Making unventable tungsten reinforced masts

[modeller_masa]

I'm a newbie modeller, so please consider this article as a beginner's rough idea.

1. Problem

Wood is weak. According to the Young's modulus of elasticity, most wood sticks are vendable 10 times easier than copper or brass rods. While an elasticity of birch wood which is commonly used for mast is just about 15 GPa while the other commonly used woods spread over 6~12 GPa.

(Cutty sark, National Research Institute of Maritime Cultural Heritage, South Korea)

 

Because of the weakness, thin masts such as under 5mm are easily vendable or breakable. The reason of the defects are various like a rigging tension, humidity, temperature, and sun light. It is a critical defect for wooden ship model because it makes the model really bad. Most wooden model ship's life time is longer than decades, and it is very difficult to keep wood condition stable for that long time.Therefore, we need to do something on wooden masts to keep it best.
 

 

2. Concept

If wood is weak, then we can use or add another materials to overcome within a boundary of 'wooden model ship'.

 

(2-1) Metal mast
Easiest way to make an unventable mast. Only for painted ships such as HMS Victory. Also, it costs a lot for beginners. It requires metal lathe which costs more than $1,000.

(2-2) Metal cored mast
For non-painted masts, we can insert very firm metal core into a mast like a pencil. A benefit of this method is is that you can make your own mast regardless the wood's firmness. I'm making Padauk surface + tungsten core masts. You can use any kind of beautiful woods even if it is a Balsa. Even if a grain is 90 degrees angled which is the weakest situation, the metal core will endure the pressure.

 

 

3. materials

 

(1) Young's modulus of elasticity

https://en.wikipedia.org/wiki/Young's_modulus

 

According to this chart, we can easily find suitable materials for the metal core reinforcement.

 

- Acryl, PVC plastic : 2~3
- Most common woods : 6~12
- Birch : 15
- Aluminium : 70
- Brass, copper : 100~120
- Steel : 200~250
- Tungsten (Carbide) : 400~650
- Diamond or carbon nano tubes : 1200, 1000+

 

I've tested some materials on the list and figured out several cheap and useful metal rods.

 

(2) Brass or copper rods
Some people might say that brass wire is weak, but it is 10 times stronger than pine wood! Of course, thin brass wire is useless to keep mast's straightness, so you should use more than 2mm of brass rods.

 

(3) steel rods
There are many types of iron rods, but the best one is S45C carbon steel which is commonly used in CNC machines. Also, it is relatively easy to cut by Proxxon metal cutter. Highly recommended, but difficult to buy under 3mm rod. Piano wire or stainless rods are less firmer than it and very difficult to cut. Not recommended, but easy to find and buy between 1~3mm rods.

 

(4) Tungsten rods
Here is the strongest material I've ever seen. Only a 1.00mm tungsten rod is firmer than 2.5mm brass rod! I'm not a Saudi's prince, so I apologize for not testing diamond rod.

 

Check youtube how much time takes to cut tungsten rod. Only diamond grinder can cut it after several minutes of grinding. Fortunately, you can break 1.00mm and 1.60mm tungsten rod by two pliers. You cannot break tungsten rod over 2.00mm.

 

It is a little bit tricky to buy tungsten rods. Find 'tungsten electrodes'. It's length is only 150mm, and the price starts from $4 (1.00mm, ten rods), but I guarantee that this is the best material to make unventable SLIM mast.

 

Oh, I'm pretty sure that you don't want to be the Wolverine. Don't buy RADIOACTIVE tungsten electrods which include thorium (WT series). Buy WL (Lanthanumized), WP (Pure tungsten), or the other electrods.
 

 

4. Requirements

 

(1) Wood lathe
It is not impossible to insert tungsten rods into polished masts from a kit, but you may need drill station with super long and thin drill bit which doesn't exist. (Imagine a 1mm thickness and 400mm long argur drill bit.) Therefore, if a mast's length is too long, making a wood stick from lathe is more reasonable way in my opinion.

 

(2) Loctite 401 super glue or epoxy glue
There is a many way to bond metal with wood, and I would say that super glue and epoxy glue are the strongest way to attach them. Also, the 401 glue is much faster than epoxy.
 

5. Plan

There are many ways to make wood sticks. But in this case, we need to put tungsten rod into a wood stick and hide it.

 

(1) Determine which mast you will change.

It will be perfect if you change all the wood masts to metal masts, but it consumes lots of time and money. Also, you don't need metal core for heavy duty masts such as over 10mm diameter. Personally, I recommend you to reinforce masts between 3mm to 6mm. Less than 3mm is too thin to install metal core and not effective. More than 6mm wood stick is strong enough to endure years of pressures. In addition, masts for sails may not need this kind of reinforcement because of weak pressure.

 

(2) Firmness calculation
The firmness of wood stick depends on its grain and thickness. Because of anisotropic grain, wood's modulus of elasticity decreases significantly by pressure from the weakest side. Fortunately, sufficient metal core will help to endure the pressure and keep straightness. From this simple formula, you can estimate how many thickness of metal core will be.

 

Target firmness = Wood stick (10mm diameter) = 1 (Wood's firmness) x π (3.1415..) x 10^2 = 314.15 (100%)
Current = Wood stick (3mm diameter) = 1 x π x 3^2 = 28.27 (approx. 9%)
Brass rod 1mm core = 1 x π x (3^2 - 1^2) + 10 (Brass = 10 times of wood) x π x 1^2 = 56.54 (approx. 18%)
Tungsten electrod 1mm core = 1 x π x (3^2 - 1^2) + 60 (Te = 60 times of wood) x π x 1^2 = 213.62 (approx. 68%)

 

(Common wood = 1, Birch wood = 1.5, Iron wood = 2,
Brass = 10, copper = 12, Piano wire = 20, S45C steel = 25, Tungsten = 60)

 

In this case (3mm wood stick), you can get 68% of firmness of 10mm wood stick when you insert a 1mm tungsten rod. It is 7.5 times harder than native wood stick and equivalent to 8mm pure wood stick!

 

(3) Limitation
- Do not use brass tube or metal tube series. It is weaker than wood.
- I don't recommend to insert metal core for less than 3mm mast. Because of the smallest diameter of tungsten rod is 1.00mm, 3mm masts will have only 1mm wood skin. Less than 1mm skin is very fragile and unstable. Also, some woods have lots of holes on the surface. They may consume and expose super glue from inner core, and make dark spots.
 

 

6. Making metal cored masts

I skip this section because of poor English skill. (I want to write so many lessons from my experiences!) I believe you expert modellers will find much better ways.
 

 

7. FYI

(1) I don't know how long the metal cored wood stick will keep its shape. I hope it lasts longer than centuries. 
(2) I don't guarantee your health if you use cheap radioactive tungsten rod. (Finger crossed)

 

 

 

 

(Two Padauk 8mm masts reinforced by S45C 3mm steel rods and one Padauk 4mm mast reinforced by WL15 1.00mm tungsten rod, on working)

 

 

 

I hope you enjoyed my idea. If you have any opinions or thoughts to improve my idea, please don't hesitate to leave a reply.

 

[druxey]

It's an interesting concept, masa. However, would this self-destruct in time as the coefficients of expansion/contraction of metal and wood are dissimilar, plus the effects of varying humidity on wood?

[modeller_masa]

9 hours ago, druxey said:

It's an interesting concept, masa. However, would this self-destruct in time as the coefficients of expansion/contraction of metal and wood are dissimilar, plus the effects of varying humidity on wood?

I agree that. That's what I'm worrying the most because I don't have any clues to measure the destructive effect. Hm... I remember that I saw some books regarding conservation of wooden cultural properties at a Maritime library. I'll check the books and add more theoretical evidences as much as possible. It will be more rational than a test I planned at first. (I planned to freeze and melt metal cored masts several times using refrigerator.)

 

By the way, we already use lots of metal parts such as rings to decorate masts or to fix horizontal masts. I guess that 'inner' metal parts are less destructive than 'outer' parts because metal is more stable than wood. 

 

There may be a reason that nobody used metal cored wood sticks in hundreds years of wooden model history. It seems very interesting, and I want to figure out the reason if your worry is correct.

Edited January 27, 2020 by modeller_masa

[the learner]

fascinating idea though perhaps it could be applied to plastic modeling where mast and spars have more of a tendency  to bend from pressure of the rigging or  perhaps an epoxy glue would prohibit expansion/contraction of metal and wood  when applied to adhere the metal and wood together.

 

 

[modeller_masa]

1 hour ago, the learner said:

fascinating idea though perhaps it could be applied to plastic modeling where mast and spars have more of a tendency  to bend from pressure of the rigging or  perhaps an epoxy glue would prohibit expansion/contraction of metal and wood  when applied to adhere the metal and wood together.

 

 

Good brainstroming. I think tungsten rod with epoxy coated tank canon will be good. I like your creativity.

[the learner]

let us know how it works!

[Bob Cleek]

Note that the US Navy Naval Sea Systems Command which includes the Navy's Curator for Ship Models division specifies in their requirements for model contracts that all "masts, antenna masts, yardarms (sic!), boom, etc. less than 3/16" diameter shall be metal."

 

See: Specifications for Building Model Ships at https://www.navsea.navy.mil/Home/Warfare-Centers/NSWC-Carderock/Resources/Curator-of-Navy-Ship-Models/Specifications-for-Building-Exhibition-Ship-Models/

 

I believe that in large measure the same specifications have been adopted by the Smithsonian Institution and Mystic Seaport and that they are generally recognized by professional museum curators as defining "museum quality" in so far as that term can be defined. I follow these specifications to the extent possible. Obviously, some requirements are difficult to meet these days, e.g. linen rigging line. They recognize that new materials come along all the time, but caution that they are often of unproven archival quality. I take that caution seriously. What's the point of spending the time it takes to build a good model, only to have it fall apart in a few decades. 

 

See also Mystic's Ship Model Classification Guidelines developed by Howard I. Chapelle: http://www.shipmodel.com/pdfs/ship-model-classification-guidelines-1980.pdf

 

Edited January 28, 2020 by Bob Cleek

[modeller_masa]

14 hours ago, the learner said:

let us know how it works!

In the next post, I'll upload the cheapest and easiest way to make a wood stick. I'm tired of turning lathe.

 

(updated) Oops. I found significant issue from the method. I give up to post it.

By the way, you can find tons of ways to make dowel=mast from Youtube.

Edited January 29, 2020 by modeller_masa

[modeller_masa]

9 hours ago, Bob Cleek said:

Note that the US Navy Naval Sea Systems Command which includes the Navy's Curator for Ship Models division specifies in their requirements for model contracts that all "masts, antenna masts, yardarms (sic!), boom, etc. less than 3/16" diameter shall be metal."

 

See: Specifications for Building Model Ships at https://www.navsea.navy.mil/Home/Warfare-Centers/NSWC-Carderock/Resources/Curator-of-Navy-Ship-Models/Specifications-for-Building-Exhibition-Ship-Models/

 

I believe that in large measure the same specifications have been adopted by the Smithsonian Institution and Mystic Seaport and that they are generally recognized by professional museum curators as defining "museum quality" in so far as that term can be defined. I follow these specifications to the extent possible. Obviously, some requirements are difficult to meet these days, e.g. linen rigging line. They recognize that new materials come along all the time, but caution that they are often of unproven archival quality. I take that caution seriously. What's the point of spending the time it takes to build a good model, only to have it fall apart in a few decades. 

 

See also Mystic's Ship Model Classification Guidelines developed by Howard I. Chapelle: http://www.shipmodel.com/pdfs/ship-model-classification-guidelines-1980.pdf

 

Thank you for good information! 'Museum quality guidelines' sounds extremely beautiful. Never heard about it. It will be an awesome guideline for SK modellers when I translate it to Korean.

 

I think a few decades of life time is enough reason to build model ships. Like our(hm! actually your) ancestors made same wooden model ship hundreds years ago and we refer their works when we build, our sons and grand sons will look up our works.

Edited January 29, 2020 by modeller_masa

[wefalck]

One should note that museums normally commission models only at 1:48 or 1:96 (or 1:50 or 1:100 for most of the world) scale. At smaller scales the materials requirements are often difficult to meet.

 

On the practical side, I think when mast and spars of wood are so thin that their stability is of concern, it would be difficult to give them a metal core. I would be better to make them from metal right away.

[modeller_masa]

On 1/30/2020 at 5:42 PM, wefalck said:

One should note that museums normally commission models only at 1:48 or 1:96 (or 1:50 or 1:100 for most of the world) scale. At smaller scales the materials requirements are often difficult to meet.

 

On the practical side, I think when mast and spars of wood are so thin that their stability is of concern, it would be difficult to give them a metal core. I would be better to make them from metal right away.

Thank you for the information. I thought there were no favorite scales.

 

After I translated the museum guideline, I realized that my goal is not making a realistic model, but a beautiful, gorgeous, and looking good model. I bought some serious books about wood preservation, and will dig on the metal-wood gluing, but my priority interest is slightly different from your interests like wood grains and non-painting surfaces. :-) I wish people share their knowhows in various perspectives.

[Bob Cleek]

Whatever one builds, it's important that it be built to last if the work is to endure. Building a good model, or anything else for that matter, takes a considerable amount of time. It all depends upon how much you value your time. We would have nothing of the great works of art from ages past if they hadn't been made to last as long as they have. 

[wefalck]

Luckily, not all modern artists paid attention to this ... 😏

 

[jud]

As metal and wood have different expansion rates during heat changes and the fact that metal is stable in humidity changes but wood is not, I would use a flexible adhesive to allow for that movement.  Might even be better to use a loose but close fit to allow for unrestricted reactions to the environment and use no adhesive. Even silicone dries out over time.

 

[modeller_masa]

5 hours ago, jud said:

As metal and wood have different expansion rates during heat changes and the fact that metal is stable in humidity changes but wood is not, I would use a flexible adhesive to allow for that movement.  Might even be better to use a loose but close fit to allow for unrestricted reactions to the environment and use no adhesive. Even silicone dries out over time.

 

You give me a lot of inspirations. I may not use or use only piece of epoxy resin to hold metal stick in wood. Also, some gaps what you implied may increase lifetime significantly longer than filling CA glue. I have made some furnitures like tables, so I found similarities from what you said and technics to extend durability of furniture.

Edited February 1, 2020 by modeller_masa

[modeller_masa]

10 hours ago, Bob Cleek said:

Whatever one builds, it's important that it be built to last if the work is to endure. Building a good model, or anything else for that matter, takes a considerable amount of time. It all depends upon how much you value your time. We would have nothing of the great works of art from ages past if they hadn't been made to last as long as they have. 

You're right. I didn't want to underestimate other people's value and efforts.

 

My goal is keeping what I made in a good shape until I get soil in my eyes. It may be a reason I felt kind of uncomfortable when I read museum guidelines. Between creativity and realistic limits, my purpose tends to be more adventurous, but I don't think my idea will not change in the future. Maybe more experiences will give me a higher viewpoint.

[modeller_masa]

10 hours ago, wefalck said:

Luckily, not all modern artists paid attention to this ... 😏

 

I'm an engineer. It is very difficult to understand art for me. I choose wooden model ship because of beautility like an airplane. I believe that good engineers make things better without doing too obvious.

[wefalck]

Quite frankly, I think this an artificial problem. If mast and spars are big enough to practically insert a wire, there will not be a stability problem, if a suitable species of wood has been selected. After all, we have century-old models that don‘t have problem. When wood becomes a problem at small scales, it is better, to make masts and spars from metal.

 

We have to also remember, that the standing rigging does not have to be as taught as a violin string. So the loads on masts are quite limited.

 

Against the museum recommendations I made masts from steel rod. Steel is much stiffer than brass, hence it is easier to turn on the lathe. Even with a fixed or travelling steady turning long lengths of brass rod can be a pain.

[modeller_masa]

On 2/1/2020 at 6:23 PM, wefalck said:

Quite frankly, I think this an artificial problem. If mast and spars are big enough to practically insert a wire, there will not be a stability problem, if a suitable species of wood has been selected. After all, we have century-old models that don‘t have problem. When wood becomes a problem at small scales, it is better, to make masts and spars from metal.

 

We have to also remember, that the standing rigging does not have to be as taught as a violin string. So the loads on masts are quite limited.

 

Against the museum recommendations I made masts from steel rod. Steel is much stiffer than brass, hence it is easier to turn on the lathe. Even with a fixed or travelling steady turning long lengths of brass rod can be a pain.

I made this method when I tried to make a mast with 'weak woods' such as padauk. Also, my padauk wood's grain was so bad for making wood stick. After many trials and errors, I choose to keep the padauk rather than use very common birch wood stick because of its beautiful color.

 

People consume wood pretty much quickly. I know we cannot buy 'real Mahogany' which used widely 50 years ago. Because of too much demands on mahogany and danger of extinction, lumbering of it is strictly banned by nations' laws. After that, people began to find another 'mahogany', and merchants are selling fake mahoganys like an indonesian mahogany. In addition, it is already difficult to find Campo woods from Australia after the big wildfire.  Therefore, I would say that wood market has 'trend' by consumption rate. I think there are no guarantee we can buy same wood in the near future. (Of course, birch and walnut will be long enough while pine wood is encountering threat of critical vermin issue.)

 

Furthermore, I want to use various woods regardless tensile strength. Padauk is one of an alternatives of mahogany, and I want to use the color because of the similarity.

 

In conclusion, I want to use any kind of woods. I have a plan of very pinky ship with fancy sail for a little girl. Someone may think wood stain is enough, but making a new way is more funny when everybody say no.

 

 

By the way, it is shame that a national museum in my country doesn't fix the cutty sark.  I think a creator of the ship might do a mistake on rigging. I have more pictures of broken ships in the museum, but I won't upload them due to a same reason.

 

(Added) Thanks to the modern science, we have various kind of steels. Some steel offers better chemical durability. I think anything is ok while the model looks like a wooden made ship.

Edited February 2, 2020 by modeller_masa

[wefalck]

Masts were usually made from pine or fir, coming in Europe from Scandinavia or Russia, but also from domestic forests tended for the purpose, e.g. in France. In North America also pine and fir were used. Mahagony was not used for masts because of its price and also its weight. Pine and fir were also available in long straight lengths and is quite elastic. I don't know what wood species were used in Asia.

 

For models commonly used wood species for masts and spars are pine, beech and ramin. For small yards or in small models for masts and yards also boxwood is used.

 

Mahagony and walnut are too dark for masts in most cases.