Knees, knuckles and bums...

 The hull after I had lifted it off the formers and ladder.

Because the brass screws exited the transom, I used an angle grinder to grind them flat on the inside and on the outside

to measure up the 'knees' for the corners, I started with pieces of 19mm DAR "Tasmanian Oak", and used a crude offset pencil to rough out the angle between the bow and the sides.

After cutting bevels for the two sides in contact with the boat, I had a piece that fitted.

I marked out the "knees" from measurements on the plans, drew a freehand curve, then cut with a jigsaw. These came up better than I expected.

Preparation for painting consisted of sanding back some of the worst overspills of epoxy...in hindsight, I should have taken the sanding of the spilled epoxy further, to ensure a good paint finish. (The orbital sander seemed to have the remarkable property of grinding off the epoxy before chewing through the plywood - perhaps because the epoxy is so rigid?)

 I used a belt sander on the bigger dribbles of epoxy - no finesse there - epoxy and plywood are ground to dust equally!

Paint hides faults very poorly!

Planking, bevelling and screwing

Late Oct:  well, after a layoff period to recover from a back sprain (blunt planes and lower back injuries do not mix) I purchased myself a cordless electric plane and I'm back to planking.



- better to use as few screws as possible to hold it together in the dry fit - after all, it is the epoxy that will be holding it together not the screws
- i bought brass screws, but silicon bronze screws would have been much cooler, especially since you don't need so many anyway (or at least, I don't think you do - I don't actually know where all those hundreds of screws are meant to go without the book!)

-

Don't add a dozen screws like I did!

the bevelling is reasonably important to ensure the planks sit nicely against each other, dont be in too much of a hurry with the plane - I've been planing off fractions of a mm, then checking to see how it looks.

The bevel angle will allow the next plank to sit ~ flush. Epoxy will make up the difference.

First off I would say I've learnt a few things in the last few weeks:
- the accuracy of the laminated rib and temporary plywood moulds is really important
- the planks are shaped assuming the moulds are accurate, so lay them against the drawings, and trim and/or add until they ARE accurate
- I pulled my dry fit planking apart, pulled off the moulds, and started trimming once I saw where being sloppy was going to lead me

I'm going to have a lot of screw holes to putty up when I finish!

holding down roughly with clamps, tapping into place then using a countersink bit, an 8G by 25mm brass screw and an impact driver seemed to work pretty well, even without any help!

While recuperating, I made some short 'saw horses' - I would be ashamed to admit it took me three goes to get this right on any other forum!

Showing the shape of the 'boat' with the three planks fitted on one side.

Showing the fit of the planks to the laminated rib, on the inside, once I had spent 2-3 hours pulling it all apart and planing the rib down to proper, accurate size (actually it is only accurate on the outside, it is actually more skinny than the original, but the inside curve doesn't matter.

Oct 2014:
As Ive got to the point of placing and fixing the plywood bottom and sides to the temporary frame, I realised that I really should have bought that book that was reccomended on Amazon..."How to build the Nutshell pram" !  I have no idea how all the screws and bits of wood fit together . I had naively assumed the paper plans would have all that.

Back down to Whitworth Marine in Caringbah with a sheet of the plans annotating all the screws I needed, provided welcome distraction for the older boatbuilders there who crowded around to have a look at what was being attempted, as well as comments from the younger guys along the lines of how much more useful the dinghy would be with a 30hp outboard affixed!!

Back to Google, 
and I must also mention here how useful other blogs have been for me, notably:
 -- Building Our Nutshell Pram by BZ on   "nutshellpram.blogspot.com.au"


and now looking at the photos on this blog to see where the screws go!
 -- Nutshell Pram Construction by Shutterfly at nutshellpramconstruction.shutterfly.com


NUTSHELL BOTTOM DRY FIT:
First off, I added bracing to the temporary moulds to take the strain of the bent plywood, and also an extra batten to straighten up the laminated mid frame.

Next was to dry fit the plywood bottom, drilling holes for the Record clamps to pull down the plywood to the moulds.

(note; remember, spade bits don't like 10G steel wood screws!...scratch one 22mm spade bit:)  

The bottom didn't seem to line up exactly with the moulds, so I added the mid plank on one side as another guide. Again, I drilled holes in the temporary moulds with a spadebit for the clamps. Not wanting to drill large holes through the stern and bow transoms, I setup an easy windlass to pull the plywood down to the bevelled transoms.

Its starting to show its final shapes, but I have a bit of adjusting to do before I screw down the ply bottom. It's been hot enough to burn outside today, so this will have to wait for more afternoon shade....

'Shark Bait Pete'

Starting this blog to help any other amateurs out there build the Joel White 'nutshell pram'. Note I am not a woodworker, or have a trade, but I've made a hobby of woodwork and I've got quite a good few tools.

Dec 2013: looking for something to do next and, after a brief foray into rubber band powered planes , decided to build a small wooden boat for fun, and to eventually get the boys out of the house.

Constraints included a small back yard, small shed, limited side access, and no garage. The boat had to fit in or on the family car (Kia Carnival with builtin roof racks) as I have no room for a caravan. It had to be light enough that two could lift it onto the car roof racks, and not damage the roof racks as well.

2014: With Google as my friend, I soon found the 7' 7" Nutshell pram and liked Joel White's design as it allowed for a sail, which is pretty cool for a sub 8' dinghy. I bought the plans online and continued to scour youtube for hints while waiting for the plans to arrive. The plans soon took pride of place on the dining table while I considered my next move, and considered how to build plans given entirely in inches and sixteenths!

LADDER:
I started with the ladder as it was simple and would give me both an appreciation of the size required and a low 'saw horse ' to cut larger sheet material on. Using F7 pine 90x4mm, cut to the plans with a tape measure, square rule, pencil and a cordless Makita circular saw. Fixed together with leftover decking screws , and a cordless driver.

MATERIALS:
 Next was a trip to the local marine shops to look at plywood, epoxy, fittings, sails, oars and other exciting stuff! I bought the 1 litre of epoxy and a half litre of hardner with a set of pumps to allow for accurate metering of the glue into a plastic takeaway food container. 

Cheap brushes from Mitre10 were bought for use with the epoxy. I was surprised to find suitable marine grade plywood (8' in length, 2400mm) at Bunnings, and brought the 2 sheets of 6mm, 1 sheet of 9mm and one sheet of 19mm plywood back strapped to the roof rack. Soon that was safely inside the shed, leaning against the wall as flat as I could make it.

BOW AND STERN:
 To mark out the plywood for cutting, a great hint is to place the full size paper plans on top of a piece of 19mm ply and push in pins along the curves and at the joints. These pinholes are easy to join with a pencil, and preserves the plans. After cutting the pieces with a jigsaw, I measured and marked the extent of the bevels. 

Placing the cut ply on the 'ladder', I adjusted the bevel angle on the cordless circular saw, and cut by hand and eye! This was nerve wracking first time but actually quit easy due to the low weight and power in the saw. This gave me the bevelled stern, and bevelled bow, of the dinghy.

WHAT KIND OF WOOD FOR LAMINATIONS?:
I selected a short length of silver ash (1'x1" rough sawn) from Anagote Timbers at Marrickville to make the first laminated piece, the fore keel. 


LAMINATED FORE KEEL:

The mound was measured up on 19mm plywood, pushing the pins through the plan, and joining the dots as before. The mould was cut with a jigsaw. To hold the clamps, I used a wide spadebit on a cordless drill to cut holes 1/2" from the front of the mould. That allowed my clamps (small Record G-clamps) to be used along the curve of the mould.

To cut the laminations, I fitted a thin new 8" circular saw blade and played with the fence settings on my Triton workbench until I could rip a 3-3.5 mm lathe off the silver ash. I cut 15 lathes very successfully. I bent first three, then all 15 dry lathes around the mould to check the clamps and look for problems with the wood or my method. 

Next was to line the mould, and my work table with good quality waxed paper (the epoxy will leak straight through the cheap paper), mixed the epoxy, brushed both sides of the lathes and assembled on the mould. Used the Record clamps to pull the laminations tight, used a wooden mallet to gently 'persuade' the laminations to sit square, then poured/brushed more epoxy in for good measure. Pulled off after two days to see that uneven clamping pressure had warped the final result. Used a belt sander to take off the surface epoxy which is quite sharp! Will try to cut it straight on the table saw.

LAMINATED CENTRE RIB:

Making the laminated rib was similar but more care taken. I bought an 8' by 1' by 1" plank of silver ash. With assistance from my youngest, ripping and handling the 8' lathes was quite easy. The lathes are quite springy and easy to bend, and a dry fit trial, bending around two 90* corners on the jig did not break any. So I can thoroughly reccomend the Silver Ash - it is a great timber.

 Again with epoxy the laminations are quite slippery and the clamps could not pull around. So I pulled one end by one hand and used the large Record clamps to hold it. Using the smaller clamps to pull the bundle tight against the jig, working from the centre out to the ends. Again before tightening clamps fully, I sloshed in more epoxy with a brush. Left dry for two days. Not much movement when removed from the mould,and again sanded all over with a Makita belt sander. The finished piece looked great, smelled great, and the boys were really surprised how light and strong the finished piece was!

It's been a trouble to work out how to cut the centre laminated rib to the plan - a number of straight cuts that have to be cut accurately on a large and unwieldy shape! I tried to find simple solutions for hours, but eventually just clamped it between two sheets of plywood, using the top piece as an edge for the baseplate of the jigsaw to run along.  Of course, I cut it too close,  right on the line (duh!) and after sanding flat the laminated rib is now a little too thin - but I don't think it will sink the boat!

After cutting and sanding, I used the jigsaw to make a number of small cuts for the 'limbers' - I'm hoping these are not critical because my accuracy was a bit off - I'm assuming this is just to let the water run along the floor of the boat.

PLYWOOD BOTTOM AND SIDES:
 I was going to cut and shape all the smaller pieces of wood next and leave the eventual assembly of the hull until last, but I found that many pieces have few measurements and will have to be trimmed to, and fit against, the final hull assembly. 

 I looked at the side plank drawings with some trepidation as I had already made some mistakes dealing with the imperial measurements. It is most definitely "measure twice, cut once"!! However, it really turned out to be much simpler than I expected, and I soon had a series of plotted points. 

This time I drove small 30mm nails into the plotted points and bent a spare lathe of silver ash against the nails. Errant points, and there were 2 or 3, showed clearly and were quickly re measured ! Running a pencil along the lathe produced very pleasing curves for the three planks on the plan.

Placing the wooden 'ladder' on the lawn, and then two sheets of 6mm plywood on top allowed me to drill a 4mm hole on each empty corner, screw in a 4mm bolt and lock the two 6mm ply pieces together. Then I run a jigsaw along the pencil lines to produce both left and right sides of the dinghy (the garboard plank, centre plank, and sheer plank). The cut pieces were carefully stacked flat on shelving to prevent warping.

Cutting temporary bulkheads:
these were marked out with pins and the pin holes joined with pencil lines as the other moulds, using 3/4" plywood left over from making the bow and stern transoms.

ASSEMBLY:
finally got to start putting it all together - a little worried that the string line isn't dead centre down each of the moulds, but we'll see what affect that has on pulling the plywood sides down to the moulds later. (found out later it was quite important - resulted in rework!!)

From left to right, the bow and forekeel, stage 1 temporary mould, stage 2 laminated centre rib, stage 3 temporary mould, and stern transom.