only have to
turn it on and with the boat stationary and facing into the current we can read off how fast the current is running.

For all that I still think that the CruzPro unit is a good one and I have one on order, it costs just $100 and will let you know how the installation and sea trials go.

Keeping the beer cool

Just recently the weather up here in New England has been very hot and humid making the need for some form of refrigeration on the boat almost essential if one wants to keep the milk cold, or have a cold beer at the end of the day. Assuming that you have room  for a fridge on your boat powering it up is always a headache. If you have a shore power connection then the energy usage is not a worry but when away from the dock on a cruise or if the boat is kept on a mooring then things start to get a little more complicated. Sure a small modern marine fridge does not consume as much as some of the electrics on board but on boats that do have fridges they tend to be run 24 hours per day and that does add up, 50 or 60 amps in a 24 hour period.

 

Dometic are probably the biggest supplier of duel voltage fridges and freezers to boats but what is not often realized is that they also make fridges that run on either 12 or 120 volts or propane. Intended for the RV market there are certain considerations with these not least the explosion hazards, but we have that with stoves anyway and any such risks can be lessened with safe and approved installation practices and monitoring devices. The other thing about propane fridges is that they do no like to be operated at an angle or generally shaken about and for this reason on an RV the stove would typically be operated on 12 volts when under tow as electricity can be supplied from the towing vehicle then switched over to propane after arriving at the campsite and the unit is stationary.  This same approach might also be good for smaller boats too which could often have amps top spare when underway but need to conserve battery power when moored or anchored.  I have not spoken to Dometic about this idea and I am sure it would not work for all boats but I am sure it would work for something slow and steady like a trawler.

Silencing halyards

Checking back through my blog postings it I am amazed to see that it was a couple of years ago or more that I issued a plea to fellow sail boaters here  to stop their halyards from banging on the mast and keeping me a wake at night in some bucolic anchorage or marina berth. What I said then still holds true, not only does the noise drive me insane until I have to get up and wander over to some other persons boat and stop the constant 'ting ting' of rope against mast but I also hate to think of the unnecessary wear that is being placed on rig and rigging. I tend to use a bungee to hold my ropes away from the mast which does the job but I was out on a boat yesterday and whilst inspecting the rig I looked aloft and saw some small subtle open ended u shaped hooks attached to the front of the spreaders. When the boat is being put to bed overnight or the sailing is otherwise finished for the day the halyard is simply snagged into the fitting and tightened with the winch. Perfect and no bungee cords to look untidy or get lost.

 

 

The cost is so minuscule I can't for the life of me understand why these are not all standard equipment on every sail boat. I am sure that these are not new but have only just become aware of them.