On Board with Mark Corke

Shrink wrap ventilaton

In my last post I mentioned the need for ventilation for shrink wrapped boats. Without it mold will develop and it will not do the boat any good whatsoever. Think of a shrink wrapped boat as a big sealed in green house. As the sun warms the cover it causes any moisture under the cover to be absorbed into the atmosphere then as the sun goes down and the cover cools the still warm air condenses on the inside of the shrink wrap and drips back onto the boat. As it is impossible to shrink wrap a boat without trapping some moisture inside a good amount of ventilation will defeat this condense/drip cycle and allow the air to reach equilibrium thus mitigating problems to a large extent.

At the time that the boat is shrink wrapped it makes a lot of sense therefore to incorporate some sort of ventilation. Costing just $6  a piece these wind cup forced ventilation systems from Dr Shrink could solve many problems. Attached to the outside of the cover these cups which drive a small fan on the inside and duct air through the cover should go a long way to preventing moisture problems. For areas where there is a lot of sun but little to no wind solar powered versions are available.

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.

Oceanair screens

If you are anything like me then you have a list of jobs and projects on the boat that you promise to get around to one day but never seem to. Well one of those on Mallard has been the installation of an Oceanair screen which I have just got around to after what must be 3 years. These really are a beautifully made piece of kit and to my mind at least look fantastic. Available in a variety or standard and custom sizes they blend seamlessly with deck hatches from Man ship, Lewmar and the like. The model that I have installed is the surface model as shown above but you can get recessed models which can be incorporated into the overhead providing you have room, I don't. Even so the surface models are very smooth and stylish and hardly project down from the overhead at all.

The screens come with easy to follow installation instructions but I have found that it pays to take time to ensure that the mounting surface is square and true. Any distortion or twist in the substrate will similarly impart twist into the screen which will then not operate correctly.

 

It really is two in one product as a mesh bug screen pulls from one side and a blackout blind pulls from the other. The former keeps even the Maine black fly at bay and the latter turns day into night which as I like to sleep in total darkness suits me just fine. A strip magnet runs along the front edge of the bit you pull over and keeps the blind securely closed and also as you can see from the top photo both the screen and shade can be pulled to meet in the middle thus varying the amount of light getting through into the cabin.  Easy to install, they look good and work perfectly, all in all a great product and a nice upgrade to the boat.

Webasto air conditioner

Talking to many of the boat manufacturers at the Miami show it would appear that unsurprisingly new boat sales are down. On the flip side many accessory and after market vendors appear to be having a good show.

Interest has been brisk at the Webasto booth where they are showing the FCF-DV which stands for Feel Cool Fast dual voltage. The 5000 BTU air conditioner has been around for a few years now and I can say from experience having installed a few of these in the past that it is a compact, quiet and robust unit. So although the AC unit is three years old or so what makes it appealing to show visitors is that Webasto have done a deal with Xantrex and are now offering the unit complete with an inverter. Of course although you could buy both the AC and inverter as separate units Webasto are offering the two together as package for just under $3000. Webasto are offering a 2 year warranty and technical support on both components and additionally the unit also comes with a purpose built wiring loom and control panel making it a plug and play exercise and therefore for a competent DIYer.

The inverter senses when the mains power is connected and automatically switches off the battery connection so there is one less thing to worry about. My only concern with this whole package is that the battery drain will not be insignificant especially if the unit is working hard. I have asked Webasto for some figures on the battery current drain and will bring you those as soon as they become available to me.

All in all this seems like a good deal to me and perfect for boats in the 26 to 40 foot range. A larger 9500 BTU unit is available for larger craft which as you would expect has a larger inverter to cope with the heavier start up current.

Heaters

   We are still without power at home which by osmosis also means my office and workshops. To make matters worse it snowed heavily last night so I had to dig my way out this morning but at least the exercise warmed me up. Talking of warming me up I wish that I had the Taylor Heater that I had in one of my past boats.

 

Powered by diesel they use next to nothing fuel wise but they warmed the cabin up a treat. Many boaters find this type of heater old school and although not perhaps right for every boat, not least because you need a suitable bulkhead on which to mount them they do work a treat.You also might not need a heater if you only go boating in warm waters or the summer months.

    On all my boats I try to do without propane or gas of any sort, especially after I surveyed a steel boat that literally had the deck peeled back by a gas explosion, sadly killing the couple on board in the process. Gas also has other drawbacks especially up here in the northern latitudes where lower temperatures make gas appliances less efficient but the other drawback is that propane contains a high proportion of moisture. When the cabin is closed up against the cold lighting a gas stove to warm the interior up soon results in a dripping overhead as the already saturated air cannot absorb any more moisture. Problems are exacerbated if you cook with gas too and before long the cabin degenerates into a damp soggy mess. Of course gas has it's place but for me heating with diesel seems like a no brainer, cheaper than gas to operate, significantly less damp problems and I am using a fuel that I have 120 gallons of already under the floor.

    I would love to know other readers thoughts on the best way to heat the boat cabin if you go boating especially when the weather is less than clement.