Wednesday, December 23, 2009

Aquatic Park Row boats

Last Sunday, I went with Allison and Louise to Aquatic park and visited the Dolphin Club

 

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Dolphin Club
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South End Rowing Club
 


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Allison and a Wherry

 
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boat155 NaturesValleyMay2009147
Restoration of a 9 Person club boat
 


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Louise
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8 Person “John Wieland” boat from 1887
 
miscSF167Allison and her painting of swimmers from below.

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Nearby Dolphin Club art show,
Joe, a member and club photographer.
 

Sunday, December 20, 2009

Lining Off – Alex’s 12’ sailboat

Last Saturday class we learnt about Lining Off.  We discussed how to approach the Freda and it’s difficult shape.  A plank width vs station is created full size for the width, but scaled down on the section spacings, drawn on a small piece of wood ( 9” x 36” ) board.  A batton is laid down on the width ( derived from space/#planks ) coordinates and a faire curve is sort out.  The posibbly revised widths are harvested and the next few weeks of planking work can be known.

Here is Bob braving the cold and demonstrating this:

 

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On a smaller boat, like Alex’s lovely 12 foot wooden sailboat.  It’s taking shape in his garage, and it just fits!  A straight edge is first  lain down, more or less on the diagonals.  Basically two elements are discovered with this process.  The shape and width of ones planks, important for lumber ordering as well as knowing if there are any reasons for scarf joints ( an 8 inch plank can be made to frown or smile ( exaggerated ) rather than one long 14 inch board ).   Furthermore, it also helps one to understand just how difficult it may be to build the boat.  Alex’s midsection is a beautiful wine glass S-curve, so it soon became clear that this was going to be hard to build, as it will be difficult to get the planks to bend around the moulds.  Additionally one learns plank widths and layout ahead of time, helping to plan a pleasing planking schedule and resultant aesthetically pleasing boat.

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Tuesday, December 01, 2009

Jewler’s Burnishers for finishing scraper blades …

http://www.deltaonelapidary.com/detail.php?id=2794

Safety and comfort

Key elements to existing in or on water in boats.

Safety, think no air or too cold = drowning or hypothermia

Comfort, think no sea-sickness and a peaceful nights sleep.

So many boats are so fast and jump all over the place, so at the end of a trip you arrive exhausted and agitated, not great if your destination is the Marquesas and you wish to enjoy the beaches etc …

“fiberglass resin will make your liver quiver”

Yes, not a great option for longevity, what are the alternatives, i’m particularly interested in filling up ‘knot’ holes in wood, I like the idea of a clear filler rather than opaque wood fillers/putty.  Once I find suitable alternatives, I’ll post it here …

http://sculpture.net/community/ has some interesting posts

bio-resin : http://www.canonburyarts.co.uk/bioresin.html

jesmonite: http://www.canonburyarts.co.uk/jesmix.html

hmm will have to check these out …

Sunday, November 29, 2009

Scraper or Sandpaper?

I grew up with the notion that sandpaper was the way to finish a wooden project, and later learned that steel wool was also the way to go.

SCRAPERphoto

So there is a better alternative to the dust and fine particles from sanding.

The “cabinet scraper”, correctly sharpened can produce a better finish than even some Japanese finshing plane, especially in highly figured or gnarly and knotted woods.  The blade requires some special attention – firstly the width of the blade’s diagonal edge, needs to be approximately 1.5 to 1.7 x the thickness of the blade.  Knowing this, the angle is evident.

The blade is a Hoc scraper blade, which cost about $45 and really makes a difference.  The blade is 2” wide and best sharpened this way.

Firstly hold the blade on the edge of a table top, and use a bastard file to get the initial edge.  Do not use a wheel grinder, the bastard is a good tool to get a flat edge.  Once a nice bur is obtained move to the diamond stone.  Progress to bester, then to polishing stone, all the time paying attention to a flat back and a good flat forward angle.

The final part is to properly use a Jewler’s Burninshing rod tool with some 3in1 oil work the sharp edge into a curl of steel – this is the very secret to the tool taking off fine shavings regardless of grain direction.  Even the Japanese can’t do this.

So given that there are no sanding partilces only shavings and no noise and expensive sandpaper, give me a scraper any day!

Thursday, November 19, 2009

Bronze Casting – Sand Method

Last weekend we witnessed an actual bronze casting.  Bob Darr our teacher at the Arques Wooden Boat School set up the air blast propane forge.  Simply put it is the bottom third of a 55 gallon drum that is partially filled with a special cement, an inch and a half pipe is set at an angle and functions as the fuel input into the forge.

 

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For the bronze stock, Bob tried out an old propeller shaft, which Alex cut up into small three inch pieces.  When heated, to approximately 1800 – 2000 degrees Fahrenheit

Bronze Casting

The bronze melted in about 45 minutes, and by using a modified carpenters square, the ash and impurites are skimmed off the surface.  The alloy was also seen to be burned off, as seen by a green glow to the top of the forge. 

Bronze Casting

Two people then hold the crucible and pour the liquid bronze into the forms.

Bronze Casting

Flasks are only opened the next day, to ensure that the minimum amount of the expensive petrobond sand is not burned.  Here is Alex’s bronze dolly ( used for riveting and clinching boat nails and roves )

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Unfortunately the last flask was not a great success, as the bronze was cooling down by the forth pour ( each pore was about 2 minutes ), here one can see the bronze cooled before it reached the extent of the cavity in the form.

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Bronze Casting

Here is Alex’s finished dolly.  He opted not to patina it, but michael did, using phamarcy bought peroxide and wine vinegar heated with a blowtorch.

Here is some other items Bob wanted, a mast step’s support and a bow post cap.

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( Added later a link to a ‘safer’ version of Petrobond is something called K-Bond )

Tuesday, March 10, 2009

Bronze casting video

We've not done this yet at Arques, but this video from Rauscher boatworks seems quite informative http://www.youtube.com/watch?v=jFOo5EWNl8M

Friday, February 06, 2009

Bainskloof longdistance swimmer ‘Hull’ study

Carina Bruwer and I headed out to Bainskloof rivier and the river water was very nice indeed

k42 k51 Carina regularly swims distances over 30km. I was honored to join her attempt to break Robben Island crossing, she missed it by 3 minutes, 10km in 3 hours and 45 minutes.

Monday, January 19, 2009

Finished sawn frame at Station 17

archived

Knots

Knots learned with Bob Darr:

Bowline ( with eyes closed and one hand )
Clove Hitch
Rolling Hitch
Sheet Bend
Whipping and Serving
Eyehook splice

Monday, January 12, 2009

Milling Black Locust in Nicasio Valley







This Saturday we went on a field trip to learn and observe how to 'Mill your own Wood' with relatively simple and inexpensive equipment.


The idea was to drop the tree with a chainsaw and guide it's fall into the creek bed where we would do the milling. Bob cut an 18 foot 'Black Locust' tree which fell perfectly into the creek.



Oscar weilds the Peavey
The log is rolled into optimal cutting position with a neat looking tool called a "Peavey".






Bob flattens the top of the fallen tree with an Adze - so that the plank can be nailed to it. Wooden wedges are used to stabilize the plank so that the mill can operate smoothly. Plank was slightly cupped, so that side is placed upwards.





Julie mills - by pulling on a simple handle with two long cords attached to the chainsaw mill. The rpm are supposed to be high in order to preserve the engine and prevent a stall in the middle of a cut, one pushes in with a choke style throttle.






At the end of the day we had cut two 9' x 3.5" x 12" black locust board, with a slight curve in them, they were priceless, and even if the yard had curves it would have been a few hundred dollars worth.

The mill is basically a modified large chainsaw engine, attached to a custom chainsaw blade, which is framed and has rollers to allow the equipment to smoothly roll over the plank, while sawing. This could be achieved by holding the mill direclty and with a helper on the other end, but that would be too dangerous, as the chain could break. By pulling with the ropes you are ten feet away, so it is relatively safe to use.

Great outing and will definately add a mill to list of things I want for Christmas.






Bod Darr Wooden boat magazine 1980 I found the pdf of this article from thiry years ago - the equipment is the same, however the engines do burn out, he's replaced the engine every ten years - Nice Stihl engines 090AV. The mill is called an alaskan mill and more info about the mill is availible here

Tuesday, January 06, 2009

Half model of a Hershoff boat


Heeling increased the effective sailing length from 46’ to nearly 70’

The ‘Defender’

 

The yacht that made Herreshoff, Captain Nat famous, the Gloriana 1891.

I bought a the plans and lines to create this half model of Gloriana


Sloop designed by N.G. Herreshoff in 1891. A revolutionary yacht, she featured a convex bow rather than the then-current long, hollow entrance. Overall length of the finished model is 36''.
4 pages of plans historical information about the boat and step-by-step instructions for half-hull building,using the lift method.
There are also detailed drawings, including full-sized patterns for each lift, as well as template for you to shape the profile.

Calculating Camber

archived