Jaager

There are lines that belay at the base of a mast.  There are bitts and sometimes pins or cleats on a mast.  Rather than set up a situation wear a line would constantly rub by going inside the floor of a top and then on to the side, I would expect it would be more efficient to go outside the floor to the side of a ship. 

It is my thought that double layer planking is used when the number of moulds is too few to allow a single layer of planking of any thickness to support a proper run without hollows.

Boats are relatively small.  They are uncomplicated.  A kit that uses short cut techniques and an inadequate mould structure is a red flag and indicates  a  poor quality kit.
Scratch building a boat for a kit model used to be a gateway and introduction to making the jump to scratch building. 
 

I am rather surprised to read about double-planking for a kit of an open boat. The rough first layer of planking would be very visible on the inside, doesn't make much sense.

Back in the day, Ship model kits were centered on machine carved solid wooden hulls; a technology invented over 100 years earlier to mass produce wooden gun stocks.  The model maker finish carved the hull, and added stempost, sternpost, keel, etc. In the hands of a skilled modelmaker excellent and accurate models could be produced from these kits.
 
In the 1970’s-1980’s these kits began to be displaced by European Plank on Bulkhead kits that claimed to allow models “to be built like the real ship,” even though with their widely spaced bulkheads  they had more in common with model aircraft.  Comparing the two types of kits, it’s easy to see why European kit manufacturers favored their system.  It cost them much less to provide and ship strip and sheet stock than large blocks of quality wood.  It is also possible that novice model makers found this form of construction less intimidating than finish carving a solid hull, until they began planking, but by that time they had already spent their money.
 
But now the kit manufacturers had another problem.  Bending strips of wood around a few widely spaced bulkheads would not necessarily provide a fair (smooth) hull, let alone one that faithfully represented the actual ship.  To overcome this problem, they adopted the Double Planking System.  By using this system, the builder has an opportunity to fair his hull before adding the second planking layer.  Just like the real thing?  Hardly!
 
If for some reason I was to build one of these kits, I’d add solid blocks between the bulkheads and properly fair the hull.  Then  I’d plank the hull with a single layer of quality planking.  But if I were going to go to this effort, I’d just rather build a model from scratch.
 
Roger
 
 

It is my thought that double layer planking is used when the number of moulds is too few to allow a single layer of planking of any thickness to support a proper run without hollows.

It is my thought that double layer planking is used when the number of moulds is too few to allow a single layer of planking of any thickness to support a proper run without hollows.

It is sodium bisulfate  (bisulphate).
Here is a quick link that I found : https://mistralni.co.uk/products/sodium-bisulphate-sodium-hydrogen-sulphate
 
It is seriously acidic, but not so potentially violent as sulfuric acid.   Concentrated sulfuric acid "wants" to combine with water.  Much energy must be used during manufacture to concentrate it.   When it recombines with water, it gives back that energy instantly,  If there is more acid than water, the heat is high enough to flash the water into steam.  Adding water to acid, this will produce a steam explosion and acid will be ejected into the air.  The effect of the acid in skin is not unlike holding a live steam nozzle right on your skin.  It will get your attention.
 
If I read it correctly, given times and exposure to oxygen, a sodium bisulfate solution will become a sulfuric acid solution. 

It is sodium bisulfate  (bisulphate).
Here is a quick link that I found : https://mistralni.co.uk/products/sodium-bisulphate-sodium-hydrogen-sulphate
 
It is seriously acidic, but not so potentially violent as sulfuric acid.   Concentrated sulfuric acid "wants" to combine with water.  Much energy must be used during manufacture to concentrate it.   When it recombines with water, it gives back that energy instantly,  If there is more acid than water, the heat is high enough to flash the water into steam.  Adding water to acid, this will produce a steam explosion and acid will be ejected into the air.  The effect of the acid in skin is not unlike holding a live steam nozzle right on your skin.  It will get your attention.
 
If I read it correctly, given times and exposure to oxygen, a sodium bisulfate solution will become a sulfuric acid solution. 

I think some of the disappointment in the instructions of most traditional wooden ship model kits lies in their different evolutionary pathway from plastic kits.
I think plastic - being a new material - post WWII - and the subjects for the kits were metallic and heavily engineered with lots of detailed plans for the original ships or aircraft or rail or war machines.  The plans for each kit were complete and self sufficient.  Plastic kits are mostly about assembly of pre- formed  components. Plus- now very sophisticated finishing techniques.  In origin, it was just a few jars of Testors oil based paint and a basic small brush.
 
Wooden ships - pre 1860 - had a different sort of plan.  The construction the shipwrights art and was pretty much common to all vessels - with changes from generation to generation.  So there were no voluminous detailed plans to copy for a kit.   
The original versions were solid carved hull scratch builds, using instructions in magazines like Popular Mechanics.  I see the kits starting as a shortcut for those not wishing to carve a block of Pine or Basswood.  
There were a few  how-to  books that were expected to be the major source for directions.   The kits just provided some materials for what was still essentially a scratch build process.  Kits became more involved and reduced a lot of the scratch build aspect.  It was still assumed  that general instruction books would be used for learning the basic techniques.   For wooden kits, it is about first shaping the components and then assembling them.   The basic skills are mostly the same for all kits, so detailed instruction for any single kit is just repeating the same instructions over and over.  It also involves a multitude of tools, that must be learned and practiced with.  
 
 
 

I agree! You just assemble a plastic kit. "Glue part number 5A into hole number 5B" and so on. There's no need to understand what the part is called or what its function might be. To a greater extent, particularly with earlier wooden models, be they ship or otherwise, at least before laser cutting, is was just assumed by the manufacturers that their customers has some basic understanding of what they were building and adequate woodworking skills to cut and fit the parts together.  Unfortunately, many of recent generations are often clueless when it comes to the manual arts and the high schools by and large abandoning their shop classes hasn't helped any, either. Anybody starting in out in sailing ship modeling would do well to start by reading Chapelle's Boatbuilding and learning how a wooden boat is built from the lines up. That will make their modeling tasks much more understandable. Of course, such advice would be sure to fall on deaf ears in this age of instant gratification. How many kids today know "righty-tighty, lefty-loosey?"
 

I think some of the disappointment in the instructions of most traditional wooden ship model kits lies in their different evolutionary pathway from plastic kits.
I think plastic - being a new material - post WWII - and the subjects for the kits were metallic and heavily engineered with lots of detailed plans for the original ships or aircraft or rail or war machines.  The plans for each kit were complete and self sufficient.  Plastic kits are mostly about assembly of pre- formed  components. Plus- now very sophisticated finishing techniques.  In origin, it was just a few jars of Testors oil based paint and a basic small brush.
 
Wooden ships - pre 1860 - had a different sort of plan.  The construction the shipwrights art and was pretty much common to all vessels - with changes from generation to generation.  So there were no voluminous detailed plans to copy for a kit.   
The original versions were solid carved hull scratch builds, using instructions in magazines like Popular Mechanics.  I see the kits starting as a shortcut for those not wishing to carve a block of Pine or Basswood.  
There were a few  how-to  books that were expected to be the major source for directions.   The kits just provided some materials for what was still essentially a scratch build process.  Kits became more involved and reduced a lot of the scratch build aspect.  It was still assumed  that general instruction books would be used for learning the basic techniques.   For wooden kits, it is about first shaping the components and then assembling them.   The basic skills are mostly the same for all kits, so detailed instruction for any single kit is just repeating the same instructions over and over.  It also involves a multitude of tools, that must be learned and practiced with.  
 
 
 

I think some of the disappointment in the instructions of most traditional wooden ship model kits lies in their different evolutionary pathway from plastic kits.
I think plastic - being a new material - post WWII - and the subjects for the kits were metallic and heavily engineered with lots of detailed plans for the original ships or aircraft or rail or war machines.  The plans for each kit were complete and self sufficient.  Plastic kits are mostly about assembly of pre- formed  components. Plus- now very sophisticated finishing techniques.  In origin, it was just a few jars of Testors oil based paint and a basic small brush.
 
Wooden ships - pre 1860 - had a different sort of plan.  The construction the shipwrights art and was pretty much common to all vessels - with changes from generation to generation.  So there were no voluminous detailed plans to copy for a kit.   
The original versions were solid carved hull scratch builds, using instructions in magazines like Popular Mechanics.  I see the kits starting as a shortcut for those not wishing to carve a block of Pine or Basswood.  
There were a few  how-to  books that were expected to be the major source for directions.   The kits just provided some materials for what was still essentially a scratch build process.  Kits became more involved and reduced a lot of the scratch build aspect.  It was still assumed  that general instruction books would be used for learning the basic techniques.   For wooden kits, it is about first shaping the components and then assembling them.   The basic skills are mostly the same for all kits, so detailed instruction for any single kit is just repeating the same instructions over and over.  It also involves a multitude of tools, that must be learned and practiced with.  
 
 
 

I have no idea what the species in your photo is, but it looks like a poor choice for planking a ship model.  If you can remove the already applied planking of this stuff,  you should consider substituting the planking with a more appropriate species. 
Already milled planking in the same color range from Modeler's Sawmill would be Castelo or AYC.   If you can do you own milling, there are more choices.  Hard Maple, Beech, Birch,  or even Yellow Poplar if you choose carefully for the light color cuts - probably about 25% yield.  

If you are framing at a scale larger than 1:96, any of the species that go under the name Boxwood would be an indulgence.  They would do the job, but other more available and less expensive would do just as well.  The loss to waste in framing is significant.
Beech is very close to Hard Maple in color and density.  The variation in possible grain pattern is (I suspect) much less with Beech.  In Europe, I suspect that Beech is less expensive and much more available than it is in North America.  There, for a light color framing timber, the cost and availability options are probably Beech or Sycamore maple, European sycamore (Acer pseudoplatanus).
In North America, the price advantage goes to Hard Maple (Acer saccharum),  Beech seems to be a premium price import.  There are other domestic species of Maple commercially available, but most are close to awful when compared to Hard Maple in density and friability.   If domestic Beech is locally available and the price is right, it may be worth using, with the caveat that Fagus grandifolia is less dense and similar to Black Cherry in this.
For components, other than framing timber, The reduced loss to waste evens the field and makes availability the main factor.
For commercial species that are darker, in North America,  Black Cherry is much less expensive and easier to obtain than European Pear.  Pear is by far the superior as far as density and uniformity of grain.  If you can get and mill it, ornamental Pear (Pyrus calleryana var,) wins against either.
 

If you are framing at a scale larger than 1:96, any of the species that go under the name Boxwood would be an indulgence.  They would do the job, but other more available and less expensive would do just as well.  The loss to waste in framing is significant.
Beech is very close to Hard Maple in color and density.  The variation in possible grain pattern is (I suspect) much less with Beech.  In Europe, I suspect that Beech is less expensive and much more available than it is in North America.  There, for a light color framing timber, the cost and availability options are probably Beech or Sycamore maple, European sycamore (Acer pseudoplatanus).
In North America, the price advantage goes to Hard Maple (Acer saccharum),  Beech seems to be a premium price import.  There are other domestic species of Maple commercially available, but most are close to awful when compared to Hard Maple in density and friability.   If domestic Beech is locally available and the price is right, it may be worth using, with the caveat that Fagus grandifolia is less dense and similar to Black Cherry in this.
For components, other than framing timber, The reduced loss to waste evens the field and makes availability the main factor.
For commercial species that are darker, in North America,  Black Cherry is much less expensive and easier to obtain than European Pear.  Pear is by far the superior as far as density and uniformity of grain.  If you can get and mill it, ornamental Pear (Pyrus calleryana var,) wins against either.
 

The main factor is  the degree of accuracy in shape.  More stations = greater accuracy

The main factor is  the degree of accuracy in shape.  More stations = greater accuracy

Tracing the kit, I find: Blue Jacket  
The description lists the paint colors supplied.  One of the colors matches True North model paints.
The kit supplies a thinner.  - Were it acrylic - water based, no thinner would need to be supplied - water is commonly obtained.
True North says their product is alkyd.   This is oil based.  I have always had a mental conflict with the term 'enamel paint'.
I have tools and pots that are enamel coated.  Whatever is used to make that coating does not seem to match what a model enamel paint does.
What is seems to mean is that the pigment is suspended in linseed oil ( or similar plant based oil) and an organic solvent.
Reducing the concentration of the linseed oil should reduce the viscosity and allow for a thinner layer more easily spread.  It also reduces the concentration of the pigment, so more layers will be needed o get a desired final density.
 
Use the supplied thinner.  Alkyd lists both alcohol and organic solvents as possible thinners.  The alcohol is probably 95% ethanol (denatured alcohol) ,  the organic could be mineral spirits,  but turpentine works at least as well  or naphtha.  Turp smells better.

Tracing the kit, I find: Blue Jacket  
The description lists the paint colors supplied.  One of the colors matches True North model paints.
The kit supplies a thinner.  - Were it acrylic - water based, no thinner would need to be supplied - water is commonly obtained.
True North says their product is alkyd.   This is oil based.  I have always had a mental conflict with the term 'enamel paint'.
I have tools and pots that are enamel coated.  Whatever is used to make that coating does not seem to match what a model enamel paint does.
What is seems to mean is that the pigment is suspended in linseed oil ( or similar plant based oil) and an organic solvent.
Reducing the concentration of the linseed oil should reduce the viscosity and allow for a thinner layer more easily spread.  It also reduces the concentration of the pigment, so more layers will be needed o get a desired final density.
 
Use the supplied thinner.  Alkyd lists both alcohol and organic solvents as possible thinners.  The alcohol is probably 95% ethanol (denatured alcohol) ,  the organic could be mineral spirits,  but turpentine works at least as well  or naphtha.  Turp smells better.

Back when wooden hulls were used as waterborne trucks and commercial cargo was involved, there was standardized insurance and insurance mandated scantlings.   After WWI, that blip was a panic driven aberration, perhaps,  wooden hulls seem to have gone individual customer and wild west as far as universal scantlings.  My guess anyway.   The addition of man made components such as plywood, metal framing(?) fiberglass,  Each vessel is probably its own world as far as looking up scantlings is concerned.
 
That said,  the physics of wood did not change after WWI.  You do not provide any basic data for this vessel, or I missed it.  So, from Meade 1869
Frame moulded dimensions for a vessel with a moulded breadth of 15 feet  (The next column is 20 feet.)
Floor timbers sided, at least                                                4.75"
Top timbers sided                                                               4"
Moulded at cutting down (outer edge of keel/keelson)     6 - 6.25"
"    at middle between keel and waterline                          4.5 - 5"
"   at LWL                                                                            3.25 - 3.75"
"   at main deck                                                                  3 - 3.25"
 
I use a raster based drawing program to loft  and use disks that are scale diameter of the moulded scantlings at each data point.  I have intermediate sizes of those diameters to shape a transition that  is strong where needed and has a curve that is pleasing to the eye.  A line that meets each of those circles at a tangent provides the inside moulded dimension.  Being a two finger typist, I took me longer to type this than actually develop a moulded curve when lofting.   I do all lofting at 1/4" : 1'  so I only had to make one set of disks and keep it in a base starter file.  I have a picture or two on my Renommee build.  
 
 

Ed,
 
Where is it being used?
If it is POB and filling cracks in a first layer of hull planking, my question is: Why bother? The outer layer of planking will cover the gaps anyway.
If it is to flesh out minor hollows in the planking run, then it should as well as it needs to.
If there are serious hollows, better it would be to use thin strips of wood, PVA bonded at the hollows and sand these scabs into a smooth run.
 
For places where a clear finished wood is on display,  wood flour of the same species mixed with white PVA usually does a fix that takes effort to notice.

Jeff,
 
The size of the chisel is determined by the job it is being used for.
Dockyard micro chisels are a size for decorative carvings - usually 17 century and first half of the 18th century.
For larger jobs there are FlesCut and UL Ramelson. 
FlexCut are not difficult to find.
Mountain Woodcarvers  sells both Dockyard and Ramelson.
This company is having a sale on factory seconds from Dockyard. 
 
UL Ramelson has a web site and individual chisels are available there.
 
It is a pain to wait and frustrating not to have what you need , when you need it.  The economical way would to get to a task, guess the size and shape of chisel needed and buy just those.  This advice that I cannot practice myself,

Plastic model assembly is not really all that much help in preparation for the skills and tools used for building a wooden hull.  
A major advantage of a wood based model for a plastic one is that it is much easier to backup and redo - often with much better quality wood - if you so choose.   The plans that come with the kit should have the patterns  for the parts that have been poorly assembled.  Obtain plywood stock,  It can be AA quality and thicker than the kit supplied.  Scan the patterns - double check for any scanner distortion and adjust and cement to the new plywood, cut the replacement parts out and assemble using your hard learned experience.    Check the vendors here,  planking stock is available.  The species will be much more scale appropriate. 

Willem van de Velde the elder has some work from before 1650.
 
The Galleon by Peter Kirsch may have a few illustrations that are after 1600.
 
There is a major spike in interest and available material  from 1588  and another from around 1660 on.  What was in between, and it was a period of major transition , seems to be lost to the fog of time.