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.

Thanks Bruce. I purchased the kit on the eBay under $100, but the parts were missing! I had to buy CNC machine from china which costs $80, studied how to use it, and made the wheels from plastic panels.

Hello, Before starting reading this, sorry about my poor English skill. I'm a wooden ship modeller which is considered most rare hobbiest in South Korea. Because of super thin community in SK, I had a lot of help from this forum when I built my ships. Thank you. I began with the Artesania endeavour longboat, and the most recent ship I completed was the Artesania King of the Mississippi. Currently I'm building a 'la recouvrance' from the Soclaine. The reason I decided to join this foreign community is that I want to share my technic regarding unventable tungsten reinforced mast to everyone. I searched several times related with my technic, but there were no topics related with it. I want to open the technic to everyone and receive feedbacks from worldwide modellers to improve it. I'm a newbie modeller, so my most activities will be reading or searching topics, but I hope you people enjoy my pictures when I finish each ships. Thank you for reading, and happy new lunar year. masa