On Board with Mark Corke

Electric outboards

I've long had a fascination with electric power for boats. I can see that for many day sailors and those that do not venture far from the dock and a ready supply of shore power electric power is the way to go. 

I have actually been using an Minn Kota electric outboard on the dinghy for the past few years and have been very impressed. Light to store on the mother ship I don't have to mess with gas and the quiet is a blessing. To supply the power to the motor I use a portable battery meant for jump starting cars. I can plug in into the main ships charging battery when back on board and it charges up from flat in a couple of hours ready for next use. The whole outfit, engine and battery weigh less than the 2 hp Yamaha that I used to use. In fact I use the electric outboard so much now that I gave up with the gas engine and recently sold it. I do love the quiet and so do the neighbors on adjacent boats when I have to run the dogs ashore early in the morning.

Although I have yet to try one out the Torqeedo motors look good at first glance. They have been out for  while now and what sets them apart from the Minn Kota and others is that a detachable Lithium Ion battery is incorporated into the top of the motor itself. This means no cables in the boat with the engine as compact as a small gas outboard.

The 1003 model shown above has the equivalent thrust of a 3 hp gas engine the makers claim thus making it a realistic replacement for auxillary power on the back of a small day sailer, larger dinghy or RIB. Priced at $1900 it is not cheap but it does have some neat features such as a display built into the tiller handle showing the rate of discharge and remaining range based on the  amount of battery juice left.

If they can get the price down a bit making the engine more attractive to buyers then I can see that I will not be the only person in the harbor zipping around in near silent motion.

Miami Boat show

Next week I am off to the Miami boat show where I am acting as one of the judges for the NMMA innovation awards.In addition to judging the awards I shall also be trying out and inspecting some new products that will be debuting at the show. I'll take my camera with me and try to get them posted up on the blog as soon as I can. Some of the products are so new that they have been embargoed until next week so you will have to wait till then uintil I can tell you all about them. What I can tell you is that there is going to be some interesting developments in LED lighting. Several companies will be showing new underwater lights in addition to some new interior and navigation lights.

Mallard - Golant Gaffer

I have had a fair few enquiries about Mallard my Golant Gaffer that is currently up for sale. Specifically I have been asked for extra details and pictures. If you are interested you can find them by clicking here which will take you to the listing page of Gray and Gray yachts who are acting as brokers.

Canoe builder - Walter Walker

Walter Walker is not a name that springs to mind for many readers of On Board but if you have an interest in canoes as I have then you will know that Walker was the last of the old time builders of wood and canvas canoes.

Born in 1907 Walker died just two weeks before reaching his 102nd birthday. Initially trained as furniture maker Walker soon moved the the Lakefield Canoe Company in Ontario where he worked for many years, but he is perhaps best known for his work at the Peterborough Canoe works where at one time there was in excess of 100 workers turning out the beautiful canoes.

Walker did not ever seem to really retire and although he stopped making canoes for large firms he continued into old age in his own shop making canoes and paddles until only a few years before his death. 

Although Walker actually died at the end of last year it is only now that I have got around to mention his passing but it is heartfelt nonetheless.

Incidentally if you want to find out a little more about this method of canoe building or are perhaps interested in building your own wood and canvass canoe you might like to check out my friend Jerry Stelmok's website by clicking here.

Cheap boating

How about this then? Not the most elegant of craft I'll warrant but how fun. I spotted this boat while searching for something on the internet. Apparently it is made from three sheets of three eights ply wood from Home Depot or some such other emporium. Although yet unpainted it will according to the builder have a total cost of less than $100 which presumably will be excluding the motors which appear to be a 3.5 hp Johnson and an electric minn kota trolling motor.

If you look closely you can see just to the left of the main engine a cool bag which presumably is for keeping the beer cold. I am not sure what sort of keel the boat has but in anything above a whisper of wind it must blow around all over the place. I don't think that the builder intended it to be any other than a bit of fun, but which ever way you look at it you can't get on the water any cheaper.

Air hoses

I use air in the workshop and on the boat a lot. Air powered tools are generally lighter and more efficient than their electric counterparts. There are less moving parts and they tend to be tougher I have found. Even one of the small compressors is a useful addition to the boat builders workshop and the ability to shoot staples when building something like a strip planked boat or canoe is great the only downside is often the air hose itself. Most often seen are the coil type air hoses that seem to kink and snag on every little thing, they knock over paint and epoxy cans and generally are big nuisance. Their one and only one benefit is as far as I can see is that they are cheap. Far better I have found to spend a little extra and get something far better. The picture above shows the hose that I have recently started using. About three times the cost of the coil types but made from soft material it won't kink, or knock opened cans across the boat or from a bench top. I got mine from Home Depot and I have to say that I have fallen in love with my air tools all over again.

The hose has a working pressure of up to 300 psi which is far more than you or I are ever going to need and for the lack of aggravation alone has to be worth the money. It comes in a 50 foot length so one should be fine for almost all of us but if you have a very large workshop or are building a mega yacht then you could obviously join a couple end to end.

Moving day

I am aware that i have not written much of the hands on and how to content that I like to share of late. The reason being is that I am in the middle of a house move that happens to coincide with the Christmas holidays. I have several boats and a workshop to move from one place to another and when I get to the new house have to set up studio and workshop. This is all going to take a couple of weeks but bear with me, after the move the workshop promises to be bigger and better than that which I have now so all being well I should be better placed to bring you plenty of new and exciting projects.

Happy Thanksgiving

A happy Thanksgiving to all On Board readers.

Stitch and tape construction

So called stitch and tape construction is now widely used in all sorts of boats from those that are built from plywood as I have shown here to those that may be built of more exotic materials. As it's name implies the ply panels are at first joined together with temporary wire stitches the inside, joints are then made with epoxy then after the epoxy has set the stitches are removed before the exterior joints are made with epoxy and glass cloth.

Below is the sequence of events for those that are interested in constructing a boat using the stitch and tape method. The picture show a small boat that I was building for my son but the technique will be similar in all cases except that the plywood may be thicker and the epoxy joint will be larger to thus spread the load across a larger area more effectively. I have personally built a number of boats using the stitch and tape method which produces a boat which is both very stiff and strong. One word of caution would not go amiss here and that is to check the boat dimensions carefully before applying epoxy to any joint. If a boat is wired up out of square or in other words with a twist in it once the epoxy sets up the twist will be there for evermore and the boat could be useless.

1 Mark up the planks to be joined. Clamp them both back to back so that you can drill through both of them at the same time. I was using 6mm ply so I measured in about half an inch from the edge to prevent the stitches from tearing out.

 

2. Spacings will depend on the amount of bend and tension that the plank will be subjected to. I set mine at 6 inch centers and this will be good for most applications, you can always add more if you find that you need them once you start the actual wiring together of the panels.

3. Drill for the wire stitches. The drill diameter should be just slightly larger than the wire gauge that you are using which in my case was a sixteenth.

 

4. With all the holes drilled open out the panels. Precut some lengths of copper wire and prebend them into a large u shape,  then feed them through from what will be the inside surface of the boat.

 

5. Twist them loosely together on the outside with the pliers. Leave them fairly loose, you can always snug them up a little later. Drill a few more holes and add extra wires if you feel that what you have is insufficient to hold the panels to the correct shape.

 

6. Continue wiring all the panels together. This was small dinghy so I was able to wire the entire boat together before I even thought about breaking out the epoxy. This is a fun part too as the boat starts to take shape very swiftly. As the boat was small I was able to hold each panel myself as I wired the boat together. Had the boat been any larger then a helper would have been useful; one to hold and adjust the panel up or down as required and another person to do the actual wiring up.

 

7. The wiring up almost complete. Note the temporary spacer to hold the beam of the boat to the correct dimension.

 

8 With the wiring complete it is time to mix up some thickened epoxy, I used wood flour, and spread it into the inside joints. Neatness pays here and will save hours of final sanding if you are careful. After spreading on the thickened epoxy smooth it out with a shaped stick like a tongue depressor or the back of a plastic spoon. Larger craft will have fillets that are much larger than these shown here and for that you will need to make a consequently larger spreader and smoothing tool.

 

9 This is how the finished joint should look, neat and well executed.

 

10 After leaving the epoxy to set up overnight you can remove all the staples. Most if not all should pull out with a set of pliers but if they are at all reluctant to come out then heat them with a soldering iron. This has the effect of softening the epoxy a tiny bit and allows the wire to be withdrawn.

The boat is now essentially a one piece monocoque structure but there is still a lot of work to do, the outside joints have to be made and the fiberglass reinforcement added. I'll be covering these steps in part two.

Multi panel test

I've finally got around to testing the MultiPanel sample that I have had sitting in my shop for the past few months. A very light weight foam building material it is fully compatible with epoxies and other commonly found products used in boat building and repair. MultiPanel is a closed cell foam and is completely non hydroscopic, in fact if you pour water on it it just runs right off. Although the information on the website says that you can paint right over the top of the panel I suspect that most users will find the panels most useful as a core material with epoxy and glass or at least with some other surface material attached.

My first surprise was how easy it is to machine and work. It can be cut with standard woodworking tools and with a fine tungsten blade the machined edge is near perfect. I was also expecting there to be clouds of dust but this was not the case at all. Many foam materials produce a lot of static when machined and cut which soon covers everything but this did not happen with the Multipanel.

As an initial experiment I glued some oak veneer to a sample. The veneer I was using was of the pre glued iron on type so I warmed the panel with a hot air gun and pressed the veneer into place.

While the glue was still warm I placed it into vacuum bag using my handy vacuum food sealer and allowed it to set up for about 15 minutes.

After removing from the bag I trimmed the edges one the table saw and as you can see the cut was perfect with no splintering of either the oak or the panel. The oak could now be finished with varnish or other coating as desired. ( Click on the images to make them larger)

Of course this is just a preliminary test and I have other techniques that I am trying out. It is possible to thermoform the Multi Panel. Basically after heating in an oven the panel becomes very pliable allowing it to be either free formed or set over a former and allowed to cure. I could see that this would be a great way of forming such items as curved bunk fronts and other items aboard. I must confess that I did try to use the heat gun to soften a small panel and although I did get it to bend a little I was unable to generate enough heat in the whole panel to get it to bend easily. But far from being a disappointment I was actually quite excited, the panel did not catch fire even when exposed to the extreme heat of the hot air gun and heat transfer to the other side of the half inch panel was minimal indicating to me that the Multi Panel would be a very good insulator when used us a core for bulkheads and such like.

I'll bring you an update and some pictures after I have successfully bent a panel or two but I feel very encouraged with the progress of my initial investigations. I could see that the Multi Panel may make an excellent material for many structural components, very light and at the same time very stiff. I am seriously considering using it for the bulkheads in the the new boat I am working on. The more weight I can cut out of the boat the better as this will enable me to use a smaller motor which in turn equals less fuel.