Possibility of homebuilt plywood modern dinghy

[Muaddib1116]

I have no experience or expertise with building plywood boats, or building an wooden boats, or building any other type of boats, but I've seen some pretty incredible home built plywood boats online. As far as dinghies, the only wooden dinghies I've found are more traditionally styled sailing or rowing dinghies.

There's been a spate of pretty appealing modern hard dinghies in the last few years, the original being OC Tenders, followed up by ASTenders, and now UP Boats and Aspen Carbon Cats. Also a pretty cool looking aluminum tender from Godu boats.

The problem is that all of these come at a pretty hefty price, around twice the price of most aluminum RIBs.

Looking at the shape of most of them (the Aspen Carbon Cat might be too convoluted), it seems like a very similar boat could be built out of glass sheathed plywood. Obviously there would be a weight penalty, probably as much as twice the weight vs a carbon build, but I imagine that one could be built for less than a quarter the price.

I'm just curious what you guys think the viability of such a dinghy build would be, assuming someone could design some plans for one.

[rslifkin]

I don't see any reason why you couldn't do it. It could be done in foam cored glass as well. Depending on the hull shape you're targeting, foam core might be easier to work with (and could possibly be made lighter than plywood).

I've given some thought to a DIY dinghy build along those lines, just haven't actually done it.

[Muaddib1116]

That's what I've been thinking. If somebody put together some plans with templates for plywood/foam cutouts, I feel like it would be a fun project with a pretty useful end product.

[Spot]

I went so far as to buy some marine plywood for a dinghy, then ran out of time to build the dinghy for this season. The time was spent on other boating activities so I am not considering it a great loss.

Super simple:
https://hvartial.kapsi.fi/dinghy1/simboii.htm

A favorite:

https://www.youtube.com/watch?v=XDf3zkRpdk0

Another possible contender, met the designer this summer:
https://www.chase-small-craft.com/calico-skiff

[Muaddib1116]

Yeah, those seem to be pretty close to everything I've found so far, traditional sailing dinghies. I feel like a pretty good cruising dinghy could be built with similar techniques, just nobody has put together plans for one. Maybe I'm way off, but I feel like a good 10-12ft dinghy with similar capabilities to one of these modern hard dinghies could be built for less than a couple thousand dollars, if you were willing to put in the time and had the skills. There's so much criticism about how expensive good RIBs are, and even more about how much these modern hard dinghies cost, that I'm surprised that nobody has tried a diy version.

[Woody]

I looked at the examples you listed of "modern" dinghies and they seem to be made with some pretty complex hull forms. These are not designs that lend themselves to DIY plywood boatbuilding, at least for most people.






Not saying it can't be done, but production techniques that utilize molds allow mass reproduction. Building and fairing complicated shapes like that is a very laborious and time consuming process. Also, using plywood instead of solid carbon fiber/foam will increase the weight substantially, affecting the "performance" they are touting.


There's probably a middle ground to be had somewhere, but most people (like yourself) aren't boat builders and are better off sticking with simpler designs, at least for a first project. Even simpler shapes can be a good bit of work for novices.

What specific capabilities do these modern designs have that are most important to you? If you can identify those aspects of the design, maybe you can find a simpler design that will suffice.



By the time you buy the materials and put in the hours to build even a simple boat of similar quality, you might consider the cost of one of these very reasonable.


The old design mantra of picking two of Time, Money, or Quality comes to mind.

[Muaddib1116]

All true, but to be fair, the example you picked, the Aspen Carbon Cat, is the most convoluted hull shape by far, which I mentioned earlier. The OCTender and ASTender and UP Boats are much simpler hull shapes. They don't look any more complicated than most of the home built sailing dinghy designs I've seen.

[Leadfree]

Here ya go:

https://www.spiriteddesigns.com.au/ripple_tenders1

and you'll be able to brag you have a Schionning cat

[MicHughV]

I built my first dink out of plywood.
See attached.
Very simple to do.

[kenbo]

Dynamite Payson (H.H. Payson and Co.) has plans for boats that may fit your needs. I've built a few of his skiffs designed by Phil Bolger and they were very competent boats. He'll provide plans plus patterns for some boats.

[Muaddib1116]

Originally Posted by Leadfree

Here ya go:

https://www.spiriteddesigns.com.au/ripple_tenders1

and you'll be able to brag you have a Schionning cat

Oh, that looks pretty great! This design house is connected to Schionning?


The 3.6 looks the most interesting. Very narrow though, almost 2ft less width than the aspen carbon cat T11 or UP 340 or a Highfield CL340. I'm guessing you could request some custom changes though.

[MicHughV]

My dinghy plans came as part of the plans for my Roberts 38 build, but I know you can get a variety of dinghy designs from him.
Check out Bruce Roberts Design.

For that matter there are countless other dinghy designs online.

There will be something there for you.

Considering that at the time I built it, I barely knew which end of a hammer to hold, the design was simple and quick to build. It was small though, around 8', and I think around 11' length is really a minimum size for a dink.

[deblen]

Another source of plans & kits https://www.glen-l.com/?srsltid=AfmB...08VC9R7WvVQVdl


You can get many years of dinghy service from a painted plywood punt style dinghy.
Use good marine ply,stitch,tape & glass the seams. make it high freeboard & pram bow,for extra flotation. Paint well & regularly.
Use a fore & aft center seat for flexibility in passenger seating.
Cheers/Len

[MicHughV]

For my money, there is only one glue to use...which is the WEST system. It not only glues exceptional well, but can also be protection for the plywood.
Plus you can add all sorts of fillers for smooth chamfered joints, etc

If you are a belts and braces type of guy you can add a layer of fiberglass to help protect the plywood, this can also be glued on with the WEST glue.

[Woody]

Plywood doesn't like to be twisted or bent into compound curves. There are ways to create darts or curve thin panels gradually, so you might be able to approximate the simpler compound hull shapes. I've seen some beautiful work done with it, but there are limits.



As everyone here has been quick to point out, there are countless plywood dinghy designs available. Many here will testify that they can make excellent tenders. Lots to choose from depending on what you're looking for.



What I'm curious about is what design features specifically you're hoping to achieve.
Can you elaborate on what it is you're looking for in a dinghy, or what is attractive about the modern designs you shared?


The marketing around the examples you provided varies. One of the boats touts it's patented "hull form". Most of them are some lightweight composite construction (carbon, foam) and aiming to reduce weight and subsequent power requirements. Some have foam around the exterior. One company is promoting it's eco-friendly building practices, though it seems a little green-washy to me.



Whatever it is you're going for, I'm sure you can find a plywood design that will accommodate at least some of it. Even if you just want something that "looks" modern.



Your original question/statement was

I'm just curious what you guys think the viability of such a dinghy build would be

but it's not clear to me what design qualities you're referring to. If viable means "it floats and is useable", then I think it will be a success.



You want to build it in plywood.
You want it to be cheap.
You accept it will be heavier.
You accept the hull form will need to be simpler.


Outside of lighter materials and compound hull shapes, what will your new plywood boat design do that hasn't already been done?