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boats

The Stasha ‘Tweed’ Nesting Dinghy uses Flax

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The Woodenwidget Stasha ‘Tweed’ special edition lightweight nesting dinghy.

The Stasha lightweight nesting dinghy from Woodenwidget has been around now for a few years and I used the prototype for three years as my yacht’s tender. In many ways it’s the perfect dinghy for the Pacific Seacraft Dana, after all it was designed to fit on one! It is easy to stow and launch but more than that it is a fabulous little boat. It is a joy to row and it sails superbly too. When the prototype was showing signs of wear I thought about just putting a new skin on but in the end decided to do something a bit different. And so was born the Stasha ‘Tweed’

The biggest difference between a standard Stasha and the ‘Tweed’ is the fabric. The standard Stasha uses a thin and lightweight heat shrink Dacron covering which is then coated. The ‘Tweed’ uses a Flax fabric woven in the UK. It is specially woven so that it ‘drapes’ well and can conform to a curved surface such as a boat hull. It is normally used with a bio resin that cures with sunlight but I did not try this method deciding to use epoxy resin instead. Not because I think it is better or anything but simply because I had been given a load leftover from another job. If it wasn’t used it would soon be of no use so by using it I avoided buying something and stopped it being wasted.

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Close up of the cloth at the bows. It wasn’t even necessary to overlap the cloth leading to a very tidy look. The fine trim was added to cover the join between the cloth and the panel. This wasn’t entirely necessary as the join was fairly neat but it does lend a pleasant finished look and may even protect the bow panel from damage.

I will be discussing using this material later in this post but if you’re interested here is the link to the site where I bought the Flax fabric. It is the Hi-No twist fabric at £22-50 a metre. The roll is 1.38 m wide so for the Stasha it meant laying it across each section to get enough width to cover in one piece.

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Close up of the raw Flax fabric before epoxy.

One of the problems about using epoxy is that it is brittle and without modification would lead to a fabric covering that could be punctured too easily. In order to make the epoxy a little flexible you can add Benzyl Alcohol. About 2-3% is plenty. It’s a simple and cheap way to do it.

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The test bed for the fabric. This is the finish after the first coat of epoxy. As you can see the finish is very rough so needs sanding and further coats of epoxy.

The fabric is 400 grams a square metre which makes it twice as heavy as the Dacron before the epoxy is even added so using epoxied Flax is not a light option. However the standard Stasha proved to be so easy to stow and use on the boat that it wouldn’t really be a problem if it was a bit heavier. Especially considering that the boat is in two halves so it’s already easy to handle.

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This is how the fabric looks on the inside after epoxy. The finish is much smoother on the inside but far from flat and smooth.

The other difference between the original Stasha and the ‘Tweed’ is that it is made entirely of teak, not ash. Again, this was wood left over from another job and so it would be a shame not to use it. I didn’t know if it would be possible to bend the ribs using teak as it is a much stiffer wood than ash and not known for its flexibility or bending qualities but it wouldn’t hurt to try. If the worst came to the worst, I could always have ash ribs and teak stringers. That would have looked ok.

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Bending the teak ribs in required planning, patience and lots of spare wood. The extra stiffness of teak makes this a very hard job. Ultimately successful however. Wood is an amazing material.

As it happens making the ribs bend was certainly possible but required a lot of patience and spare pieces of wood as the breakage level was high. In a couple of areas I was not able to make ribs in one piece so had to scarf two pieces together. This was no problem but did add time to the build. The orientation of the grain was crucial as well, the slightest run off and the ribs would split. I soaked them before hand for a number of days and kept them wet while I was teasing them into place on the strong back with the hot air gun. It took a very long time to do the ribs and the teak was so much stiffer that the ribs would have a tendency to force the stringers away from the strong back. Ultimately I succeeded but it was not easy.

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One of the wooden rings cut out using two blades in the hole cutting saw. This was then cut into 4 and used to trim the plywood end grain.

Another difference is that every piece of plywood on the ‘Tweed’ has been capped with solid wood so that there is no end grain showing. This is a surprising amount of work, especially where the two sections join as the cutaway has rounded corners. The quickest way I have found to do this is to use two blades in a hole saw and cut out a ring of wood. This is then carefully split into 4 with the grain orientated and then it is glued to the plywood. One of the things that takes so long with adding trim to plywood is the care that you need when trimming it down level.

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Here the plywood end grain trim is being glued on. They will be planed down flush later.

The best approach here is to simply glue on a piece of trim that is slightly wider than the plywood. When it has set, use a hot air gun on the lowest setting, warm up the excess epoxy so it becomes soft and scrape it off using a sharp scraper. This is a very gentle operation. The epoxy will come off very easily with a little heat and a little patience. Once the epoxy is removed it is time to plane down the trim flush with the plywood. Remember that most plywoods have a top veneer of a half a mm or less. You cannot afford to cut into it at all. So a very sharp block plane is needed and also lots of care. Gradually plane down the trim until it is flush. Then use a block and some 180 sandpaper to clean it up.

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Gluing on the inner trim. This is something the standard Stasha in its never ending quest for weight loss never had. It adds a little weight but gives a very sleek look on the finished dinghy.

The last great difference is the addition of inner trim pieces to cover up where the stringers are glued into the end panels. It adds a ‘finished’ look to the boat and also strengthens the glue join. These take a long time to make and fit too as they need to be very neatly made. The quickest way I found was to make a cardboard template for each piece.

The seat used to scratch the varnish on the Stasha so now there are pieces of wood that will remain unvarnished instead. The seat is now made from slats of unvarnished teak rather than a single piece of plywood.

If you were thinking of building a Stasha ‘Tweed’ then I must warn you it’s a lot of work and it demands more skill than for a standard version which is very easy and fast to build. It will weigh about 50% more. With floors and seat it weighs about 17 kilos which is about 5 more than the standard boat but as I said, because it’s in two pieces not one section weighs more than ten kilos.

Asides from weighing a lot more it takes about three times longer to build and uses about five litres of epoxy and two litres of varnish!

The end result is a lightweight but virtually indestructible hard nesting dinghy. It is also extremely nice looking.

The finished fabric is almost two mm thick  so a rebate needs to be cut out of the exterior edges of the panels so that the fabric fits flush in the end.

Also, because of the extra thickness of the fabric it is necessary to remove a couple of mm from the sides of the joining panel on the rear section or it will be too wide to nest without scraping the varnish.

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The varnished front section with panels rebated a little to allow for the thickness of the fabric. The standard Stasha uses much thinner Dacron that doesn’t need to be rebated.

Here’s how the fabric is fitted: The fabric is not wide enough on the roll to fit from one gunwale to the other but it is wide enough to cover from front to back. I bought 4 metres of fabric and didn’t have much left over.

One of the great advantages of this system is that you do not have to rush or panic. You will epoxy only when you are happy with the fitted fabric. It is worth taking your time to get the fitting of the fabric correct because when it is epoxied and varnished it is translucent and any kinks or jumps in the weft or weave of the fabric will be very noticeable.

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The fabric draped over the framework, tensioned and stapled in place.

The fabric needs to be stretched tight before epoxying or it will sag with the weight of the resin. The problem is, how to get the fabric tight when it is such a loose weave. If you pull on one part, it pulls the weave out of line. I used staples to hold the fabric tight. It took a long time to pull it all tight while still keeping the weave straight along the keel. It took a lot of putting staples in and then pulling them out again as I tightened first one side, then the other all the time keeping tension fore and aft as well. This is quite tricky to do as you need as much tension as you can get but without pulling the weave apart or distorting or pulling the weave out of line.

However there is no rush so you can take as long as you like to get the fabric laying right. I found that the fabric lay well over the entire front section if I pulled the aft corners aft first. Then by the time I got to the front, the fabric was able to cover the whole shape in one piece without kinks or pleats. I was particularly impressed that I managed to get the fabric to follow the bow section without having to cut any fabric out.

To make working on the dinghy easier, I varnished the entire framework (except the outer surfaces) with three coats before fitting the cloth. Varnishing the framework is a complete pain in the arse, as is sanding between coats. The plan was to do three coats on the framework and then two entire coats inside making 5 coats for the woodwork and 2 coats for the fabric.

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This is what the front section of the dinghy looks like after its first coat of epoxy. The colour is good but the finish is very rough, far too rough for a boat. It will need sanding smooth and more epoxy then two coats of varnish before it is finished.

The epoxy is brushed on liberally. It is amazing how much epoxy the thick fabric will soak up. I did a test piece first to judge how to apply the epoxy. In the event it was very forgiving and I had no drops of epoxy come through the cloth despite a heavy application. The ideal is to have enough epoxy to wet out the fabric but not so much you are adding weight for no reason. The trick to getting the folded corners to stick down is to apply epoxy to the wood underneath it first, then dab the fabric down with more epoxy.

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The finish on the outside after three coats of sanded epoxy.

Once the epoxy is set it needs to be sanded smooth. If you have applied enough epoxy you will find that even with some quite violent sanding (I used 60 grit on a random orbital) you won’t go through to the cloth. In a couple of places the cloth was visible but that was OK as it needs another couple of coats, each one sanded down smooth. Then the whole surface was sanded down with 120, then 180 and finally 240 grit. Then it received a further two coats of varnish. The varnish is needed as otherwise the epoxy has no UV protection.

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Almost finished varnishing. Four coats on the wood and one on the cloth. It will receive one more coat all over. Note the trim around the stringers where they fit into the front panel. A small touch but makes a large difference to the looks. The epoxy used to glue in the ribs had teak dust blended into it to darken it making it very hard to see it.

The end result is a thick yet slightly flexible and extremely tough skin for the boat. It looks fantastic with the light coming through it. I am happy that I took so long laying the cloth so that the weave was even.

Conclusion:

Not for the faint hearted. Sanding epoxy is a thankless task and varnishing to that level is also soul destroying. If you have 120 plus hours spare then all you need is a set of Stasha plans from Woodenwidget.com and this article and you too can have a splendid looking lightweight nesting dinghy like the Stasha ‘Tweed’.

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View from the inside with the light coming through.

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Categories
boats

What is the perfect dinghy?

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OK, so that is a trick question because all dinghies are a compromise. In an ideal world we’d probably like a 4 metre rib with a 40 hp engine on the back that can carry 4 at high speed in the roughest weather. The reality is that a boat like this will be costly and impossible to use in the real world. I mean, for starters, where would you put it when it wasn’t being used?

Before you can decide which dinghy is best for you you’ll have a list of priorities. For example, here are a long list of features that are important. They are in no particular order. That is for you to decide.

Cost: Only you know how much you are willing to pay for a dinghy but remember that the more you pay, the more desirable your dinghy will be to thieves and the more upset you will be when it’s damaged or stolen.

Buoyancy: What will happen when your dinghy is swamped by waves and starts to fill with water? Will it stay afloat even with occupants? Of course buoyancy can be easily added at the cost of inconvenience. The best is built in buoyancy in the way of water tight compartments but having these adds weight and reduces options for storing.

Stability: Small boats are notoriously tippy and only careful use will keep them afloat. If you are light and nimble then this probably won’t matter to you but if not you will probably want something that is very stable such as an inflatable dinghy.

Stowage: It’s all very well having an 10 foot dinghy but only if you have somewhere to store it when not in use. A dinghy can be towed of course but when it gets rough it might become a liability, fill with water, flip over and sink or smash into the back of your yacht. The safest place to stow a dinghy is aboard the mother yacht be it in special davits, lashed to the deck or stowed below.

Rowing: Inflatable boats do not row well and this is why most owners also buy an outboard to go with it but outboards are noisy and smelly and pollute. They are heavy and hard to put on the dinghy and take up a lot of valuable stowage space. You will never offend anyone by rowing.

Sailing: Not all dinghies can sail, or be made to sail. Various attempts to make inflatables sail have been tried but the high drag, lack of lateral resistance and floppy structure makes the inflatable a poor sailor.

Outboards: They are costly, liable to theft, they can go wrong, take up space, pollute, make noise and smell. You may not need one if you buy something other than an inflatable.

Size: How many people do you need to carry? How able are they? How much do they weigh? Do you really want to carry all the extra weight of boat around for an occasional use? Would you be better with a smaller boat and make more trips to and from the shore?

Build your own: There are a lot of plans out there if you are the DIY type. This gives you the option of getting what you want although ultimately it may not be cheaper than buying a ready made boat.

So lets look in more detail at the options. First we’ll discuss the different types of dinghy and tenders available.

Inflatable beach toys: These are cheap inflatable boats with no safety features whatsoever. They are usually made of one continuous tube so if you get a hole in it, the entire boat will deflate and it will sink. They are not very tough and so easily damaged. They generally cannot take an outboard (petrol or electric) and will probably not have a decent system for attaching oars.

If you are in a warm environment and you never go more than a few metres from the mother ship and you can swim then a beach toy will get you to the shore and back. The reason why people buy them is because they are cheap. Generally a poor choice for a yacht tender.

PVC Inflatable dinghy: This is one up from a beach toy and will have at least two or more air chambers so that if the skin is punctured it will not sink. It will be made with a better quality, thicker skin that is more resistant. It may have the option to mount a small electric motor and will certainly have a system that allows it to be rowed.

They cost more than a beach toy and are generally no larger than 8 feet long. These are a bit safer than a beach toy but the PVC is relatively easily damaged and they will not be very resistant to damage from use or sunshine. Not a bad choice for a yacht tender as they are not expensive but far better to invest in a better quality inflatable made from Hypalon.

Hypalon inflatable dinghy: This is the most common choice of yacht tender. The Hypalon fabric is highly resistant to wear and UV damage. The boat will be made of several sections so will remain afloat even if one tube is punctured. They are very stable and good for heavy or clumsy people.

There are a host of advantages to inflatables which is probably why they are so popular as dinghies. They come with fabric floors, fabric floors with slats, inflatable floors or hard floors (RIBs)

They won’t damage the yacht when along side so they can be left in the water alongside the yacht. They can generally plane at speed with a big enough outboard. And of course they can be deflated for stowage although this takes some time. As does re-inflating them again later. A good pump is essential but even still, it can take a long time to pump it up. You can buy electric pumps which work well but are extremely loud and annoying.

On the down side, Inflatables are very heavy and hard to move about. Even deflated the smallest inflatable will be a bulky nuisance, either getting in the way on deck or struggling to stow it in a locker. This is probably why most people do not deflate them and either tow them or stow them on deck.

Towing an inflatable will cause drag and if the weather gets nasty it might even flip. Never tow an inflatable with a motor attached! If you decide to stow it on deck, you will have to get it there and most people use a halyard. In any case it’s almost always a two man job and when stowed on deck it’s likely to restrict vision and cause drag when sailing to windward or end up catching ropes and sheets. Not to mention restricting movement on deck. A complete pain in other words!

Inflatables are also very desirable to thieves because they are so common and they all look similar. They are not good to row and I have seen quite a few people get into trouble on windy days quite unable to get back to their yacht. This is why most are fitted with an outboard but then you are faced with the various problems that this brings, such as removal and storage on the boat, carrying yet another explosive fuel aboard not to mention the smell or the pollution and the fact that they can quite spoil an idyllic anchorage when there are dozens of them buzzing back and forth all day.

Sometimes it’s quicker to get the oars out and simply row to the shore but for some reason most owners just equate the inflatable with an outboard. I can’t tell you how many times I have seen a couple struggling to get the engine off the boat and onto the dinghy, then of course the engine won’t start or needs filling with fuel. It really would have been much less effort to paddle ashore!

Inflatable kayaks: Some people like kayaks for a dinghy and in some ways they are much better than an inflatable. Their more boat like shape means that they paddle well so you do not need an outboard. They deflate and stow easier too as they generally do not have solid floors to worry about.

Hard dinghies: The best bet from a performance point of view is always a hard dinghy. They are tough, usually have built in buoyancy (which can double as waterproof containers) row well and take an outboard. The down side is that they are heavy and hard to stow. If you use a dinghy a lot and have space for it, a hard dinghy is the best. It can also be converted to a sailing boat and that is excellent fun.

Nesting dinghies: This is a hard dinghy in two (or more) parts. The idea is that one half fits inside the other for stowing. This gives all the advantages of a solid dinghy but with a few more options for stowing. Some can be converted to sailing boats but they are generally heavier.

Folding dinghies: There are a lot of folding dinghies and if well engineered can be just as good as a hard dinghy. The downside of the folding dinghy is usually that it cannot have built in buoyancy so will rely on an external system such as buoyancy bags. Some can also sail. Often they are complicated and slow to assemble and have essential pieces which can get lost. They can also be very costly.

The best choice for me?

With the above information, you should be able to work out what kind of dinghy would best suit you and your situation. For example, if you want a dinghy that can sail, then you won’t be choosing an inflatable dinghy. If you want one that also rows, again the inflatable is not your best choice.

For me, the best dinghy that I could have would be a solid one because it can row and sail well. But the problem I have is where would I store such a dinghy aboard my boat? The answer is that I can’t! I have tried inflatables and while I appreciate their stability and buoyancy I do not like the fact that they don’t row well and can’t sail. Nor do I like their folded bulk or weight, nor their popularity with thieves!

What is best for me is a hard dinghy that can stow. So I am looking at either a nesting or a folding dinghy. Over the last 20 years I have tried all of the above suggestions and each has its good and bad points. It’s for you to decide which features you can live with and those you can live without.

After the basic fact that I have to be able to stow and deploy my dinghy easily, there’s no doubt that the ability to row and sail is high on my list of priorities as is stability. At the end of the day I have had the most success with folding dinghies. They just make so much sense.

 

Looking in detail as some of the choices of dinghy

The Inflatable Dinghy

The inflatable is the most common form of tender. There are many reasons for this as we have already discussed but one of the main reasons for their popularity probably has to do with cost and availability. The market is saturated with models from many different companies, there’s so much competition that prices are kept generally low and you will find inflatables for sale in every ship chandlers the world over.

Prices start from about 300€ which is about as cheap as any dinghy on the market but because they do not row well and cannot generally sail one must also cost in the price of an outboard engine. Even the smallest outboard engine will cost at least 400€. Then you must ask yourself where will you store the outboard when it is not in use? You may have a locker you can put it in but outboards are smelly things and the smell can end up penetrating the rest of the boat which is not pleasant. Many people fit a bracket to the pushpit at the stern where the outboard is stowed. This will mean the addition of a bracket (and more cost) plus the outboard will be always out in the elements which will quickly degrade it and lower its value. You can of course get a cover made but again this all adds to the cost.

The outboard on a bracket also adds weight and windage where you don’t want it. It might even get in the way. It is also vulnerable to theft and makes the boat look fussy. It will certainly need a lock to deter thieves but unfortunately a lock will not stop a determined thief.

Blowing up and deflating an inflatable is a miserable experience. Most dinghies come with a foot pump but they are very annoying to use and it can take as much as 20 minutes to inflate even the smallest boat with one. They are also very badly made and generally break or leak after a very short time. An inflatable boat that cannot be inflated is as useful as a chocolate fireguard!

There are other options of course. The hand operated pumps that you stand on are a much better way to inflate a dinghy but again, it’s more cost and they are quite bulky. Or you can buy an electric inflator but they cost and need power and worst of all are extremely noisy. Making this kind of noise in a peaceful anchorage will not endear you to your neighbours.

Inflatables are generally pretty tough and hard wearing but they don’t like to be left out in the sun. Being regularly folded also puts creases in the fabric which in time can cause leaks. The most common problem with inflatables is that the transom comes unglued. Small holes can be repaired easily with a patch and there are products that can fix quite big tears with a clamping system.

So I think you can see that the inflatable seems like a good idea at first but once you consider the realities and extra costs and hassle involved you might want to think again. If you can leave the dinghy inflated at all times with the engine fitted then the inflatable makes a lot of sense but not many boats are big enough to allow this.

The cheaper inflatables have a simple rubber floor which is very flexible and very annoying because it is always moving. When water gets in (as it will) you will get wet feet as the weight of your body will always create a low spot where water runs to.

The next step up is a slatted floor. This adds cost and complexity and makes the stowed package a bit more bulky and heavy. It is still far from ideal as you will still have your feet in water. The nest step up from slats is an inflatable floor. This works very well giving the boat good stiffness and it also means that you have a chance of keeping your feet dry. The down side is that it adds weight and takes longer to inflate. An inflatable floor adds cost too.

The ultimate inflatable is the RIB (rigid inflatable boat) which is basically a narrow hard dinghy with inflatable sides. Obviously these are heavier, more costly and do not roll up although the sides can be deflated to reduce its size a little. They offer the best performance of all inflatables.

There is one last kind of small RIB that needs a mention, it’s a jet boat, a sort of mix between a RIB and a Jetski and I for one have never understood why anyone would buy one. They have an inboard engine which takes up loads of interior volume and are hopeless to manoeuvre. They are noisy and smelly and expensive and heavy and frankly make a very poor tender for any yacht.

 

The Hard dinghy

The hard dinghy is the best performer of all the dinghies you can have. They can be rowed, sailed, motored or even sculled along. They are tough and much better looking (generally) than inflatables and can be painted to match the mother ship. They are most often made in wood, ply, alloy, plastic or grp.

The biggest problem with a hard dinghy is that they are heavy and bulky in as much that they do not reduce in any way for stowing. Some hard dinghies can be modified in shape to fit on a certain place on deck. If you have space you can maybe store the dinghy inverted on the cabin top. The bigger boats store them upright and stow things in it and then use a cover to stop water getting in. Stowing the dinghy the right way up makes it quicker to deploy.

If there is no room on deck then you may be able to use davits. These are basically arms normally attached right at the back of the boat that are used to easily lift the dinghy out of the water even with an engine still fitted. It is a quick and easy system that often uses a purchase to make lifting the weight easier.

The problem with davits are many fold however. All that ease comes at a price. Firstly the davits will need to be attached to the boat. Because of the weight and leverage involved they will not only have to be strong but more importantly so will the boat where they are bolted on. It is entirely possible that the boat will need to be reinforced before davits can be used. This obviously adds cost and weight.

Once the davits are in place you will then discover that your rearward visibility has been seriously compromised. This is more than just an inconvenience, it is also potentially dangerous as you are just as likely to get run down from behind as anywhere else! Also if you moor stern to, such as in the Med a dinghy in davits off the stern will mean you will have no choice but to moor bows to.

The boat’s sailing performance will also be seriously hampered by a dinghy in davits, not only is that a fair bit of weight very poorly placed high up and right at the stern but it will create a lot of drag, no problem if you are always running downwind but as we all know reality just ain’t like that.

There is also a chance that the boat and the dinghy can be damaged by wave action as the boat is completely vulnerable stuck out the back as it is. A dinghy in davits must be very well attached and tied up to the davits so that it cannot move under any circumstances but it will also need a cover to keep water out.

The last point is that if you do have a problem with the dinghy in davits you might find yourself hanging out over the back of the boat to deal with the problem. This is not very wise and quite dangerous.

So as you can see, the main problem with a hard dinghy is where to put it when it’s not in use. Hard dinghies are available to buy ready made, in kit form or available for home build from plans.

 

Nesting dinghies

Nesting dinghies share most of the attributes of a hard dinghy but with the advantage that they can be effectively cut in two and stowed one half inside the other to reduce their size. They are probably going to be somewhat heavier than a standard hard dinghy as they have a join which tends to add complication and weight.

Sometimes the shape of the dinghy is compromised by the nesting action. Generally the bow section is made to fit into the stern section but this sometimes leads to a compromise bow shape that lacks buoyancy and reduces interior volume.

One of the biggest problems with nesting dinghies is the rowing position which is often logically placed above the join but is often too far forward. It may work fine with two occupants but it may be very bows down when rowing alone. It’s a small detail but where you sit when rowing in a small boat makes a fantastic difference to the way it rows.

Sometimes nesting dinghies can be somewhat complicated to assemble and it may not be possible to assemble the boat in the water. If this is the case, the dinghy cannot be launched easily in two halves so you will have to struggle with the weight of the complete boat.

Obviously nesting dinghies will be more costly than an ordinary hard dinghy. But if you insist on a hard dinghy but don’t have much space perhaps a nesting dinghy is the way to go. Even if it cannot be assembled in the water it will probably still be faster to assemble and launch than it would be to inflate and launch an inflatable dinghy.

Most nesting dinghies have some kind of built in buoyancy which is safe but reduces interior volume and adds weight.

Nesting dinghies are available to buy ready made, in kit form or available for home build from plans.

 

Folding dinghies

Ever since Noah, people have been looking for the perfect dinghy, one that does everything a good dinghy should do but weighs very little and packs away easily to a small package. In some respects folding dinghies are the closest mankind has ever come to this utopian dream. Not surprisingly there is a large choice of folding dinghies made from many different materials.

There are many designs to choose from some made of wood or alloy, some with a framework and a canvas type of material. The more solid versions are often heavy and take some time to assemble with many parts needed which make them difficult to assemble on the limited space of a yacht deck.

There are so many different types of folding dinghy that it is hard to generalise. Some can sail, some can take an engine, some can plane, some are extremely tough, others less so. Some can be assembled in moments, others take a bit longer. What they all share is the ability to reduce in size massively to make stowage easier. Most folding dinghies row well and certainly better than any inflatable.

Some folding dinghies are very tough but if they are tough it means that they are heavy. The lighter versions use a fabric that is similar to an inflatable and can be damaged through misuse but like the inflatable they can be quickly and easily repaired if holed.

Folding dinghies do not have built in buoyancy although they may float depending on the material they are made of. However it is easy enough to add buoyancy bags although this does make assembling them take a bit longer.

They are available to buy off the shelf, in kit form or even for home build from plans.

 

Looking at some available dinghies

 

Inflatable dinghies

Inflatables are available to buy anywhere in the world and the choice of boat is enormous. Generally they are all similar in shape, colour and ability but with differences in quality and details. Some of them are very high tech

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This is a typical inflatable boat. This one has slatted floors which offer some rigidity to the floor but not too much weight. It also allows the boat to be easily rolled up. Often inflatables have the oars always attached but more often than not the oars are not of a good quality. One of the reasons why an inflatable rows so badly is because the oars are too short.

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This is an inflatable boat with an inflatable floor. It makes for a much stiffer boat and it’s possible to keep your feet dry. The bulkiness of the floor (even deflated) makes the boat more bulky and heavy when rolled. If you add one feature, you lose another. This is true for all boats.

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Here is the classic Avon Redcrest. It’s been around for decades and has a dedicated following. What makes it different from most inflatables is that it has a rounded shape at the stern. The problem with this is that although you can add an outboard the force of the engine makes the tubes move and the motor can flop about. That is why most inflatables have pointed ends so that a solid wooden transom can be fitted.

Hard dinghies

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The clever Walker Bay range of hard dinghies. Made from super tough moulded plastic and easily converted to a sailing dinghy. The only real problem with hard dinghies is where to stow them. Even an 8 foot hard dinghy will be too hard to stow and lift aboard most cruising yachts.

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The Elterwater Pram dinghy. These can be built from plans or you can buy a kit of ready made pieces to glue together. Available from Fyne boat Kits.

There are a huge amount of hard dinghies available on the market in all shapes and sizes made from any number of materials. Most will row well and some can be sailed. If you have space and don’t mind the weight then a hard dinghy may be for you.

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For those who insist on a hard dinghy there is the Woodenwidget Deckster with its removable front section that allows it to be stowed around a mast. Even though the Deckster can be nicely stowed it still shares all the other issues that hard dinghies have such as being heavy and reducing forward visibility. It does however row, sail and motor and can even use the revolutionary Hobie Mirage drive.

Nesting dinghies

 

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This is a true hard dinghy but it comes in two pieces. One side nests inside the other. nesting dinghies share all of the issues with hard dinghies but often have additional issues. Sometimes the hull shape is compromised to allow one side to nest inside the other. The join adds complexity and weight. Nesting boats cannot always be assembled in the water. This one comes from Nestaway who have an impressive range of nesting boats. The weight of this boat is about 50 kilos which doesn’t sound much until you try and move it about.

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The Woodenwidget Stasha. The lightest nesting dinghy in the world. At just ten kilos it’s child’s play to move around. Made from an ash framework then covered with heat shrink Dacron it rows, motors and even sails extremely well.

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The Woodenwidget Stasha nested. The Stasha is unusual for two reasons, one; it can be assembled in moments either ashore or afloat and it’s the rear section which nests inside from front section. This makes for a much less compromised hull shape and a more balanced rowing position.

 

Folding dinghies

 

There is a huge range of folding dinghies. Some, like the Seahopper are more like hard dinghies that fold. Others like the Woodenwidget Fliptail are super lightweight for ease of use.

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The beautifully made Seahopper folding boat. This is like a hard dinghy that can fold though it must be said it is fairly longwinded and complicated to assemble and there are many pieces involved as you can see from the pic below.

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A great folding boat though a bit complicated but if you want a folding boat that behaves like a hard dinghy then this would be ideal.

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Here’s the Flapdoodle folding dinghy which can be built from plans.

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This is the Porta-Bote a polypropylene folding boat. It looks a bit strange but has sold in the thousands over many years. Super tough and light but it still has extra pieces that need to be put in place. Not the cheapest folding boat available but it is quality.

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Here is the classic Woodenwidget Origami folding dinghy. They don’t come much more simple than this. Available in two sizes (6’ & 8’) they are available in plan form only but the boat is so simple to make and the plans so comprehensive that almost anyone can build themselves one. They might look a bit box like but they are surprisingly stable and work very well indeed.

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Here is the Origami 6 when folded. At just 15 kilos it’s one of the lightest folding boats you can find. It has built in carry handles so is very easy to carry.

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Here is the Woodenwidget Fliptail 6 and 7 foot versions. Like all Woodenwidget designs they row, motor and sail. Pretty, light, stable, tough, easy to assemble with no extra parts to forget (all pieces needed to erect the dinghy are always attached to the boat) the Fliptail has to be one of the most versatile folding boats in the world. Available to build from plans.

So there you are. I hope a fairly comprehensive explanation about the compromises one has to make when choosing a dinghy and a basic oversight into what is available on the market. I hope it has been of help to you

Categories
boats

Designing the lightest nesting dinghy in the world

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Panasonic Lumix. The Stasha, the world’s lightest nesting dinghy. Weighs as much as a baby bird (wandering albatross chick)

There’s a saying that I like. ‘If you get in a car and don’t know where you’re going, you’ll never get there’. Designing a boat is a bit like this as you need to know a few things before you can begin. Knowing where to start is easier said than done. So many things can influence the design. I have found that a good place to start is to first think about what you don’t want. For example, I didn’t want a heavy dinghy. Nothing spoils the dinghy experience more than a weighty tender that is hard to move about and stow. This was my starting point. No matter what shape or size of dinghy I came up with it wouldn’t be a heavy one!

For years, I’d been intrigued by boats I’d seen in America that were made using materials from light aircraft. Constructed from a framework of wood and covered in cloth, they looked fragile but were obviously quite tough and since I was determined to keep the weight down I would also have to employ a similar system. So deciding what I didn’t want from my dinghy led me to the construction technique I was going to use.

However, there’s no point having a light dinghy if you have no where to put it. My yacht is just 24 feet long and the only place I could think of to stow a dinghy where it wouldn’t be in the way, look ugly or be unseaworthy was on the tiny foredeck. I got my tape measure out and discovered that it was about 4 feet wide at the aft end where the cabin begins and was a bit more than 4 feet from there to the bows. So it would have to be a nesting dinghy. In theory it could be about 7 feet long when assembled and that was a good size for a small yacht. And so was born the idea of making a super lightweight nesting dinghy.

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Leica M9, 21mm f2.8 Asph. Stasha dinghy, nested and stowed on the deck of a Pacific Seacraft Dana 24.

There’s not much point worrying about aesthetics when you are designing a dinghy, the most important thing in my opinion is stability. There is nothing worse than a tippy dinghy, except perhaps a heavy tippy dinghy. Light boats are less stable than heavy boats so I would be relying mainly on the shape of the boat to provide stability. This meant that it had to be as square as possible. I now had enough information to design the boat’s shape.

The rest of it would be guesswork based on experience. What would happen if I cut a boat in half to make it nest? Would it be strong enough? What kind of forces would the join be under? How would the stringers attach to the end panels? These and many more questions filled my brain. As far as I could tell, no one had ever built a dinghy like this and I wondered why. Have people tried it but drowned during testing or has no one ever tried? Maybe it was a stupid idea that would never work but one of the great beauties of a lightweight boat is that they are cheap to build. Less materials means less cost. I could afford to simply make a boat and see if it worked.

Normally nesting dinghies are made so that the front section comes off and fits inside the rear section but this does not seem logical to me for many reasons. The shape of the front section always needs to be quite pointed but this reduces stability too much. It also means that the interior volume of the dinghy is much reduced so you might have an eight foot nesting dinghy but it will feel much smaller. Then there’s the rowing position. It’s perfectly logical to put a thwart on or above the join but it leads to a bows down attitude when rowing which makes the dinghy hard to row and just looks wrong. Rowing is easier when the bows are slightly up.

The whole concept seemed flawed to me so I tried a bit of lateral thinking and did some sketches with the rear section fitting into the front section and suddenly everything started to make more sense. The most obvious problem with doing it this way around was that the rear section would be slightly narrower than the front which would mean a step where they join. In fact this is not a problem as the bottom of the dinghy remains flush, it’s just the sides that have a small step. I doubted if it would make an appreciable difference to the finished boat’s performance.

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Leica M9, 21mm f2.8 Asph. Sunlight glows through the translucent skin of the Stasha. Note the small step at the join.

This one compromise seemed a small price to pay for the host of advantages that it brought the design. I could have a fairly fine bow, a good interior volume, great stability and a perfect rowing position. Another bonus with this set up is that the rowing position doesn’t have to change when you take a passenger. Not only this but if the passenger sits in the front section back to back with the rower, the combined weight is centred in the boat increasing stability still further and each occupant has a clear, unobstructed view of their surroundings. This is much more pleasant for everyone. Yet another advantage was the fact that the pintles for the rudder are stowed inside the nested boat so ropes can’t get caught on them.

To simplify the building process, I decided to do away with any hint of sheer and make the top of the boat completely straight. Simplifying the wood requirements would also make the boat easier and cheaper to build. Now I had all the information I needed to start to design the boat. I made a few sketches just to see how it would look. Although it was boxy it still had a nice boat like shape which was pleasing.

Next I made a 1 -10 scale cardboard model 220mm long. I wanted a near flat bottom for maximum stability and ease of build but I suspected that the fine framework allied with the pressure of the water on the hull would flex inwards so I incorporated a slight V into the bottom. This would also add more strength to the structure. The sides are almost upright, with only a slight angle outwards. Again, this increases interior volume and stability.

The simplest way to build a boat like this is to make a jig. Panels are cut out and screwed to the jig and then the stringers and ribs are attached to it to create the framework. Happy with my cardboard model I divided it up into 5 sections and used these measurements to make the stations that would dictate it’s shape. I scaled up the measurements by simply adding a zero. Then these measurements were converted into instructions using the simple ‘join the dots’ principal that all Woodenwidget dinghies are built with.

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Leica M9, 21m f2.8 Asph. This photo shows the jig for the front section with all panels, stringers and ribs in place.

Deciding how many stringers and ribs to use was decided by guesswork based on experience and finally what ‘looks right’ while trying to minimise weight and keep the build simple. Obviously the more ribs you have the more work there is to make and fit them. Since lack of weight was everything I did err on the light side.

The end panels on the jig stay as part of the boat while the inner stations are only temporary. The end panels have slots cut in them to accommodate the stringers which are then glued in with epoxy resin. The stringers are held in place on the inner stations with cable ties. The following day the ribs are made and glued in place. The ribs are glued everywhere they touch a stringer. This gives over 60 glue joins which makes for a surprisingly strong structure.

The making of the ribs caused me some concern. On the one hand I wanted the dinghy to be easy to build but it had to be light too. I considered a system that had no bent ribs but it meant making nearly 40 mortices which would take a long time and require a certain skill. It would also add weight and complication. So I decided to take a fresh look at bending ribs with heat.

At some point most boat builders will have a go at steaming wood. It’s a lot of fun and it’s amazing what you can put a piece of wood through before it breaks. If you want to really understand wood this is a great way to do it. You will walk away with a new respect for it as a material.

Some woods bend easier than others so I chose ash because it is strong and light as well as easy to bend. The straightness and orientation of the grain plays a big part in how far you can bend wood as does the amount of moisture content. Thin wood bends easier than thick wood but in any case you’ll need heat. Most boat builders will construct a steam box to do this but since there are only 9 ribs to be bent in the Stasha I needed to find a simpler way.

Pre soaking the wood for a couple of days is essential. Once the wood is completely saturated, they are fitted to the jig. The centre is clamped to the keel and each side of the rib is pushed down while applying heat from a hot air gun. The ribs are pushed down in gradual stages until they touch at all the stringers. This is a little time consuming and it helps to have patience but still easier than any other system I could devise. It’s also the lightest way and gives the dinghy a nice rounded boat shape. This also makes it easier to fit the cloth later.

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Leica M9, 21mm f2.8 Asph. This shot shows one of the ribs being gradually persuaded into place with heat from a hot air gun.

The ribs are then glued where they touch at all the stringers. A day later the structure can be removed from the jig. It’s still quite floppy but gets much stronger at every stage. (To save wood, the stations are cut down to make the jig for the rear section of the dinghy). Inner gunwales and reinforcing knees are added for strength and that’s basically all there is to the wooden structure. Not one screw in it. It’s thanks to the amazing bonding strength of epoxy that a construction so light is even possible.

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Leica M9, 21mm f2.8 Asph. Here’s the framework for the front section complete, just awaiting the kevlar twine and the cloth.

Now all the hard and messy work is done. All that remains is to cover the framework with a special heat shrink Dacron cloth. It’s attached with a product called Heat’n’Bond which is glue on a roll. It is melted with a humble domestic iron. This is cheap, light and very easy to use. It also sticks very well to the cloth and has excellent sheer force qualities. This Heat’n’Bond tape is applied to the keel, gunwales and end panels.

Now Kevlar twine is laid diagonally across the boat and glued to the gunwales. This helps to reduce twist in the structure and also to give more for the cloth to lay against than just the stringers. The cloth is laid on the structure and glued to the gunwales and end panels, then the iron is run over the cloth and all the wrinkles and baggy bits simply disappear leaving a drum tight smooth finish. This is very satisfying to do. The edges of the cloth are protected by small battens of wood and finally coated with a water based varnish but this is just one way to waterproof the fabric.

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Leica M9, 21mm f2.8 Asph. Here the Dacron cloth has been glued in place. The remaining creases magically disappear when the iron is run over it.

Having made the two halves it was time to work out a way to join them. There’s no point having a nesting dinghy if it can’t be easily assembled either on land or on the water. Initially I thought about a very minimal bulkhead for the join along with some kind of waterproofing but that hardly seemed easy. Far better to sacrifice a little weight and have fuller, higher bulkheads. This means that each section is a boat in it’s own right so there is no need to waterproof the join at all. Two simple keyhole slots are all that is needed at the bottom of the join and two bolts at the top. Assembly takes less than a minute.

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Leica M9, 21mm f2.8 Asph. Here the keyhole slot for joining the two sections can be seen.

What we have here is a basic 7 foot nesting rowing boat which is probably fine for most people especially as it rows so well but I also wanted it to sail. Because the rear section nests in the front section, centreboards and the like are out of the question and in any case fitting something like that would add weight and the potential for leaks. It would also be demanding to do and this doesn’t fit in with the easy build ethos.

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The keel is bolted to the side of the boat and can swing up if you run aground. Here the slab sides are a bonus as it gives somewhere to attach the keel lower down. The mast support is made from two thwarts, the upper one bolts to the top of the gunwales and the lower one rests between the ribs below it. Diagonals of string must be added to help spread the load from the mast. Simple, effective and light. The mast and rudder from an Optimist is used with a slightly cut down sail.

If you want an outboard then you’ll have to reinforce and thicken the transom. This adds about half a kilo to the weight of the boat. This option has also been designed to be retro fitted at any time.

I am delighted with how well the boat has turned out. It is pretty, very light, easy to assemble, stows beautifully and fairly unobtrusively on the foredeck. The rowing position is excellent and very comfy. It goes fine with up to a 3.3hp outboard and sails surprisingly well with it’s modified Optimist rig.

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Panasonic Lumix. The Stasha under sail using it’s cut down Optimist rig.

To be honest, I have been surprised at how well this boat works. I had no idea if it could take the stresses from a mast and keel or an engine but it has passed all these tests with flying colours and I’m still here to talk about it. Someone said it seems to ‘Dance on the water’ and it really does. It also slips along and carries it’s way amazingly well for such a light dinghy. Any doubts I might have had about the step in the hull are long forgotten, it seems to make no difference whatsoever. This can be confirmed by watching the water through the translucent hull as it passes the step. The boat hardly leaves a mark of it’s passing as it cuts through the water.

So this proves that if you follow sound basic small boat principals and keep faith with your original wants and don’t wants, you end up with a splendid little boat that is easy and fun to build in the smallest of places. It’s cheap to make and surprisingly tough. It stows away in a minute almost anywhere, including the back of an estate car. It rows well, sails well, takes an engine, two people with shopping and it does all this while weighing the same as a Wandering Albatross chick! (about 10 kilos! Very heavy for a baby bird perhaps but extremely light for a 7 foot dinghy)

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Panasonic Lumix. The Stasha nested. It can be stowed upright if needed. Note the kevlar twine reinforcements.

Visit www.woodenwidget.com to see more videos and to learn about their clever range of build yourself dinghies for the spatially challenged.

To learn more and see some videos of the Stasha in action, please visit Woodenwidget.com