Over the last few months I have been rowing my Acorn 15 regularly because I enjoy it and I need the exercise. My Acorn 15 rowing boat has a fixed rowing position and I decided that it would be a good idea to try rowing with a sliding seat to get a more complete workout. One option would have been to modify the Acorn 15 by fitting a sliding seat. I wasn't keen on doing this because I didn't want to spoil the look of the Acorn 15. It would also have been a compromise solution.

While these ideas were going round in my head I came across the photo below taken by my friend and fellow member of the Wooden Boat Association of Queensland Ian Primrose.

The photo is of a Classic Derwent Skiff designed by Allan Witt of a company called Row and Sail based in Tasmania.

I liked the appearance of this boat which is configured with a sliding seat as shown. The rowing position can be moved forward and an additional seat added for a passenger if desired.

This version of the Derwent Skiff is 5.5 metres (18 feet) long and should weigh around 38 kg. This is less than half the weight of my Acorn 15.




Monday 23 April 2018

First Coat of Varnish.

In the last post I had sealer on the inside of the hull. Since then I turned the boat over , sanded the outside of the hull and gave it two coats of the Wattyl sealer. Here is what the first coat of sealer with 50% thinners does to the plywood.


I had to wait a couple of days for the sealer to harden up enough to sand. in that time I sanded and sealed the rigger arms and the buoyancy tank. Final sanding this morning and then the first coat of varnish applied.  A couple of photos show the hull and the buoyancy tank and rigger arms.



At them moment it is all looking pretty good. There are blemishes but I'm not going to point them out and other people might not notice them!




Sunday 15 April 2018

Sealer On The Inside

With the cross supports fitted under the well decks the final cleaning up of the compartments was a fiddly job because power sanders couldn't be used effectively. Hand sanding did the job.


Here is the aft compartment looking much better with epoxy fillets reinforcing the inside corners.


The compartments were given 3 coats of Wattyl SeaPro TP80 sealer. This is a 2 part sealer witha relatively long pot life and it is quite easy to apply. The first coat was thinned with 50% Wattyl L760 thinners. The warnings on the labels say "good ventilation" and I needed it; for the first time ever the fumes from this stuff made me feel quite woozy. I opened the window and fetched a big pedestal fan!

The decks were glued in place after the sealer dried. Here is a photo of the hull ready for sealing. This is after a LOT of sanding and finishing work - shaping the inwales and adding the breasthook and quarter knees.


Two coats of sealer this time. Again the first coat was thinned 50% and the wood really soaks it up. I will need to buy another 2L kit of the sealer to do the outside of the hull.

Applying the sealer under the breasthook would have been difficult with a straight paintbrush so I modified one. It worked very well.



 Photo of the hull with the 2 coats of sealer. It looks quite good and I think it will look better when it is varnished.


Over the past few weeks I made contact with one of the school rowing clubs as I walked past their premises on the Brisbane River. At the end of the season (about now) the clubs check all their equipment and work out what needs to be replaced, repaired, etc. The result is a number of oars which have reached the end of their life as far as competitive rowing is concerned. The upshot of all this is that I now have two sets of oars, one 2880 long and the other 2850 long. They have carbon fibre shafts and are very light. The only downside to this is that my oars were used by a girls crew and have pink blades and handgrips - easily fixed!


I'm off for a few days R&R with the local wooden boat guys tomorrow and I reaaly feel the need for a rest after all the sanding!

Monday 9 April 2018

Turned Over

It was a relief when I was able to lift both ends of the hull off the mold. All that packing tape and pieces of plastic sheet had done their job. First step was to hoist the boat up in the air so the mold could be pulled out from under it and disassembled. If anyone reading this wants to build a Classic Derwent Skiff the mold is for sale.

 Next step was to lower the boat a bit and rearrange the slings so that it could be turned over. It isn't heavy so this was easily done. With it the right way up the hull was lowered further to sit in the three cradles on saw horses.

The inside of the hull looked very messy with a lot of squeezed out epoxy along the plank laps. a few hours work with a hot air gun and scraper cleaned it up. Here are a couple of before photos.






There are fore and aft buoyancy compartments, basically a bulkhead with a deck on top. The bulkhead is 4mm ply with doublers at the sides and a strip of 12mm square timber across the top. They are trimmed  to fit and then glued in place. Here is the aft one with paver clamps and two horizontal supports to stop it falling over.

The edges of the deck fit on the edge of the middles plank which, due to the angle of the planks is very narrow so two 10mm square strips were added to provide a better gluing surface.


Some cross supports are needed and these can be sen below. Cutting these to length and shaping the ends to fit around the 10mm square stuff was difficult - thank goodness for the gap filling properties of thickened epoxy!

The same was done for the forward compartment.


There are two inwales about 1250mm long. These provide two supporting points for the outrigger arms as well as adding some stiffness to the centre of the boat. The inwales are laminated in the boat from 3 pieces of Western Red Cedar. Here the laminations are being glued over plastic strips and newspare to catch any drips.

The inwales are then clamped in place and the top edge planed down to an angle to match the underside of the outrigger arm. This is a process of plane a bit off and see how it fits until the whole length id done. The underside of the inwale is then planed on the bench; a tricky job because it is hard to hold and banana shaped. Once it is done the ends are tapered and the inwale glued into the boat.


Wednesday 4 April 2018

Almost Ready to Turn Her Over

It has been a week since the last post, quite a lot of time spent int he boat shed and my shoulders ache from hand planing! There doesn't seem to be a way to avoid it. I'm a great fan of power planes but in some places the risk of damage is too great.

The start of the planing was bringing the edges of the garboard planks down flush with the top of the keel. It was awkward reaching up and out to the middle of the boat to do this planing so I climbed up onto the hull to get a better approach. Once done I could prepare a 5 meter long length of 100 x 6 mm hoop pine to cover the edges of the garboard plank. This had a scarf joint in the middle and once ready it was glued down using about 40 200 mm square pavers to hold it down. Once the glue set I climbed back up onto the boat to plane the edges of this keel trim flush with the garboard plank. Unfortunately I didn't take any phots while I was doing this.

The cutwater is made up of 6 x 4 mm thick laminations of hoop pine. Clamping them onto the stem was a tricky exercise involving clamps, threaded rod and a prop from the garage door. I did a trial run of this at the end of the day intending to leave it overnight to encourage the laminations into their new shape. Unfortunately I forgot the prop which was bearing up onto tilting door of the shed and when I closed the door there was a loud bang and stuff flew everywhere. Fortunately no damage done but I set up a notice to remind myself not to do it again when the glue was going off!


While the cutwater was being glued I set up the outrigger arms and the buoyancy tank for gluing. The arms are bolted down to a flat surface using bolts 1600 mm apart. The buoyancy tank is propped up on four legs behind the arms. Two plywood gussets have to glued to the arms, each gusset has 3 holes which have to line up exactly with the 3 holes in the end of the tank. One bolt passes through the gap between the inside ends of the arms (at the top). The other two bolts pass over the arms and just touch them. Glue is applied to the arms and gussets, the 3 bolts tightened into captive nuts inside the tank and an additional clamp used  for good measure. Because the bolts were very close to glued surfaces I smeared them with wax to prevent the epoxy getting hold of them.


The next photo shows the skeg being glued into place using props from the shed roof. This was straight forward but shaping the skeg which tapers from 25 mm thick at the keel down to 19 mm thick at the top edge involved more hand planing.


The gunwales are made up of two laminations; the inner one is Western Red Cedar, light and easy to work. The outer lamination is hoop pine, heavier but tougher to take the knocks. The next two photos show the outer lamination being glued in place. There are a mixture of clamps being used and also so brads through scraps of plywood to stop the joint squirming about.



Before the gunwales could be glued on the cutwater had to be faired to suit the angle of the planks. Because the garboard plank twists as it comes to the stem the angles are constantly changing. This was the main cause of the aching shoulders! It is hard planing on a near vertical surface and a lot of the work had to be done with a rebate plane because of the changing angles. Eventually it was done!

I will do a bit more cleaning up of the outside of the boat and then turn it over. I wonder what the inside of the hull will look like? There will be squeezed out epoxy to clean up but I hope the joints will be tidy enough for me to varnish the inside of the boat.















Gone to a New Home.

 Sadly I have parted with my Derwent Skiff. I loved the feeling of flying over the water that came with the long oars and sliding seat but t...