Bob Cleek

You have to consider the "scale viewing distance." How far back from the full-size vessel would you have to stand to see the entire vessel from stem to stern. Measure something the length of the vessel and get the number from that. Then do your "full-size" test panels as you have and stand as far away from them as you would have to stand off from the full-sized model to see it all at one time within your field of vision. Reproduce what your full-size test panels look like at the "scale viewing distance" above on your model's hull. Don't expect to see anything near the detail you've got at full-size viewing distance up close.
 
I doubt copper plates were ever fastened with iron nails. If they ever were, you can bet it wasn't for long for the reasons stated. Copper plates were fastened with copper "tacks," much like copper flashing on a roofing job. The iron electrolysis problems with coppered bottoms involved the iron fastenings of the ship's hull timbers themselves. Signs of rust wouldn't generally be a major visual feature of a coppered bottom. 
 
Weed growth was little deterred by copper sheathing, although continual sailing scoured the bottom pretty well. Weed growth was (is) most pronounced around the waterline where the sunlight penetrates. Weed growth diminishes as the turn of the bilge is reached and the hull surface is shaded by the hull above. When a vessel is hauled, this weed and algae growth is immediately removed by hosing or scraping, which is easily accomplished. Once it dries, it is much more difficult to remove. In tropical waters, bottom fouling could quickly become excessive, particularly if the vessel was not actively sailing for any period of time. Ships were generally careened whenever possible, even if just upon shore, in order to maintain a much faster and maneuverable vessel. 

Correct you are. These can be had used for very reasonable prices, or even new. Buy the best you can afford. (Read the ratings online.) Good used ones are remarkably affordable. The Wen 16 inch Speed Scroll Saw gets high marks at the low end of the price spectrum at $120 on Amazon. If you can afford to pay more, for which you will get more, look at brands such as the higher-end  DeWalt 20 inch Scroll Saw, the Excalibur 16" Scroll Saw, anything from Hegner, if you can afford it, and anything from Sakura if you can find it. (Supply chain issues have apparently limited availability of these high-end Japanese imports for the moment.)
 
There are two basic types of scroll saws, parallel arm saws and C-arm saws. The parallel arm saws cut with a precise up and down motion with the blade vertical throughout the cutting stroke. C-arm saws have a slight front to back oscillation in their cutting stroke. C-arm saws are less expensive, but are much less accurate for detail work. Look for the parallel arm saws in the top-end brands. As with all tool purchases, buy the best tool you can afford and save money buying a used machine in good shape if you possibly can. Any inexpensive tool will prove to be the more expensive in the long run because you'll be buying it or a replacement in short order. 
 
For an example of the savings available on a used top of the line machine, see: Sakura 14" Scroll Mate Saw S/N 8807020923 | eBay and 21" Scroll Mate Scroll Saw | eBay   The former lists new for $549 (14" SCROLL SAW - PS Wood Machines ) and the latter lists new for $799. 21" PS WOOD SCROLL SAW - PS Wood Machines
 
 

Thank you once again for clearing the means of applying the viewing distance and for explaining how the copper plates are fastened to the hull and it is in fact the vessels iron bolts acting as the anode in electrolysis and this now makes perfect sense to me as Modern day steel vessels have a similar problem and use zinc bars attached to the hull to act as sacrificial anodes to protect the hull. shafts etc. from electrolysis 

You have to consider the "scale viewing distance." How far back from the full-size vessel would you have to stand to see the entire vessel from stem to stern. Measure something the length of the vessel and get the number from that. Then do your "full-size" test panels as you have and stand as far away from them as you would have to stand off from the full-sized model to see it all at one time within your field of vision. Reproduce what your full-size test panels look like at the "scale viewing distance" above on your model's hull. Don't expect to see anything near the detail you've got at full-size viewing distance up close.
 
I doubt copper plates were ever fastened with iron nails. If they ever were, you can bet it wasn't for long for the reasons stated. Copper plates were fastened with copper "tacks," much like copper flashing on a roofing job. The iron electrolysis problems with coppered bottoms involved the iron fastenings of the ship's hull timbers themselves. Signs of rust wouldn't generally be a major visual feature of a coppered bottom. 
 
Weed growth was little deterred by copper sheathing, although continual sailing scoured the bottom pretty well. Weed growth was (is) most pronounced around the waterline where the sunlight penetrates. Weed growth diminishes as the turn of the bilge is reached and the hull surface is shaded by the hull above. When a vessel is hauled, this weed and algae growth is immediately removed by hosing or scraping, which is easily accomplished. Once it dries, it is much more difficult to remove. In tropical waters, bottom fouling could quickly become excessive, particularly if the vessel was not actively sailing for any period of time. Ships were generally careened whenever possible, even if just upon shore, in order to maintain a much faster and maneuverable vessel. 

You've got it! All those samples look great. I couldn't tell them apart from a close-up look at the real thing. Just remember to consider the scale viewing distance when applying those techniques to a model hull. Look at your samples from a distance to see the difference between close up full-scale and whatever scale your model is and adjust your detail accoordingly.

True that, Roger, but there's a lot of difference between wood species that will be encountered. A hardwood gun stock of walnut, for example, will not "whisker" much at all. On the other hand, a piece of soft basswood will "whisker" a lot over repeated wettings. Sealing any wood with shellac will harden the surface of the wood and subsequent sanding to remove "whiskers," "fuzz," or raised grain will then only need to be done once, rather than repeatedly until there's no more grain rising when the wood is wetted. 

You have to consider the "scale viewing distance." How far back from the full-size vessel would you have to stand to see the entire vessel from stem to stern. Measure something the length of the vessel and get the number from that. Then do your "full-size" test panels as you have and stand as far away from them as you would have to stand off from the full-sized model to see it all at one time within your field of vision. Reproduce what your full-size test panels look like at the "scale viewing distance" above on your model's hull. Don't expect to see anything near the detail you've got at full-size viewing distance up close.
 
I doubt copper plates were ever fastened with iron nails. If they ever were, you can bet it wasn't for long for the reasons stated. Copper plates were fastened with copper "tacks," much like copper flashing on a roofing job. The iron electrolysis problems with coppered bottoms involved the iron fastenings of the ship's hull timbers themselves. Signs of rust wouldn't generally be a major visual feature of a coppered bottom. 
 
Weed growth was little deterred by copper sheathing, although continual sailing scoured the bottom pretty well. Weed growth was (is) most pronounced around the waterline where the sunlight penetrates. Weed growth diminishes as the turn of the bilge is reached and the hull surface is shaded by the hull above. When a vessel is hauled, this weed and algae growth is immediately removed by hosing or scraping, which is easily accomplished. Once it dries, it is much more difficult to remove. In tropical waters, bottom fouling could quickly become excessive, particularly if the vessel was not actively sailing for any period of time. Ships were generally careened whenever possible, even if just upon shore, in order to maintain a much faster and maneuverable vessel. 

You have to consider the "scale viewing distance." How far back from the full-size vessel would you have to stand to see the entire vessel from stem to stern. Measure something the length of the vessel and get the number from that. Then do your "full-size" test panels as you have and stand as far away from them as you would have to stand off from the full-sized model to see it all at one time within your field of vision. Reproduce what your full-size test panels look like at the "scale viewing distance" above on your model's hull. Don't expect to see anything near the detail you've got at full-size viewing distance up close.
 
I doubt copper plates were ever fastened with iron nails. If they ever were, you can bet it wasn't for long for the reasons stated. Copper plates were fastened with copper "tacks," much like copper flashing on a roofing job. The iron electrolysis problems with coppered bottoms involved the iron fastenings of the ship's hull timbers themselves. Signs of rust wouldn't generally be a major visual feature of a coppered bottom. 
 
Weed growth was little deterred by copper sheathing, although continual sailing scoured the bottom pretty well. Weed growth was (is) most pronounced around the waterline where the sunlight penetrates. Weed growth diminishes as the turn of the bilge is reached and the hull surface is shaded by the hull above. When a vessel is hauled, this weed and algae growth is immediately removed by hosing or scraping, which is easily accomplished. Once it dries, it is much more difficult to remove. In tropical waters, bottom fouling could quickly become excessive, particularly if the vessel was not actively sailing for any period of time. Ships were generally careened whenever possible, even if just upon shore, in order to maintain a much faster and maneuverable vessel. 

You've got it! All those samples look great. I couldn't tell them apart from a close-up look at the real thing. Just remember to consider the scale viewing distance when applying those techniques to a model hull. Look at your samples from a distance to see the difference between close up full-scale and whatever scale your model is and adjust your detail accoordingly.

You've got it! All those samples look great. I couldn't tell them apart from a close-up look at the real thing. Just remember to consider the scale viewing distance when applying those techniques to a model hull. Look at your samples from a distance to see the difference between close up full-scale and whatever scale your model is and adjust your detail accoordingly.

You've got it! All those samples look great. I couldn't tell them apart from a close-up look at the real thing. Just remember to consider the scale viewing distance when applying those techniques to a model hull. Look at your samples from a distance to see the difference between close up full-scale and whatever scale your model is and adjust your detail accoordingly.

You've got it! All those samples look great. I couldn't tell them apart from a close-up look at the real thing. Just remember to consider the scale viewing distance when applying those techniques to a model hull. Look at your samples from a distance to see the difference between close up full-scale and whatever scale your model is and adjust your detail accoordingly.

Oh, it is. It is! A search on eBay for "kitch" yields 5,100 results. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p3519243.m570.l1313&_nkw=Kitch&_sacat=0  eBay currently lists 1,200 paintings on black velvet. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=black+velvet+paintings&_sacat=0&LH_TitleDesc=0&_odkw=Kitch&_osacat=0 
 
eBay even lists 623 "antique ship models." https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=antique+ship+models&_sacat=0&LH_TitleDesc=0&_odkw=black+velvet+paintings&_osacat=0 
 
One of those models is listed for the "buy it now" price of $75,000! https://www.ebay.com/itm/265168202451?hash=item3dbd41aad3:g:YXEAAOSwx2hgqCyy&amdata=enc%3AAQAHAAAAoHpjbFabjApK75gjwupuZ1vr%2FtskwUWQp0bZXbtgrvmAEpG0g%2BW9oEs7ZTsF42c%2Bz0u%2FBGcaSTNRpFQm7E1V4F7AQBJfC49dpOd3J5yj6EHa5c5O%2FRSqpwjsNGVCroMG4HuP%2FyKSDOj1kAoZ1f5ZaHlvdHqo6wzUCUL1y8yAhJPhYxOWsz13nyrFMou7q%2BfmG8ex5vAG0ppYQxQpeN5hgOs%3D|tkp%3ABk9SR-7L24bHYQ
 
That said, the model Jaager and ccoyle accurately commented about isn't in the $75,000 category at all. What is asked on eBay and what is realized are often quite different figures.  The moral of the story is that any antique (by definition over 100 year old) ship model is worth whatever a willing buyer will pay to a willing seller. If you like it for whatever reason, cherish and enjoy it as a family heirloom. It's a rare home that won't have its decor improved by a ship model on display! 
 
 
 
 

Oh, it is. It is! A search on eBay for "kitch" yields 5,100 results. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p3519243.m570.l1313&_nkw=Kitch&_sacat=0  eBay currently lists 1,200 paintings on black velvet. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=black+velvet+paintings&_sacat=0&LH_TitleDesc=0&_odkw=Kitch&_osacat=0 
 
eBay even lists 623 "antique ship models." https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=antique+ship+models&_sacat=0&LH_TitleDesc=0&_odkw=black+velvet+paintings&_osacat=0 
 
One of those models is listed for the "buy it now" price of $75,000! https://www.ebay.com/itm/265168202451?hash=item3dbd41aad3:g:YXEAAOSwx2hgqCyy&amdata=enc%3AAQAHAAAAoHpjbFabjApK75gjwupuZ1vr%2FtskwUWQp0bZXbtgrvmAEpG0g%2BW9oEs7ZTsF42c%2Bz0u%2FBGcaSTNRpFQm7E1V4F7AQBJfC49dpOd3J5yj6EHa5c5O%2FRSqpwjsNGVCroMG4HuP%2FyKSDOj1kAoZ1f5ZaHlvdHqo6wzUCUL1y8yAhJPhYxOWsz13nyrFMou7q%2BfmG8ex5vAG0ppYQxQpeN5hgOs%3D|tkp%3ABk9SR-7L24bHYQ
 
That said, the model Jaager and ccoyle accurately commented about isn't in the $75,000 category at all. What is asked on eBay and what is realized are often quite different figures.  The moral of the story is that any antique (by definition over 100 year old) ship model is worth whatever a willing buyer will pay to a willing seller. If you like it for whatever reason, cherish and enjoy it as a family heirloom. It's a rare home that won't have its decor improved by a ship model on display! 
 
 
 
 

Oh, it is. It is! A search on eBay for "kitch" yields 5,100 results. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p3519243.m570.l1313&_nkw=Kitch&_sacat=0  eBay currently lists 1,200 paintings on black velvet. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=black+velvet+paintings&_sacat=0&LH_TitleDesc=0&_odkw=Kitch&_osacat=0 
 
eBay even lists 623 "antique ship models." https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=antique+ship+models&_sacat=0&LH_TitleDesc=0&_odkw=black+velvet+paintings&_osacat=0 
 
One of those models is listed for the "buy it now" price of $75,000! https://www.ebay.com/itm/265168202451?hash=item3dbd41aad3:g:YXEAAOSwx2hgqCyy&amdata=enc%3AAQAHAAAAoHpjbFabjApK75gjwupuZ1vr%2FtskwUWQp0bZXbtgrvmAEpG0g%2BW9oEs7ZTsF42c%2Bz0u%2FBGcaSTNRpFQm7E1V4F7AQBJfC49dpOd3J5yj6EHa5c5O%2FRSqpwjsNGVCroMG4HuP%2FyKSDOj1kAoZ1f5ZaHlvdHqo6wzUCUL1y8yAhJPhYxOWsz13nyrFMou7q%2BfmG8ex5vAG0ppYQxQpeN5hgOs%3D|tkp%3ABk9SR-7L24bHYQ
 
That said, the model Jaager and ccoyle accurately commented about isn't in the $75,000 category at all. What is asked on eBay and what is realized are often quite different figures.  The moral of the story is that any antique (by definition over 100 year old) ship model is worth whatever a willing buyer will pay to a willing seller. If you like it for whatever reason, cherish and enjoy it as a family heirloom. It's a rare home that won't have its decor improved by a ship model on display! 
 
 
 
 

Most of the stuff I know was learned from making mistakes!    

If you are talking about pinning planking, it is really unnecessary if the planks are properly tapered and pre-shaped by spiling or using the heated edge bend method shown in the four part Chuck Passaro YouTube videos.  Consider studying the videos and the planking tutorial in the Articles database here at MSW by David Antscherl.  The results from both methods are of the highest order in terms of quality and realism.   
 
Allan

The advice to "buy ahead", getting a kit you might be interested in someday so you have it on hand as inspiration, comes with a caveat. Hobbies move forward and develop, and if you wait too long, you may end up with an outdated kit. Model ship kit design has progressed amazingly in the last decade, at least among the more conscientious, forward-thinking manufacturers, to the point that older kits can feel impossibly clunky in comparison (poor materials, poor instructions, etc.). This is similar to other hobbies like model railroading. If you come back to that now, after dabbling in, say, the '90s, you probably won't want your old '90s trains from their dusty box in the closet, because their quality is so much worse and the options available now are so much better in every respect (except one, which I'm about to get to).
 
People also change. You may be sure now that you want to build a USS Constitution someday, but after a couple years in the hobby working your way up, you may develop a fascination with steamboats or aircraft carriers or Chinese fishing boats, and you'll want that money and shelf space back. Or, as Roger suggested, you may end up diving into scratchbuilding and never going back to kits. 
 
The caveat here is price. Kits go up in price just like everything else over time, and you may well be better off buying something now for ten years later, IF you're sure it's something you'll want and build ten years from now. If not, if it just ends up on a shelf destined for eBay or the dumpster someday, it may not be worth it. Don't make your kids clean out your closet full of unbuilt kits.
 
So my strong advice is that, at whatever rate you progress, go one model at a time, whether it's a big jump or a little one.
 
What helped me most in my progression wasn't necessarily developing physical skills, as important as that was, but rather developing a mental understanding of the history and engineering of vessel design. My first scratchbuilt steamboat model was terrible (at least below the main deck) because I had no idea how hulls worked and hadn't tried to understand (just plowed ahead ignorant), so just made it like a barge. After that, I took a deep dive into the history of steamboat development and design, and once I actually understood the vessels, was able to make much better models. The same was true for other projects: even doing a basic Viking ship kit, I took the time to research and understand how and why these ships were built, which let me apply and develop skills toward improving that kit. Building a revenue cutter, I worked to understand rigging and was able to make significant improvements to the kit's rigging plan. The bonus is that I value each project more when I understand it, and it isn't just a shallow display piece.
 
To again use model railroading as an example, even more important than physical modeling skill is an intellectual understanding of how railroads work. If you can design a layout that will "feel" real and represent realistic railroad operations (whether complex or simple), and if you understand which equipment goes together, you'll likely enjoy the hobby more than just running trains in a circle, no matter how good your scenery and weathering are.
 
So to summarize this long-winded post, in my opinion the most important skill to develop is intellectual curiosity, and that should be applied one project at a time to allow for a flexible future and a minimum of waste.

No kidding! Don'tcha just hate waking up in a cold sweat dreaming about that "rare, but life-threatening infection in the skin of the perineum?"  

Welcome to MSW Doug,
 
Are you speaking of European boxwood or castello boxwood, which is a wonderful wood with which to work? Take Bob's post seriously.  If you're going to be painting the hull, consider something like poplar or basswood.  I predominantly use castello boxwood for period ships that are not painted, but for schooners and such that will be painted, it is not necessary to go to the expense if you don't want to.  
 
As to figuring the amount of lumber, look at the amount of space from keel to the top of the futtocks at midships.   Multiply times the length, then double it to cover port and starboard.  Add another 20% for mistakes and waste if buying planks. In the long run  I agree with Bob in that it is better to buy billets of timber and cutting it to size.  The waste in sawdust is high but it is the same for anyone supplying finished planking so you will be paying for the wood plus the labor that goes into it.   It only takes a few models to get your money back on a good saw and thickness sander with the savings.  If you are not sure, calculate what you need then price billets versus pre-cut planking.   You can then figure the return on investment on the equipment.    Boxwood, be it European or castello, is getting more difficult to find.  When my stock runs out may be looking at Alaskan cedar billets as well.    BTW, Castello is not really a true boxwood but it really is super to work with.
 
Allan
 
 

Hey, welcome to the forum! Before anybody else does, let me suggest you go to the "new members" section and "introduce yourself," if you haven't already. 
 
I had some time on my hands and figured I'd respond to your question by sharing some thoughts on making the transition from model kit assembly to model building from scratch. Each approach has it's advantages and amazing work is done by many in both instances. it seems to be a natural progression, however, that folks begin with kits, then start supplementing their kit builds with aftermarket parts, then begin "kit bashing," and finally make the quantum leap to scratch building or what is known in the trade as "The Dark Side." The biggest difference between kit building and scratch building, as you've now discovered, whether you realize it or not, is that when scratch-building, the modeler must 'front load" his work with all the plans required, including translating plans for full-sized construction to plans for scale model construction, compiling materials lists, as you've encountered here, and so on. I'd guess the scratch builder puts as much time into historical research, drafting, tool acquisition, and shop management, as goes into the actual building process itself. If one doesn't have a taste for these tasks, they will probably enjoy greater satisfaction staying with with kit building.
 
Since you mention planking with boxwood, I presume you are contemplating finishing the hull bright and showing all the plank seams. First off, you may want to reconsider using boxwood for planking after you price the stuff. There is a lot of waste involved in planking, although the offcuts will be useful for other purposes of the build. Boxwood can be stiff and difficult to bend, as well. Clear, fine grained Alaskan Yellow Cedar comes close in appearance and is easier to work with and considerably less expensive. (See: https://thenrg.org/resources/Documents/articles/AnOverviewOfWoodProperties.pdf)
 
The method of planking is the first consideration. Do you plan to edge-set a lot of your planks as in the method described by master-modeler Chuck Passaro of this forum (and owner of Syren Shipmodel Company) or more traditional spiled plank? See: https://modelshipworld.com/forum/98-planking-downloads-and-tutorials-and-videos/) Chuck's method is much more economical in terms of wood requirements, but may not be suitable for all planks in a wineglass-sectioned hull like a J Boat.  A hull with a lot of "tuck" may also require planking stock of varying thicknesses to accommodate "backing out" and "rounding off" to achieve the sharp frame curves aft. (This process involves carving a convex or concave face on the plank so it will lay fair against the faying surface of a sharply curved frame and fairly follow the outboard curve.) I suggest you read up on planking technique to learn to visualize plank shapes and understand how to spile plank to develop the proper plank shapes necessary. (See:https://thenrg.org/resources/Documents/articles/LiningOffYourHullPlankingTutorialAndFan.pdf) Some planks must be cut from substantially wide stock to accommodate the plank's curved shape. The scale of the model will dictate the plank lengths and widths. If you plan to show the plank seams as is the case with bright-finished hulls, you will need more plank to replicate full-size planking at scale. if you are simply "planking" to attain the shape of the hull and then paint it, you'll have more latitude in "skinning" the hull. For these reasons, the answer to the question of how much planking stock you may need is, "It depends." Not a real helpful answer, I know. 
 
You're talking about a good-sized model of 48". I'm guessing the scale is somewhere around 1:36 (1 inch equals about 3 feet.) If you put a rig on the model, it will stand about seven feet tall. Are you talking about a sailing model or a display model? At a scale that large, your build will probably require planking in the same manner as full-size practice. You will have to "line off" your planking and spile the planks to shape no matter how you cut it. You might as well get out your drawing board and do your spiling on paper to determine your maximum planking widths and scale lengths. This will provide you with a pretty good idea of the amount and size of planking stock you'll require to plank the hull. I'd add 25 to 50% additional to the planked area of the hull for off-cut waste and "goofs." With this sort of build, you will be better off milling your stock on an "as needed" basis than trying to source expensive pre-milled stock from the various vendors. 
 
As a practical matter, particularly for a build the size you contemplate, I'd think you'd be well-advised to invest in the Byrnes Model Tools "trifecta, their  table saw, thickness planer, and disk sander, (http://www.byrnesmodelmachines.com/index5.html), a decent scroll saw at the least, if not additionally a "14 bandsaw or a 10" table saw, and think in terms of buying your wood in fair sized billets and milling it yourself. (See: https://thenrg.org/resources/Documents/articles/MillingScaleLumber.pdf) These tools aren't inexpensive but they hold their value pretty well and can always be sold if you lose interest in the hobby and the savings you will realize milling your own stock will substantially defray their purchase cost. There are those, and more power to them, who will say that the great Navy Board Models in museums were built with hand tools (which isn't entirely true) and all you need is a coping saw and an x-acto knife and you're good to go. It is true some remarkable models have been built with remarkably primitive tools, but the reality is that the level of accuracy modelers aspire to today, and the time it takes to scratch-build a model, benefit greatly from a limited number of specialized power tools which can eliminate a lot of the tedium and drudgery which otherwise can go with the territory. (See: https://thenrg.org/articles/power-tools)
 
Building an "as built" large scale model from scratch can be a daunting task, but, like any project, easy enough if it's broken into discrete steps and care is taken to do the best work possible on each step. It should be said, though, that unlike running shoes, advising a beginning modeler to "Just do it!" is more often a recipe for disappointment. A large scale J Boat can be a beautiful thing. They have remarkably graceful hulls. (Their tall rigs will often chase everybody out of the room when they're finished, though. )  I'd encourage you to begin and build upon what you've learned from your first model, but do it right and avoid the pitfalls that can take all the fun out of the enterprise in short order if you don't plan each process carefully in advance and...
 

Hey, welcome to the forum! Before anybody else does, let me suggest you go to the "new members" section and "introduce yourself," if you haven't already. 
 
I had some time on my hands and figured I'd respond to your question by sharing some thoughts on making the transition from model kit assembly to model building from scratch. Each approach has it's advantages and amazing work is done by many in both instances. it seems to be a natural progression, however, that folks begin with kits, then start supplementing their kit builds with aftermarket parts, then begin "kit bashing," and finally make the quantum leap to scratch building or what is known in the trade as "The Dark Side." The biggest difference between kit building and scratch building, as you've now discovered, whether you realize it or not, is that when scratch-building, the modeler must 'front load" his work with all the plans required, including translating plans for full-sized construction to plans for scale model construction, compiling materials lists, as you've encountered here, and so on. I'd guess the scratch builder puts as much time into historical research, drafting, tool acquisition, and shop management, as goes into the actual building process itself. If one doesn't have a taste for these tasks, they will probably enjoy greater satisfaction staying with with kit building.
 
Since you mention planking with boxwood, I presume you are contemplating finishing the hull bright and showing all the plank seams. First off, you may want to reconsider using boxwood for planking after you price the stuff. There is a lot of waste involved in planking, although the offcuts will be useful for other purposes of the build. Boxwood can be stiff and difficult to bend, as well. Clear, fine grained Alaskan Yellow Cedar comes close in appearance and is easier to work with and considerably less expensive. (See: https://thenrg.org/resources/Documents/articles/AnOverviewOfWoodProperties.pdf)
 
The method of planking is the first consideration. Do you plan to edge-set a lot of your planks as in the method described by master-modeler Chuck Passaro of this forum (and owner of Syren Shipmodel Company) or more traditional spiled plank? See: https://modelshipworld.com/forum/98-planking-downloads-and-tutorials-and-videos/) Chuck's method is much more economical in terms of wood requirements, but may not be suitable for all planks in a wineglass-sectioned hull like a J Boat.  A hull with a lot of "tuck" may also require planking stock of varying thicknesses to accommodate "backing out" and "rounding off" to achieve the sharp frame curves aft. (This process involves carving a convex or concave face on the plank so it will lay fair against the faying surface of a sharply curved frame and fairly follow the outboard curve.) I suggest you read up on planking technique to learn to visualize plank shapes and understand how to spile plank to develop the proper plank shapes necessary. (See:https://thenrg.org/resources/Documents/articles/LiningOffYourHullPlankingTutorialAndFan.pdf) Some planks must be cut from substantially wide stock to accommodate the plank's curved shape. The scale of the model will dictate the plank lengths and widths. If you plan to show the plank seams as is the case with bright-finished hulls, you will need more plank to replicate full-size planking at scale. if you are simply "planking" to attain the shape of the hull and then paint it, you'll have more latitude in "skinning" the hull. For these reasons, the answer to the question of how much planking stock you may need is, "It depends." Not a real helpful answer, I know. 
 
You're talking about a good-sized model of 48". I'm guessing the scale is somewhere around 1:36 (1 inch equals about 3 feet.) If you put a rig on the model, it will stand about seven feet tall. Are you talking about a sailing model or a display model? At a scale that large, your build will probably require planking in the same manner as full-size practice. You will have to "line off" your planking and spile the planks to shape no matter how you cut it. You might as well get out your drawing board and do your spiling on paper to determine your maximum planking widths and scale lengths. This will provide you with a pretty good idea of the amount and size of planking stock you'll require to plank the hull. I'd add 25 to 50% additional to the planked area of the hull for off-cut waste and "goofs." With this sort of build, you will be better off milling your stock on an "as needed" basis than trying to source expensive pre-milled stock from the various vendors. 
 
As a practical matter, particularly for a build the size you contemplate, I'd think you'd be well-advised to invest in the Byrnes Model Tools "trifecta, their  table saw, thickness planer, and disk sander, (http://www.byrnesmodelmachines.com/index5.html), a decent scroll saw at the least, if not additionally a "14 bandsaw or a 10" table saw, and think in terms of buying your wood in fair sized billets and milling it yourself. (See: https://thenrg.org/resources/Documents/articles/MillingScaleLumber.pdf) These tools aren't inexpensive but they hold their value pretty well and can always be sold if you lose interest in the hobby and the savings you will realize milling your own stock will substantially defray their purchase cost. There are those, and more power to them, who will say that the great Navy Board Models in museums were built with hand tools (which isn't entirely true) and all you need is a coping saw and an x-acto knife and you're good to go. It is true some remarkable models have been built with remarkably primitive tools, but the reality is that the level of accuracy modelers aspire to today, and the time it takes to scratch-build a model, benefit greatly from a limited number of specialized power tools which can eliminate a lot of the tedium and drudgery which otherwise can go with the territory. (See: https://thenrg.org/articles/power-tools)
 
Building an "as built" large scale model from scratch can be a daunting task, but, like any project, easy enough if it's broken into discrete steps and care is taken to do the best work possible on each step. It should be said, though, that unlike running shoes, advising a beginning modeler to "Just do it!" is more often a recipe for disappointment. A large scale J Boat can be a beautiful thing. They have remarkably graceful hulls. (Their tall rigs will often chase everybody out of the room when they're finished, though. )  I'd encourage you to begin and build upon what you've learned from your first model, but do it right and avoid the pitfalls that can take all the fun out of the enterprise in short order if you don't plan each process carefully in advance and...
 

Hey, welcome to the forum! Before anybody else does, let me suggest you go to the "new members" section and "introduce yourself," if you haven't already. 
 
I had some time on my hands and figured I'd respond to your question by sharing some thoughts on making the transition from model kit assembly to model building from scratch. Each approach has it's advantages and amazing work is done by many in both instances. it seems to be a natural progression, however, that folks begin with kits, then start supplementing their kit builds with aftermarket parts, then begin "kit bashing," and finally make the quantum leap to scratch building or what is known in the trade as "The Dark Side." The biggest difference between kit building and scratch building, as you've now discovered, whether you realize it or not, is that when scratch-building, the modeler must 'front load" his work with all the plans required, including translating plans for full-sized construction to plans for scale model construction, compiling materials lists, as you've encountered here, and so on. I'd guess the scratch builder puts as much time into historical research, drafting, tool acquisition, and shop management, as goes into the actual building process itself. If one doesn't have a taste for these tasks, they will probably enjoy greater satisfaction staying with with kit building.
 
Since you mention planking with boxwood, I presume you are contemplating finishing the hull bright and showing all the plank seams. First off, you may want to reconsider using boxwood for planking after you price the stuff. There is a lot of waste involved in planking, although the offcuts will be useful for other purposes of the build. Boxwood can be stiff and difficult to bend, as well. Clear, fine grained Alaskan Yellow Cedar comes close in appearance and is easier to work with and considerably less expensive. (See: https://thenrg.org/resources/Documents/articles/AnOverviewOfWoodProperties.pdf)
 
The method of planking is the first consideration. Do you plan to edge-set a lot of your planks as in the method described by master-modeler Chuck Passaro of this forum (and owner of Syren Shipmodel Company) or more traditional spiled plank? See: https://modelshipworld.com/forum/98-planking-downloads-and-tutorials-and-videos/) Chuck's method is much more economical in terms of wood requirements, but may not be suitable for all planks in a wineglass-sectioned hull like a J Boat.  A hull with a lot of "tuck" may also require planking stock of varying thicknesses to accommodate "backing out" and "rounding off" to achieve the sharp frame curves aft. (This process involves carving a convex or concave face on the plank so it will lay fair against the faying surface of a sharply curved frame and fairly follow the outboard curve.) I suggest you read up on planking technique to learn to visualize plank shapes and understand how to spile plank to develop the proper plank shapes necessary. (See:https://thenrg.org/resources/Documents/articles/LiningOffYourHullPlankingTutorialAndFan.pdf) Some planks must be cut from substantially wide stock to accommodate the plank's curved shape. The scale of the model will dictate the plank lengths and widths. If you plan to show the plank seams as is the case with bright-finished hulls, you will need more plank to replicate full-size planking at scale. if you are simply "planking" to attain the shape of the hull and then paint it, you'll have more latitude in "skinning" the hull. For these reasons, the answer to the question of how much planking stock you may need is, "It depends." Not a real helpful answer, I know. 
 
You're talking about a good-sized model of 48". I'm guessing the scale is somewhere around 1:36 (1 inch equals about 3 feet.) If you put a rig on the model, it will stand about seven feet tall. Are you talking about a sailing model or a display model? At a scale that large, your build will probably require planking in the same manner as full-size practice. You will have to "line off" your planking and spile the planks to shape no matter how you cut it. You might as well get out your drawing board and do your spiling on paper to determine your maximum planking widths and scale lengths. This will provide you with a pretty good idea of the amount and size of planking stock you'll require to plank the hull. I'd add 25 to 50% additional to the planked area of the hull for off-cut waste and "goofs." With this sort of build, you will be better off milling your stock on an "as needed" basis than trying to source expensive pre-milled stock from the various vendors. 
 
As a practical matter, particularly for a build the size you contemplate, I'd think you'd be well-advised to invest in the Byrnes Model Tools "trifecta, their  table saw, thickness planer, and disk sander, (http://www.byrnesmodelmachines.com/index5.html), a decent scroll saw at the least, if not additionally a "14 bandsaw or a 10" table saw, and think in terms of buying your wood in fair sized billets and milling it yourself. (See: https://thenrg.org/resources/Documents/articles/MillingScaleLumber.pdf) These tools aren't inexpensive but they hold their value pretty well and can always be sold if you lose interest in the hobby and the savings you will realize milling your own stock will substantially defray their purchase cost. There are those, and more power to them, who will say that the great Navy Board Models in museums were built with hand tools (which isn't entirely true) and all you need is a coping saw and an x-acto knife and you're good to go. It is true some remarkable models have been built with remarkably primitive tools, but the reality is that the level of accuracy modelers aspire to today, and the time it takes to scratch-build a model, benefit greatly from a limited number of specialized power tools which can eliminate a lot of the tedium and drudgery which otherwise can go with the territory. (See: https://thenrg.org/articles/power-tools)
 
Building an "as built" large scale model from scratch can be a daunting task, but, like any project, easy enough if it's broken into discrete steps and care is taken to do the best work possible on each step. It should be said, though, that unlike running shoes, advising a beginning modeler to "Just do it!" is more often a recipe for disappointment. A large scale J Boat can be a beautiful thing. They have remarkably graceful hulls. (Their tall rigs will often chase everybody out of the room when they're finished, though. )  I'd encourage you to begin and build upon what you've learned from your first model, but do it right and avoid the pitfalls that can take all the fun out of the enterprise in short order if you don't plan each process carefully in advance and...
 

No kidding! Don'tcha just hate waking up in a cold sweat dreaming about that "rare, but life-threatening infection in the skin of the perineum?"  

Recognizing that I may be sticking my neck out here, I'll offer the comment that the warnings seen on many solvent-based materials these days exist more for the manufacturer's' protection against products liability lawsuits which often result from the misuse of the product than for the protection of folks who use the product "as directed for the use intended." If you read the warnings now printed on a common ladder, you'd never climb one again. This phenomenon has created a certain level of paranoia in the general public, many of whom shy away from anything that has an odor they've been conditioned to find disagreeable. While chemistry continues to make progress in developing non-solvent-based materials, in most instances these substitute "water-based" materials intended to replace long-established solvent-based materials are inferior to their solvent-based predecessors, particularly with respect to their archival qualities, an important consideration in modeling. When used as directed, meaning "in a well-ventilated workspace" and in the small amounts encountered in modeling, there is generally negligible risk in using solvent-based materials. Commonsense is the order of the day in this respect. Without question, pouring an excessive amount of solvent-based material in a paper bag and "huffing" it is hazardous to your health, but we aren't contemplating that sort of misuse. Sadly, the general public's conditioned reaction to these product warnings has reduced the marketability of valuable materials and chased many manufacturers out of the marketplace entirely. (The demise of Floquil paints being a prime example.) In jurisdictions like California, which requires warning labels on anything that "may cause cancer or birth defects," we find state-mandated warning labels to that effect on everything from gasoline to wine and many long-valued solvent-based products can no longer be legally purchased at all. Local "product safety" ordinances in some California "air quality districts" even go so far as to outlaw the sale of any volatile organic compounds above a certain content limit including simple oil-based enamel paint or paint thinner and the like and, consequently, all that can be purchased anymore are inferior water-based coatings. Mindfulness of shop safety is a good thing, but we should not "throw the baby out with the bath water." Otherwise, we will continue to find valuable materials becoming entirely unavailable to the detriment of our craft.
 
That said, Bondo is a hygroscopic material intended for use on dented automotive body metal and is not intended for nor suitable for use on wooden surfaces.