Monday, December 12, 2011

Answers to a few comments

I apologise for not having replied to the last few comments, but I've been snowed under with other duties and this is my first opportunity: -

Rossco, Did Ross Trinder use 4mm or 6mm ply on his longer Water Rat? With my 9' Water Rat I used 4mm with a full length centre stiffener of 1/4" x 4" western red cedar ( from an old verical blind) plus some smaller ply pieces and a pair of heel pegs, between the centre stiffener & the chine.You can see these in the photos I put up in Duckworks Magazine forum under "Water Rat".The bottom seems quite stiff enough with these, plus of course,the fore & aft facing seat mounting cleats. My Water Rat weighs only 17kg,which is very light,so using 6mm will probably increase it to about 25kg which is still very portable. Would "rowerwet" be better advised to use 6mm if he intends surfing his boat? Al Burke
Ross Trinder used 6mm ply on his long version of Water Rat and she turned out to be about 28kg (62lbs) which is quite heavy. However, he said that he used locally-sourced "Pink" BS1088 ply. In Australia "pink" ply normally means Pacific Maple (Meranti) or a Malaysian hardwood like Keruing all of which are quite heavy. If built from 6mm Gaboon (Ochume) the plywood weight of all of the panels in a 10.8 ft Water Rat should weigh 10.5 kg (23 lbs). I'll leave it up to your judgement to work out how much the timber, glass, and epoxy would weigh.
As Al Burke points out, the boat can be made from 4mm material, but stiffeners will be required in strategic locations. The stiffness of a panel increases (and decreases by the cube of the thickness, so 6mm ply which is supported around all edges is 3.375 times the stiffness of the same panel in 6mm!
 Here is another one from my mate, Al: -

Rossco, By way of a general comment on both First Mate & Phoenix3,I have been impressed with the speed Paul Hernes achieves in the videos of him sailing in a stiff breeze & the ease with which he handles the boat.I know the sensation of speed appears greater when close to the water,but he is ceratainly clipping along. My question is:- are both designs able to break out & plane? Al Burke
Yes, Phoenix III can break out and plane. In the following photos you can see John Shrapnel sailing Paul Hernes' boat on a good day with a deep reef tied in the mainsail. This is a good demonstration that traditional rigs can drive a boat fast! I haven't had direct experience with First Mate yet, but I'd expect her to be as good or better due to being wider at the rail and easier to hold down. Both boats have substantial rocker, so they sit bow-high when planing, but the result is not extreme.

From Shaun come two nice comments: -

Your photos and step by step explanations are a huge selling point for me. They keep bringing me back to the blog. Not only are you highlighting your designs but are show casing the workmanship that goes into turning out a beautiful boat. I am hoping to make my first build a Flint with sails. I started a bit backward and have built some spoon oars first to get the hang of epoxy. Cheers, Shaun
Nicely done photos and commentary, makes me believe I could replicate the process. I am interested in trying some bird's mouth oars. Do you include such plans with your Flint design? Cheers, Shaun

Shaun has said that he has started backwards by building oars first, in order to gain experience with epoxy. I think this is an excellent approach for an inexperienced builder and I encourage the method. The other thing to do is to build a very small tender of simple canoe so as to get the hang of the processes. In my First Mate plans I include patterns for a simple galley box which is made as a mini-stitch-and-glue project.

No, Shaun, there are no Bird's Mouth spar plans for Flint, as the spars are so short and slender that the weigh saving does not justify the trouble. In fact, the spars for Flint are parallel-sided and can easily be made out of a wide variety of materials including alloy tube and carbonfibre tube. I'd make them from timber - it feels nicer to the touch.

I'm currently finishing off the Whimbrel plans, but due to workload the process will take about another month, I think. I like the boat very much indeed, and she should be a simple project for someone who has some experience.

1 comment:

  1. Ross - quick question on whimbrel. Is she to be a pram/scow bow craft? If not, could the plans be fairly easily amended for a pram bow option? A pram bow, coupled with the leeboards would sure make a roomy little craft for the overall length.