1st scratch build. Which wood

[Riotvan88]

Hi guys I'm doing my first scratch build of Zwarte zee tug. I'm guessing the frames should be 5mm plywood? I've noticed many different woods available on Cornwall model boats site. Is ply sufficient for frame or should they be hardwood? 

 

Also for planking what should be used considering the planking won't be visable like a period ship.  Cheap strip wood or walnut/cherry? I'm guessing the expensive strip wood would be used for a period ship where the planks are decorative? 

 

Cheers

Guys

[Jaager]

If this is a steel vessel -  and POB is your method

 

the molds do not need to be plywood.  Plywood is ugly to work.  The open grain at the edges makes a poor bonding surface.

if you are US -  Home Depot has 1/4" x 2" x 3'  Yellow Poplar for ~$3   using a hand fret saw would be an easy way to free the molds by following the patterns.

1/4" Pine will work - just avoid stock with sap.

For the outside, the paint finish is the most important factor?   Most any wood will do.  Species that do not resist being bent are easier to plank with.

Open pore species such as Oak, Ash, Willow will do, it is just that open pore species require an additional pore filling step for there to be a smooth finish.

A closed grain species does not need a sealer, it just needs a primer.

You may be able to find packages of veneer at Wood Craft as stock to be spilled 

I am not sure just how long term stable is rotary cut veneer is as bent planking.  If bend in the plane that was curved to when sliced is where it is bent, it may be very stable.

 

I think Basswood is too soft and too fuzzy for your purposes.

Pine veneer could be used for the planking - but most species of Pine are easy to dent.

Premium species intended for use as something with a clear finish will do what you wish,  but you will be paying more than is necessary.

 

[Roger Pellett]

While there is a temptation to want to use “the best,” unless you are building an open framed Dockyard style model, the classic ship modeling woods are a waste of money.

 

Do Not use plywood for bulkheads.  By doing so  the working surface becomes the the various veneers and punky “mystery wood” used to laminate the plywood.  While some modelers have had success with  very high quality Baltic Birch plywood this is very different from the usual craft grades available.  Likewise, I would not choose MDF, the staple of many kits today.

 

If you live in the US and have access to a table saw regular construction grade “pine” lumber can be an excellent choice.  In many USA markets this is actually SPF lumber.  This stands for Spruce, Pine, Fir.  For structural members I would choose pine or possibly fir.  Spruce could actually be a nice planking choice as it bends nicely.  It is easily distinguished from the other two. It is whiter in color and has, at least for me, a slightly objectionable odor, not the nice piny smell.

 

True pine is a beautiful wood.  It was the choice of makers of patterns for castings and of professionals building ship models for display and especially for experimental models towed in towing tanks.  In your case, to form bulkheads I would build frames Hahn style laminated from two thinner layers.

 

Selecting your lumber by sorting through  a stack at your local lumberyard to find the right species, and grain orientation can be an enjoyable way to begin your project.  And, since the cost per board ft will be much less than that of a hobby grade material you can afford to buy larger pieces in order to utilize smaller areas with the grain that you are looking for.  Add what’s left over to your stash.

 

Roger

[No Idea]

10 hours ago, Riotvan88 said:

Hi guys I'm doing my first scratch build of Zwarte zee tug. I'm guessing the frames should be 5mm plywood? I've noticed many different woods available on Cornwall model boats site. Is ply sufficient for frame or should they be hardwood? 

 

Also for planking what should be used considering the planking won't be visable like a period ship.  Cheap strip wood or walnut/cherry? I'm guessing the expensive strip wood would be used for a period ship where the planks are decorative? 

 

Cheers

Guys

Where in the world are you based?  If you are in the UK I can give you some details of a decent wood supplier 

[Riotvan88]

12 hours ago, No Idea said:

Where in the world are you based?  If you are in the UK I can give you some details of a decent wood supplier 

I'm in the UK. Have access to a scroll saw and plan to use that cut the frames. The model is planned to be RC if that makes a difference.

 

As others have suggested I'm looking for quality but don't need decorative planking type wood as the ship is steel hull.

[Jaager]

For UK, I have to amend my suggestions:

Yellow Poplar is  an Eastern US native species.  It is about as hard as Lime, but the colors of the wood is harlequin like.

It is best hidden or painted and has no features that would make it worth paying import prices to use.

Poplar is also a name given to wood from members of the Cottonwood family.  Most of the wood from these species is best used as mulch or pulp for paper.  You do not want to mess with it.

Basswood is a brother to Lime/Linden.  It is not near as good as Lime and is about half as hard and more fuzzy.

 

For your interior supports -  1/4" Pine would be strong, but easier to scroll cut.   As Roger suggests, maybe use 1/8" stock, paired and done as timbers with the butt joints overlapping laterally:  do true frames as 1/4" bends -  make it 1/4" frame and 1.4" space.  With a base of 50% wood for the planking, a single layer would be enough.

The moulded dimension can be wider than the frame of a wooden ship would be.   It can be stair like,  but leave a hollow inside for a motor, batteries and a RF receiver as well as ballast.

 

Even more water immersion friendly would be a hull with no spaces between frames. 

Think a sliced loaf of bread - bread and butter  rather than a sliced hoggie roll bread and butter.

 

[Bob Cleek]

10 hours ago, Jaager said:

Even more water immersion friendly would be a hull with no spaces between frames. 

Think a sliced loaf of bread - bread and butter  rather than a sliced hoggie roll bread and butter.

In which case, it would be much easier to slice "lifts" the shape of the waterlines horizontally from the "loaf" instead of vertically. A lot less cutting to do and probably a stronger hull structure than planks on frames. Much faster because much less work. No?

Edited March 11, 2023 by Bob Cleek

[Jaager]

6 hours ago, Bob Cleek said:

In which case, it would be much easier to slice "lifts" the shape of the waterlines horizontally from the "loaf" instead of vertically. A lot less cutting to do and probably a stronger hull structure than planks on frames. Much faster because much less work. No?

You are very likely correct.   I just prefer using a sanding belt/drum with coarse grit on a small assembly.  A large board cut using a chisel or hand plane does not appeal to me.   It is also not a lot different than the work needed to loft a lot of moulds for single layer POB.  Traditional WL based bread and butter needs a change in perspective.

 

The main factor for me is my obsession with POF.   For me, the lofting is the same whether I build with spaces or no spaces,  show the framing or plank over it,  use stylized framing,  use NA or French all bends,  or  (the Fates forbid) use the furkopfta English framing.  By that, I mean decreasing timber siding in the upper works, single filling frames between the bends, shifting out of line top timbers to frame ports.

 

I am much more comfortable with the pattern intervals of Station to Station as opposed to WL to WL.

Edited March 12, 2023 by Jaager

[Bob Cleek]

9 hours ago, Jaager said:

I am much more comfortable with the pattern intervals of Station to Station as opposed to WL to WL.

I hear you on that score, but I think that's just because we're used to dancing with the girl we brought. I was just thinking that this guy is planning to build an R/C model and an old school "bread and butter" lifts hull would probably be a lot easier and stronger than anything else. If the waterlines are cut carefully, it's quite easy to fair up the hull by simply "knocking off the corners" using a chisel, plane, spokeshave, and/or a disk sander and sanding board. 

[Riotvan88]

6 hours ago, Bob Cleek said:

I hear you on that score, but I think that's just because we're used to dancing with the girl we brought. I was just thinking that this guy is planning to build an R/C model and an old school "bread and butter" lifts hull would probably be a lot easier and stronger than anything else. If the waterlines are cut carefully, it's quite easy to fair up the hull by simply "knocking off the corners" using a chisel, plane, spokeshave, and/or a disk sander and sanding board. 

I plan to built POF as that's what the plans I have done as and that's how I've built all previous models. 

 

Am I correct in thinking the method you are discussing creates a hull from several thick layers of wood, each one a cross section through the vertical plane? 

 

The only data I have is in my plans is decks and frames.

[Bob Cleek]

6 hours ago, Riotvan88 said:

Am I correct in thinking the method you are discussing creates a hull from several thick layers of wood, each one a cross section through the vertical plane? 

No. What I'm talking about is exactly the opposite: layers cut to the shape of each waterline shape, stacked on top of one another. i.e. each one a cross section through the horizontal plane. Conseqently, there's a whole lot fewer layers to loft and cut. (In your case, one "lift" for each deck. Not as many as indicated in the video below which is provided for illustrative purposes.)

 

6 hours ago, Riotvan88 said:

The only data I have is in my plans is decks and frames.

The deck shapes are all  you need, together with the distance between each deck.

 

The "bread and butter" lift method is described in detail in this article: Building a Bread-and-Butter Solid Hull Ship Model – The Model Shipwright 

This method is favored for larger models for a variety of reasons and the interiors of hulls constructed in this fashion are easily hollowed out for R/C purposes by cutting away waste wood before assembly of the lifts. 

 

A picture is worth a thousand words department:

 

 

Edited March 12, 2023 by Bob Cleek

[Riotvan88]

On 3/12/2023 at 10:50 PM, Bob Cleek said:

No. What I'm talking about is exactly the opposite: layers cut to the shape of each waterline shape, stacked on top of one another. i.e. each one a cross section through the horizontal plane. Conseqently, there's a whole lot fewer layers to loft and cut. (In your case, one "lift" for each deck. Not as many as indicated in the video below which is provided for illustrative purposes.)

 

The deck shapes are all  you need, together with the distance between each deck.

 

The "bread and butter" lift method is described in detail in this article: Building a Bread-and-Butter Solid Hull Ship Model – The Model Shipwright 

This method is favored for larger models for a variety of reasons and the interiors of hulls constructed in this fashion are easily hollowed out for R/C purposes by cutting away waste wood before assembly of the lifts. 

 

A picture is worth a thousand words department:

 

 

Ok thanks. Would 6mm mahogany sheets be any good for frames? I'm going to use POF simply because that's what I know and the plans are done in that format. It's more work to derive waterlines from my plans. The hull will be finished inside with resin and outside with resin & cloth so I've no concerns it won't be strong enough. 

[Bob Cleek]

Mahogany should work, but keep in mind that most of your frames will likely have to be built up of pieces with their grain orientation going the right way and not simply cut whole from a single piece of sheet stock. Since frames are curved, it's usually impossible to cut a frame from a single piece of wood without grain run-out at some point. This will create very fragile spots in single-thickness frames, the degree of weakness depending upon the grain structure of the wood species used. With the amount of grain run-out you usually get cutting from sheet stock, you'll find yourself busting frames right and left when you try to fair frame faces or even just handle the hull when working on it. Cutting frames from sheet stock can also produce an inordinate amount of waste off-cuts. It's best to make frames of at least doubled pieces so that one half of the doubled frame can bridge the butted ends of the other half so as to reinforce the butts necessary to keep the grain running where it needs to be.

 

I'm not sure that "it's more work to derive waterlines from plans." If you have the shapes of the frames on a "body plan," you've got the waterlines right there in front of you. At each frame you have the distance from the centerline to the inside or outside of the planking (depending upon how the lines were drawn) and you know the distance between the frames. Those points off the centerline and a batten will give you all the waterlines you want, wherever you want. A "bread and butter" hull is a lot easier and faster to make, particularly in larger sizes. Just sayin'.

 

Unless you expect to be spilling a lot of solvent fuel in the bilges, there's no reason to coat the inside of the hull with resin. In the case of a "bread and butter" built hull, there's no reason to sheath the exterior of the hull with glass fabric and resin, either. A good sealer and paint will do just fine to keep the water out. As a practical matter, unless you intend to build an overly thick resin and glass cloth (or mat) sheathing, you aren't going to realize much, if any increase in structural strength adding resin and fabric sheathing to your hull. Sheathing and fairing a good sized hull with resin and cloth is a substantial job with more than a few pitfalls possible along the way.

 

All and all, just my opinions in response to your questions. It's your boat, so do as you please. I'm sure with sufficient care, it will turn out fine however you proceed. Good luck with it!

[Riotvan88]

12 hours ago, Bob Cleek said:

Mahogany should work, but keep in mind that most of your frames will likely have to be built up of pieces with their grain orientation going the right way and not simply cut whole from a single piece of sheet stock. Since frames are curved, it's usually impossible to cut a frame from a single piece of wood without grain run-out at some point. This will create very fragile spots in single-thickness frames, the degree of weakness depending upon the grain structure of the wood species used. With the amount of grain run-out you usually get cutting from sheet stock, you'll find yourself busting frames right and left when you try to fair frame faces or even just handle the hull when working on it. Cutting frames from sheet stock can also produce an inordinate amount of waste off-cuts. It's best to make frames of at least doubled pieces so that one half of the doubled frame can bridge the butted ends of the other half so as to reinforce the butts necessary to keep the grain running where it needs to be.

 

I'm not sure that "it's more work to derive waterlines from plans." If you have the shapes of the frames on a "body plan," you've got the waterlines right there in front of you. At each frame you have the distance from the centerline to the inside or outside of the planking (depending upon how the lines were drawn) and you know the distance between the frames. Those points off the centerline and a batten will give you all the waterlines you want, wherever you want. A "bread and butter" hull is a lot easier and faster to make, particularly in larger sizes. Just sayin'.

 

Unless you expect to be spilling a lot of solvent fuel in the bilges, there's no reason to coat the inside of the hull with resin. In the case of a "bread and butter" built hull, there's no reason to sheath the exterior of the hull with glass fabric and resin, either. A good sealer and paint will do just fine to keep the water out. As a practical matter, unless you intend to build an overly thick resin and glass cloth (or mat) sheathing, you aren't going to realize much, if any increase in structural strength adding resin and fabric sheathing to your hull. Sheathing and fairing a good sized hull with resin and cloth is a substantial job with more than a few pitfalls possible along the way.

 

All and all, just my opinions in response to your questions. It's your boat, so do as you please. I'm sure with sufficient care, it will turn out fine however you proceed. Good luck with it!

Thanks again. Is there any wood type that would allow the whole frame to be cut without doing them in pieces? If I remember correctly the kits I've done were cut in single pieces? 

[Bob Cleek]

1 hour ago, Riotvan88 said:

Thanks again. Is there any wood type that would allow the whole frame to be cut without doing them in pieces? If I remember correctly the kits I've done were cut in single pieces? 

All wood has grain, so the problem of grain run-out on curved shapes is always an inherent weakness. There are some woods that have what is known as interlocked grain and for that reason are less prone to breaking along the grain, but such woods are difficult to work and generally not suitable for modeling work. I'd expect that the kits you are recalling had frames or bulkheads cut from plywood. Plywood doesn't have grain run-out problems because the plies are laminated with the grain running at right angles to each other. The main problem with plywood bulkheads and frames is that the edges of plywood don't take adhesives or mechanical fasteners well at all which causes major headaches when trying to fasten plank to them.

[Jaager]

1 hour ago, Riotvan88 said:

Is there any wood type that would allow the whole frame to be cut without doing them in pieces?

First:  this is not a frame. It is a mold.  The first Italian POB mfg used a term that translated as "bulkhead".  Those parts are not bulkheads.  Western wooden ships did not have bulkheads. Chinese seagoing junks did have actual bulkheads.  But with POB there are no actual frames.  There are no parts that should be called "frames".

 

That the grain for a mold has to support a curve covering as much as 210 degrees is the reason that plywood was first used to make them.  From an esthetic point of view, plywood is a wood product, but not actually wood.  Now another semi synthetic  material: MDF is used by some mfg.  

 

For actual POF, the frame should be made up of timbers.  The timbers should have grain that matched the line of the shape where it lives.    The original builders used compass timbers where there were curves.  This is not really practical for a scale model.  It can be done, but it a lot of work, a lot of luck, and a lot of waste.   An end grain to end grain bond has almost no strength.  A single frame is a breakup waiting to happen.  A pair of frames with timbers that half lap the butt joint of the partner and glue bonded together is very strong.  This is what a 'bend' is.

 

[Riotvan88]

23 minutes ago, Jaager said:

First:  this is not a frame. It is a mold.  The first Italian POB mfg used a term that translated as "bulkhead".  Those parts are not bulkheads.  Western wooden ships did not have bulkheads. Chinese seagoing junks did have actual bulkheads.  But with POB there are no actual frames.  There are no parts that should be called "frames".

 

That the grain for a mold has to support a curve covering as much as 210 degrees is the reason that plywood was first used to make them.  From an esthetic point of view, plywood is a wood product, but not actually wood.  Now another semi synthetic  material: MDF is used by some mfg.  

 

For actual POF, the frame should be made up of timbers.  The timbers should have grain that matched the line of the shape where it lives.    The original builders used compass timbers where there were curves.  This is not really practical for a scale model.  It can be done, but it a lot of work, a lot of luck, and a lot of waste.   An end grain to end grain bond has almost no strength.  A single frame is a breakup waiting to happen.  A pair of frames with timbers that half lap the butt joint of the partner and glue bonded together is very strong.  This is what a 'bend' is.

 

Isn't a mould a solid cross section like the bottom image whilst a frame is a curved structural member as seen in the top image? That was my understanding. Which if correct my model will indeed be POF.

Edited March 15, 2023 by Riotvan88

[Riotvan88]

1 hour ago, Bob Cleek said:

All wood has grain, so the problem of grain run-out on curved shapes is always an inherent weakness. There are some woods that have what is known as interlocked grain and for that reason are less prone to breaking along the grain, but such woods are difficult to work and generally not suitable for modeling work. I'd expect that the kits you are recalling had frames or bulkheads cut from plywood. Plywood doesn't have grain run-out problems because the plies are laminated with the grain running at right angles to each other. The main problem with plywood bulkheads and frames is that the edges of plywood don't take adhesives or mechanical fasteners well at all which causes major headaches when trying to fasten plank to them.

Ok thanks again. My understanding is that I need to create a frame from pieces arranged such that the grain does not run out at the outside edges where the planks will attach. Something like the image attached? And done in pairs with the joints overlapping. 

[oakheart]

Hi Riotvan

 

The tug I am building, an 85 ft Harbour tug designed by Francis Smith, a quick google search will give you loads of ideas.

 

have a look here   https://www.modelboatmayhem.co.uk/forum/index.php/board,126.0.html

there are loads of tugs

https://www.rcgroups.com/forums/showthread.php?3015172-85-foot-Army-ST-Tugboat

 

and this smaller scale  https://www.rcgroups.com/forums/showthread.php?827506-Army-Tug-St-Type

 

I just used some really cheap 4mm ( 1/8" ) plywood for the frames and balsa for planking, as that's what I had 'in stock'

filled in dips with ronseal wood filler and I will GRP ( Resin and cloth ) over the whole hull.

 

Tim 

Edited March 15, 2023 by oakheart

[Jaager]

37 minutes ago, Riotvan88 said:

Which if correct my model will indeed be POF

There is such a thing as sawn frame POF and I guess what you have drawn could be considered to be that.  As fat as you have it drawn, it does not meet the spirit of what POF is though.  You are not after a hull that represents what POF is intended to show anyway, so dealing with definitions  is not relevant.

If you scroll cut that pattern from a Pine plank, it should do what you are after.  If you use a plank of 1/2 the thickness and cut twice as many "frames" but with half if them having an opposite grain orientation, when glue bonded in pairs, it may greatly reduce any breakage.

 

If you use a pattern with alignment holes,  doing it as pairs -  one of the pair could be two pieces - Vertical grain - meeting at the "Y" axis in the center of the keel - two pieces for that frame.  The other be two boards meeting at the "X" axis about halfway up.  The result would be three pieces for that frame.  It would be much easier to cut out the pieces.   Bamboo skewers as dowels = idiot proof orientation if you plan it well.

 

Quote

Something like the image attached? And done in pairs with the joints overlapping. 

 

 

That is essentially the Hahn method.  It may be overkill for a hull meant to float.

Edited March 15, 2023 by Jaager

[Riotvan88]

Would Birch modelling ply be any good? Is that the high quality type ply?

 

https://www.hobbies.co.uk/quality-birch-plywood

 

Otherwise it'll be 3mm mahogany sheets from the model shop and done Hahn style. I'm just cautious of buying expensive finishing/decorative wood unnecessarily for something that's going to be used for hidden internal structure

[Jaager]

35 minutes ago, Riotvan88 said:

Would Birch modelling ply be any good? Is that the high quality type ply?

The Birch is the outside layer.  It is for looks.   It should work as long as it does not get wet.

There is a Birch ply for boat building. The liner ply are not junk and the bonding adhesive is waterproof.   An extreme that you do not need and unlikely to be anywhere as thin as you want.

 

The Mahogany that you can get is not really Mahogany.  Real Mahogany was timbered to near extinction fairly early in the 20th century, so it is a protected species.  I would look real hard for something else.

Most everything called Mahogany has open pores.  This means that it is scale inappropriate if it is on view.

 

Going to a builders supply and getting clear Pine would be a low cost option.  If their thinnest project boards are too thick,  make friends with a serious woodworker and see if he would turn Pine 2x4's or 2x6's into sheets that are your target thickness.

 

[Snug Harbor Johnny]

  Actually ... there is a little 'real' (Honduran) mahogany available by the piece in specialty wood craft stores (those that are left).  The largest is a chain called Woodcraft.  I've heard that there are some South American tree farms that raise exotics for legal import.  One has to pick a piece carefully and then re-saw it yourself.  Now, East Indian Rosewood is completely illegal and not available - but there is a limited quantity of a related Caribbean species. 

[Bob Cleek]

8 hours ago, Riotvan88 said:

Ok thanks again. My understanding is that I need to create a frame from pieces arranged such that the grain does not run out at the outside edges where the planks will attach. Something like the image attached? And done in pairs with the joints overlapping. 

You got it! You can double the frames or you can join the pieces end to end with half-lap joints.

 

Which is why I suggested you build your hull using the "bread and butter" lift method like the majority of working ship model builders do when building a one-off wooden hull, especially for R/C use.

 

From the questions you've been asking, it seems that you may presently lack the breadth of experience and understanding to be attempting to scratch-build an R/C model from plans that by, your description only provide data, on decks and frames. This isn't intended to be a criticism nor to discouraging from building a model ship at all. It's just that a steep flight of stairs isn't the best place to learn to walk. Even with greater experience and skill, you aren't going to get far with incomplete and inadequate plans. I suggest that you consider buying the Billings Boats (kit company) Zwarte Zee tug model kit.  (I've never been a fan of Billings Boats kits, but that's just my personal opinion. Others appear quite satisfied with them.) Billing Boats Zwarte Zee B592 Model Boat Kit | Cornwall Model Boats (I'm not sure, but Billing may have updated their Zwarte Zee kit from a wood hull to a plastic one.) You will get everything you need in the kit (less the R/C running gear, I expect) and, clearly, if you are having problems deciding which wood to use at this point, you have no idea how much trouble you will encounter trying to source other parts for your build (unless you are going to start turning your own from raw brass and copper and soldering the parts together.) You can get the parts from Billings, of course, but it would likely be  very little more money to buy the whole kit than the parts piecemeal and you'd be getting the wood, a complete set of plans, and a set of instructions. As is turns out, Popeye the Sailor of this forum is just commencing a build of the Billings Zwarte Zee tug kit. You can look over his shoulder and learn a lot as he progresses: 

 

Edited March 15, 2023 by Bob Cleek

[Riotvan88]

4 hours ago, Bob Cleek said:

You got it! You can double the frames or you can join the pieces end to end with half-lap joints.

 

Which is why I suggested you build your hull using the "bread and butter" lift method like the majority of working ship model builders do when building a one-off wooden hull, especially for R/C use.

 

From the questions you've been asking, it seems that you may presently lack the breadth of experience and understanding to be attempting to scratch-build an R/C model from plans that by, your description only provide data, on decks and frames. This isn't intended to be a criticism nor to discouraging from building a model ship at all. It's just that a steep flight of stairs isn't the best place to learn to walk. Even with greater experience and skill, you aren't going to get far with incomplete and inadequate plans. I suggest that you consider buying the Billings Boats (kit company) Zwarte Zee tug model kit.  (I've never been a fan of Billings Boats kits, but that's just my personal opinion. Others appear quite satisfied with them.) Billing Boats Zwarte Zee B592 Model Boat Kit | Cornwall Model Boats (I'm not sure, but Billing may have updated their Zwarte Zee kit from a wood hull to a plastic one.) You will get everything you need in the kit (less the R/C running gear, I expect) and, clearly, if you are having problems deciding which wood to use at this point, you have no idea how much trouble you will encounter trying to source other parts for your build (unless you are going to start turning your own from raw brass and copper and soldering the parts together.) You can get the parts from Billings, of course, but it would likely be  very little more money to buy the whole kit than the parts piecemeal and you'd be getting the wood, a complete set of plans, and a set of instructions. As is turns out, Popeye the Sailor of this forum is just commencing a build of the Billings Zwarte Zee tug kit. You can look over his shoulder and learn a lot as he progresses: 

 

Thanks for the advice. I do have some experience and not a total beginner. I've built a Billings smit Rotterdam. Along with a couple of caldercaft models and a scratch built albeit basic  model I built some years ago. For the Rotterdam I replaced most of the fittings with ones I made. So creating the detail parts is no problem.

 

What I'm mostly asking here is what wood is best for the moulds/bulkhead. I've no idea what is used in kits but they didn't involve doubles with joints. Which is why I'm asking simply because whatever wood the kits use seemingly allows one to eliminate that process. I don't want to incur unessesary expense on fine decorative wood and don't want something that isn't up to the task. So hopfully that explains why I'm asking these questions. 

 

I've not been very clear but the plans I have are complete, what I meant by more work was that to do a bread and butter method I'd have to measure each cross section at various heights and record that data to create the waterlines either in drawing form or a list of points to work from. Otherwise I can just cut directly from my plans as is. 

 

The reason I don't want to buy the kit is because it is 1/100 and I want this to be 1/75 and I want to scratch build it.

[Bob Cleek]

3 hours ago, Riotvan88 said:

Thanks for the advice. I do have some experience and not a total beginner. I've built a Billings smit Rotterdam. Along with a couple of caldercaft models and a scratch built albeit basic  model I built some years ago. For the Rotterdam I replaced most of the fittings with ones I made. So creating the detail parts is no problem.

 

What I'm mostly asking here is what wood is best for the moulds/bulkhead. I've no idea what is used in kits but they didn't involve doubles with joints. Which is why I'm asking simply because whatever wood the kits use seemingly allows one to eliminate that process. I don't want to incur unessesary expense on fine decorative wood and don't want something that isn't up to the task. So hopfully that explains why I'm asking these questions. 

 

I've not been very clear but the plans I have are complete, what I meant by more work was that to do a bread and butter method I'd have to measure each cross section at various heights and record that data to create the waterlines either in drawing form or a list of points to work from. Otherwise I can just cut directly from my plans as is. 

 

The reason I don't want to buy the kit is because it is 1/100 and I want this to be 1/75 and I want to scratch build it.

Okay, I've got it. I won't pester you further to go the "bread and butter" route, except to add to what I've said before that buying pine, poplar or the like for a "bread and butter" hull is a lot less expensive than buying pre-milled wood for frames and planking and even considering the time you might take to loft the waterline shapes, it's would be much faster and easier than building the hull plank on frame where you will have to cut out all those individual frames, etc. You're drinking it, though, not me, so pick your poison.   

[Riotvan88]

4 hours ago, Bob Cleek said:

Okay, I've got it. I won't pester you further to go the "bread and butter" route, except to add to what I've said before that buying pine, poplar or the like for a "bread and butter" hull is a lot less expensive than buying pre-milled wood for frames and planking and even considering the time you might take to loft the waterline shapes, it's would be much faster and easier than building the hull plank on frame where you will have to cut out all those individual frames, etc. You're drinking it, though, not me, so pick your poison.   

I do appreciate the advice, just out of interest how thick would the lifts be for a typical bread and butter build?  Wouldn't it require a huge amount of shaping and sanding to go from a blocky form to the final smooth hull form unless one made many thin lifts?

[Bob Cleek]

1 hour ago, Riotvan88 said:

I do appreciate the advice, just out of interest how thick would the lifts be for a typical bread and butter build?  Wouldn't it require a huge amount of shaping and sanding to go from a blocky form to the final smooth hull form unless one made many thin lifts?

The thickness of the lifts are up to the builder. The thicker they are, the more you have to shave off to fair the hull. In a hull like you are contemplating, though, there'd be a lot of flat areas amidships that wouldn't need much fairing at all, which would tend to favor thicker lifts. It's really a question of the size of the hull and how "curvey" it is. Bread and butter construction is more common in larger models. Inch thick lifts would probably work fine on a three or four foot hull. Half-inch lifts would be fine, too, well, but with twice the work to saw them out... and half the work of fairing, more or less. The way they are often made is to only loft the waterline shape from the centerline and use that for a pattern. Two identical halves of a lift are cut out at once from two planks stacked one on top of the other. (These are often screwed together to keep them from moving when the sawing is done.) The "inside" is also cut out of the stacked planks. The pieces are then separated and one turned over and the two glued together at the bow and stern. The result is one whole waterline lift for half the sawing work and the certainty that both sides of the lifts on each side of the hull are identical. The lifts are often cut a bit wide of the line at the bow so the vee of the bow can be faired exactly to the centerline without the risk of over-doing it by accident. If the corners of the lifts that define the shape of the hull are marked with a felt tipped pen or the like, all you do is remove the lift edge that's standing proud and use the black marking to guide you down to as far as the excess needs to be faired. That can be done with a chisel. a spokeshave, or even a pocket knife. When you get close to removing all the excess wood from the lifts, you take a flexible batten with sandpaper glued to it and, bending it to conform to the shape of the hull, sand in all directions to complete the fairing process down to the glue lines marked by the black felt tipped pen ink.

Edited March 16, 2023 by Bob Cleek

[Jaager]

1 hour ago, Bob Cleek said:

The thickness of the lifts are up to the builder

For those of us who build wooden sailing ships,  the plans come with WL.  Rather than doing any lofting, the WL from the plans determine the lift thickness.

The hollow insides are a requirement from the USN museum. 

[Bob Cleek]

12 hours ago, Jaager said:

For those of us who build wooden sailing ships,  the plans come with WL.  Rather than doing any lofting, the WL from the plans determine the lift thickness.

The hollow insides are a requirement from the USN museum. 

Very true. The poster intends to build a radio controlled model, so he'll have to open up the inside. I think the USN's model standards require hollowed bread and butter hulls because this makes the model much less heavy and they do a fair amount of moving their models around. The USN's ship model "mil specs" also require lifts be in two pieces, one to each side and glued together down the centerline (being cut two at a time as described in my previous post.) I believe this is required because of the propensity of a single plank splitting along the grain at the "pointy ends" of the center cut-out, but I'm not sure I understand exactly why that would be any different than a glue joint. I suppose the glue joint done properly would be stronger than a narrow section of grain alone.

 

If the plans show the waterlines, there's no reason not to use those, but if the body section plans are available without the waterlines superimposed, or if one wanted to set the thickness of their lifts themselves, it's an easy thing to line off your own waterlines on top of the body sections and take off the distances at each body section station for each waterline. 

Edited March 17, 2023 by Bob Cleek