On Board with Mark Corke

Hybrid power

 

There has been lot of discussion lately about alternative power for both sail and power boats. One of the options that has been getting a lot of press is the hybrid power system. Essentially it consists of a diesel engine connected to an electric motor. This gives the boat operator the option of running the boat via the diesel directly, the electric motor directly or a combination of the two. There is a lot more to it than that but in a nut shell that's it.

Hybrids have been held up as the boaters answer to saving the planet, I'm all for ecology and taking care of our surroundings but in my view the use of a hybrid power plant in a recreational boat is white elephant. Of all the boats that I survey many of them have well below 1000 hours on the engine and often much less. In the grand scheme of things 1000 hours equates to about you driving 4000 miles in your car which is hardly anything. When you factor in the additional cost of the hybrid, the additional wiring etc etc it makes no sense at all.  Plus it is a sad fact of life that most boat engines wear out not through use but from under use as they rarely reach optimum temperature. Also most boats are over powered. M advice is to buy a smaller motor use it wisely and often and it will repay in lasting longer and still use less diesel than even a modest hybrid unit.

Unscheduled stop

I am writing this from my hospital bed. After delivering a boat to the Newport Boat show I became ill which necessitated a trip in an ambulance to the local hospital. It is very frustrating as I can see the harbor and all the boats from my bed.

 

More to follow and hopefully back on a happier boatng topic very soon. But very tired now.

 

All the best

 

Mark

Home made saw guide rail

Often time you may have to cut plywood sheets into small sections. It could be when making cabinets for a boat interior or any one of a hundred other purposes. Getting a straight cut is essential if everything is going to fit together properly. I used to mark a line and cut it free hand, either that or clamp a piece of straight wood and runs a saw along that. That works of course but it has two drawbacks; it take time to set up and you have to measure the off set of the saw away from the guide strip that you have just clamped on. This quick and easy tool makes cutting sheets with a circular saw a snap and gives precise, consistent results. You will have to work out the details to suit your own make of saw but as you can see from the pictures it is made from two pieces, the bottom piece is quarter play wood and the heavier top section that the saw runs against is half inch thick.

To build

Cut a section about six or seven inches wide from the edge of a sheet of ply then glue and screw this to a wider piece of quarter ply. The manufacturers edge on the half inch ply will be straight so make sure that it is this edge that the saw will be running against. Make the quarter ply wider than you need then make a cut with the saw cutting through the thin plywood, this gives you a nice straight edge which from now one you simply have to align with your marks on whatever you are cutting, clamp in position and voila! a perfectly straight cut.

Two points to remember however. Use a fine tooth blade in the saw for the best  finish and secondly clamp the guide onto the section of ply wood that you want to keep. If you clamp the guide onto what will become the unused or unwanted piece the bit you do want will be undersized because of the width of the saw blade. I hope that pictures make it all clear which as ever you can click on to make larger. If you have any questions or comments please drop me an e mail.

This gives an overall impression of how the saw guide works. It is 8 feet long so the same length as a regular sheet of ply wood. In this picture I am placing it into position prior to making a cut.

The edge of the quarter inch ply wood is exactly aligned with the marks that you wish to cut to.

The guide is then clamped into position with a couple of strong spring clamps. Make sure that the grip is good however some of the cheaper clamps are not up to the job and you may be better off with a G clamp if there is any chance of the guide moving.

Make the cut. A little candle wax on the guide will make the saw slide smoothly. Make sure also that you hold the edge of the saw plate to the guide and you will be rewarded with a perfect straight cut every time.
   

Edey and Duff close

It came as a bit of shock to me when I found out that Edey and Duff, the Matapoisett, Massachusetts boat builders were to cease business.

According to a press report that you can read here there have been several reasons given for the firm closing it's doors for the final time last Tuesday but what ever the reason it is very sad nonetheless. One of the most successful designs that the yard produced was the Croker designed Stone Horse which is shown in the photo above.

At the time the yard closed they had ceased production of the 23 foot cutter and were instead concentrating on their other designs, the Fatty Knees dinghy, the Stuart knockabout and the Doughdish. One of the reasons given for the closure of the yard was the death of David Davignon general manager of the yard and although this had serious implications for the small firm I think that it was this associated with the expiration of the boat yard lease and the general down turn in the boat building economy that all had an effect on the ultimate outcome. Interestingly I spoke to Davgnon a couple of years ago and at that time reintroducing the Stone Horse looked like a distinct possibility. I hope that not only this design but also the other Edey and Duff boats will rise again in the very near future. My heart goes out to those that lost their jobs and I hope that they find alternative work in the boat building industry.

Foul Play

Every year I very carefully clean and anti foul the bottom of the boat ready for the coming season. Part of that ritual includes cleaning the transducers for the depth instrument and log. The depth works without a hitch but I am lucky if I get more than a week out of the log before it packs up. There is nothing intrinsically wrong with any of the instruments on the boat the problem is with the paddle wheel transducer. These paddle wheel transducers have been around for quite some time now and work by measuring the speed that the little paddle wheel revolves at and thus giving a corrected read out on the display in the cockpit or helm station. The problem is that for the wheels to work properly they have to be free to spin as the boat moves through the water any slight impediment to their free wheeling means that they either don't read properly or not at all and so it is in my case. There is always a lot of weed in Maine and this year has been especially bad for eel grass, which wraps around propellers and anything else that happens to be in the water as it passes, including paddle wheel logs. So for this reason I am transitioning to an ultra sonic transducer of the type shown above. With no moving parts, they measure speed by reading particles as they pass by, and nothing for the weed to grab hold of I am looking forward to the log working all year with no problems.

Made by Airmar who make just about all the the transducers out there  it is simple straight swap and because the internal dimensions of the through hull sleeve are identical I can slide out the old transducer and slot in the new one. Well that's the theory at least, I'll let you know how it works out.