Arne wrote: "However, no method beats plastic when it comes to stamping out dinghies, these days."

I still think ply is bettere than fibreglass for a dingy, Arne. For "stamping out" perhaps fibreglass suits production better, but not for using. A good dinghy is a light dinghy. Plywood dinghies can be and should be light.

Any fibreglass dinghy I have had (and I still have one that the grand kids fool around in occasionally) has been nice and durable, but too heavy to be convenient.

Would have been interesting if there had been a stipulation that the tender had to be built on a beach with only hand tools that were carried on the mothership (I know of one such case). Different designs would have resulted.

Would have been interesting if [insert theoretical stipulation here]...

But there were no such stipulations. Only loose guidance.

How far back would you like to wind the clock, Jan? Is pre-21st century far enough, so as to preclude modern, fast, efficient ply boatbuilding methods? Or must we go back to pre-20th century methods, and fell trees and cut and shape planks with axe, handsaw and adze? 

Thank You very much, these pdfs are perfect an in the meantime I found out that the company where I bought my first class Okoume marine plywood sheets can cut them with your DXF files. I am just waiting how much that will cost before I have it done and save myself a lot of plotting by hand.

Hi David, Quite easy to make your tender to Sibling with the slots provided to put it together. I do have LibreCAD on my PC but I am hopeless in using it. Is there an easy way to find out the dimensions from the dxf files ? I tried with the dimension tool from one point to another but this is tedious. Earlier on you uploaded besides the dxf files also JPG and PDF formats of the three plywood panels which I could easily print on my A4 printer. I wonder if I have some scale of a nested panel ( 250 x 125 cm ) it should fit onto 6 A4 pages in poster mode printing. I am keen on getting the dimensions which I then could plot by hand onto the plywood panels. Maybe You can give me some hints.

Here is the draft of Page One

Boatbuilding (in plywood) for dummies .
(..by one of them..)

The thought of building a dinghy for oneself is both tempting and scary. I write this mainly to encourage myself to do it. I have drawn a few small pram-type dinghies (like Halibut, Medium Boy and Buddy), which are meant to make the threshold for getting started as low as possible. At the same time, I want the boats to be good, not just floating boxes.

I have done my best to design out difficulties when building.
Here are some key elements of the boatbuilding for dummies:

• ·         The designs are pram types with constant flare in the sides, both on 3-plank and 5-plank designs. This ensures that any bulkhead or frame can be made without any curves in them, meaning much faster construction and fitting.
• ·         The boats are built right side up, using three female, or cradle type moulds, plus the bow- and stern transom. The moulds, from plywood, chipboard, MDF or whatever are solidly fastened and aligned to a backbone plank, say 50 x 200mm and a bit longer than the boat. The bottom and side planks are screwed to the mould with thin, temporary screws. 
• Now the bottom and sides can be glued together ( see details on this  -  I prefer using polyurethane glue over epoxy). If needed, a few ‘stitches’ may be added to align the planks perfectly between the moulds. Hopefully I get away with duct tape.
• ·         Then the transoms. I will fit them ‘inside’ the hull, so the skin thickness has to be counted with when making them.
• ·         An important element is the use of a number of single elbow frames, just glued in place. The use of these will simplify building hugely, but will still ensure a strong and stable boat. Since the flare of the sides is constant, one may make one template for these elbows, which will speed up production of all the frames.
• ·         With the frames in place, one is free to install whatever one wants inside. With no inner moulds in the way, one may try thwart type, thwart positions and heights, as well as suitable positions for oarlocks. One can even step on-board and ‘test-row’ the boat.
• ·         Before releasing the boat from the cradle, one may then paint the inside, or one may wait until later. My boat is meant to rest upside down between use, so the inside will only be given ordinary paint after slopping on some thin preservative oil.
• ·         With the boat released from the moulds, it is turned upside down, the screw holes are dealt with and the chines rounded off a bit, prior to glassing the bottom. I may even add an extra 300mm wide strip of plywood along the centreline, to beef up the bottom before glassing.
• ·         A pair of skegs can then be fitted, if wanted.

Then paint, launch and row...

Well, that is the idea, so far  -  I bet it will be adjusted after having gained hands-on experience...

Arne

A planned small-scale test: