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Author Topic: Mv Cast Bluewhale scratch build  (Read 1108 times)

MvModeller

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Mv Cast Bluewhale scratch build
« on: February 08, 2018, 06:47:33 PM »

Hello there,


Thought id introduce myself and ask a few newbie questions while im at it  :-))


Im 35 from Lancashire, recently moved here from kent. Have always had an interest in Marine modelling, but never acted upon it. Ive been heavily into Model Railways from a young age, so not affraid to use a stanley knife lol


Now, I completely understand your views on my 'going in blind' with a build such as an OBO carrier like MV Cast Blue Whale, however Im really looking forward to the task and skills i will pick up along the way, if it turns out to be an epic fail,  lessons will be learnt and I can say I tried. And you can say "we told you so"  ok2


So, excuse my lack of knowledge.


1. The Hull construction.


I have seen a very impressive model of the Emma Maersk container ship on You Tube, where the modeller shapes the hull with Styropor, chops the hull into sections for the bulkheads, cuts ply bulkheads into the correct shape and sandwiches the sections back together creating the basic shape. Now I understand for a working RC ship the hull needs space for radio gear ect, so the styropor in its hull shape would be in the way.


After this stage he covers the hull in Balsa, a while later a perfect hull finish for a static model.


My question is, could this method be used for a working RC model, or is this something that only a static model would get away with?


I ask this question as I feel planking the hull like you should, seems way above my experience. Obviously.


2. Sealing the Hull


The hull itself would obviously need sealing so that its water tight. What are the best ways of doing this with balsa wood? (If the above question is possible) and what filler is recomended for this type of job.


Many thanks for taking the time to read my questions, the youtube link for the Emma Maersk build is here .... https://youtu.be/8qlNx_6wD8Q


Best regards %%

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ballastanksian

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Re: Mv Cast Bluewhale scratch build
« Reply #1 on: February 08, 2018, 07:57:58 PM »

Welcome to the forum MV! I like your avatar. It's simple but witty  :}

To answer your first question: Using styrofoam/styropor/blue foam etc is a small but interesting area in the family of model hull building. The methods I have seen created by Ron Rees (fellow Mayhemer and article writer for Model Boats) builds many of his models with styrofoam but without the balsa frames.

The hull is shaped externally and then, like a dugout canoe, the interior is removed. Ron uses a home made hot wire cutter with shaped blades from thicker wire bent to allow him to remove square sections of foam making internal cleaning and preparation for fitting RC 'gubbins' much easier.

This is not as difficult as it sounds if you have an eye for form, though you can cut card templates out matching the stations of the frames so you can carve and sand the exterior to the correct form.

For the second question, this was discussed recently on a topic and came down to two main schools of thought.

1. Accepting that the odd dink will occur, an old and loved method is to paint several coats of thinned dope or acrylic varnish onto the bare balsa hull followed by a layer of model aircraft tissue applied like you would GRP using a brush to stipple the dope/varnish onto the tissue. Do a couple of layers and then sand smooth adding a final layer of dope and then clean for priming.

2. GRP. This is not as difficult as it seems but it is messy, smelly and needs some preparation to get the best results. Also, if applying over styrofoam, it will eat this away for a pastime, so either use the Deluxe materials system with acrylic laying up resin 'Ezekote' and their mat, or a similar make from a supplier which will be cheaper if you need more than one packs worth of GR cloth.

With both methods, some practice and having alook in the master class section here will help you immensly. There is a topic on hull planking, Missy D is building the Mady-Jean, where you can see exquisite carpentray going on. Have a good read through all the rooms etc as you finding this forum is the model boating equivalent of Lord thingy finding Pharoah Tut's tomb!


Seriously.
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JimG

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Re: Mv Cast Bluewhale scratch build
« Reply #2 on: February 08, 2018, 08:27:50 PM »



2. GRP. This is not as difficult as it seems but it is messy, smelly and needs some preparation to get the best results. Also, if applying over styrofoam, it will eat this away for a pastime, so either use the Deluxe materials system with acrylic laying up resin 'Ezekote' and their mat, or a similar make from a supplier which will be cheaper if you need more than one packs worth of GR cloth.


If you intend to cover in GRP use epoxy instead of polyester or acrylic resin. It's still a bit messy but the epoxy doesn't have a strong smell and can be used indoors without complaints. Also if using epoxy use glass cloth not chopped strand mat. The mat strands are held together with a resin that dissolves in polyester, epoxy does not do this so the mat will not lay down properly. Epoxy does not dissolve styrofoam so can be used without any previous coating on the foam.

Jim
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MvModeller

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Re: Mv Cast Bluewhale scratch build
« Reply #3 on: February 11, 2018, 09:10:49 PM »

Many thanks for your very detailed advice, all has been noted.
I have yet to purchase the plans for this build, but have been researching a couple of hull build techniques.

I do like the idea of moulding the hull shape like Ron has done with Emma, however I do like the idea of working with wood.


As an experienced Marine Modeller would the following Idea have any issues? That you could foresee?


The hull...


All bulkheads and keel? (Spine) of the ship are cut and formed with plywood.


Instead of planking the ship in the traditional way, infilling the gaps between the bulkheads with either Styrofoam or Balsa Wood cut or sanded to the shape of the bulkheads to form the hull shape.


The Styrofoam infill option would then be planked with Balsa Wood like Rons Emma Maersk. Once set formed and sealed the inside dug out for internal RC gubbins ect?


The Balsa wood Infill option would be cut and sanded to form the same lines as the bulkheads, sealed and painted?


I have yet to learn about how the weight of the ship can affect its ability float. Im guessing its not as easy as thats my hull it will float.. job done.


So.. do you think the above idea is barmy? What issues could I have if any?


Thanks once again for your advice,


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ballastanksian

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Re: Mv Cast Bluewhale scratch build
« Reply #4 on: February 11, 2018, 09:33:53 PM »

If you want to Keep costs down, I would follow his method using polystyrene and evolve your design from that. But I would use blue or pink foam instead which has a denser structure. As Glynn Guest always says in his articles, look for medium grade balsa that is not too soft but can still be  processed by hand. A good supplier should be able to select for you, and if you have a really good model shop, they might have a good selection of balsa.

do you need to go down the  foam infill route with balsa planking route? The balsa will not be much harder than the foam and will, itself, need something to protect it such as already mentioned, i.e, GRP or tissue and dope. So do away with the balsa and coat your foam/ply frames with one of the above methods saving you money and time.

Ron Rees extolls the virtue of using women's tights as the fabric layer. Honest!
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buntzi

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Re: Mv Cast Bluewhale scratch build
« Reply #5 on: February 13, 2018, 07:11:37 AM »

[...]I do like the idea of working with wood[...]
The hull...
All bulkheads and keel? (Spine) of the ship are cut and formed with plywood.
[...]Instead of planking the ship in the traditional way[...]
Sorry, but I have to ask: If you like the ideea of working with wood, why not go for the classic plank on frames method? It is not very different from what you're proposing, is pretty much the same amount of work. You still want to have frames/bulkheads and a keel, so you're already half way there.
There's how I see the process:
Option 1 (your original idea, with foam): Cut plywood keel and bulkheads > fill with foam/balsa> shape foam> plank with balsa> shape, filler, sanding, filler, sanding> use glass matt & resin to reinforce balsa> sanding, filler, sanding> cut foam and bulkheads to make room for rudder and propeller tubes, electronics, batteries and ballast etc.> primer> final paint coat.
Option 2 (what I'm suggesting): Cut plywood keel and bulkheads > plank with balsa / wood stripes> shape, filler, sanding, filler, sanding> use glass mat & resin to reinforce balsa / wood hull> sanding, filler, sanding> primer> final paint coat.
It would be equally messy :D just in a different way (instead of having foam bits and dust everywhere, it would be wood bits and dust). But you will have the advantage of having the space already free for your components and the possibility to plan the shape of the frames inside part according to your needs. Maybe some of the front frames can be bulkheads (to spare you some work) if you don't need the space there, but I would not recommend closed compartments where water can sip in without the possibility of intervention.
Hope it helps your decision.
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MvModeller

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Re: Mv Cast Bluewhale scratch build
« Reply #6 on: February 18, 2018, 02:01:14 PM »

Hello Buntzi... you have a very good point, and i get that. But i cannot help but think planking looks so difficult. And maybe more could go wrong..
Im on the fence at the moment, i think once I obtain the plans i need, A decision will be made.
Im going to have a look at the artical on this ships build that was published in August 2000 Marine Modelling magazine.. maybe go down the same route. Im told it was a card build.


Once again thanks for the info.. all will be considered, hope to get back with an update soon... looking forward to getting into this hobby... have always wanted to.. life just got in the way  :}
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buntzi

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Re: Mv Cast Bluewhale scratch build
« Reply #7 on: February 19, 2018, 06:38:56 AM »

Hi there MV,
I understand your concerns. The Nordkap that I've built was the first try (for this method and many many other things too) for myself also, but it turned out to be much easier than initially thought.
Anyway, good luck with your build.
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MvModeller

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Re: Mv Cast Bluewhale scratch build
« Reply #8 on: March 24, 2018, 03:12:15 PM »

So, Ive managed to get the plans for this build, very exciting looking them over..
Ive thought long and hard about what method of building to use, buntzi,  your advice was bang on the mark.


The actual plans are just for a card model, which has thrown a spanner in the works, (I thought I read for both card and plywood build) but I feel I could probably work from these to create a wooden hull like suggested. (Or a least try) being a novice, this could go wrong.. But... Going to give it a go.




The one question I do have... this model in 220mm wide and 1200 on length, The weight of this model concerns me with regards to the type of wood for this build, would you recommend any particular types?
Im thinking plywood for the structural frame work then Balsa for the planking?
Best Regards
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buntzi

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Re: Mv Cast Bluewhale scratch build
« Reply #9 on: March 26, 2018, 07:57:07 AM »

I'm glad that I could help a little. For such a large vessel, I would suggest either a stronger material than balsa, or some added reinforcements along the hull (I'm sorry, I miss now the english equivalent word for it). I guess even a single reinforcement at water line level should do the part (5x5mm wood stripe maybe?) or two shall add sufficient rigidity to the whole structure until you cover the frame assembly with balsa.
Honestly, I would go for the reinforcement idea rather than stronger wood. Also, 5mm plywood shall be strong enough for the frames, but the keel is the one to watch out for warping trouble.
There is not much difference in developing the plans for plywood instead of card. I wouls say that the main difference is in regard to the thickness of the hull. Card probably consider very less (1mm, if at all) thickness, while with balsa and all the other layers you shall think about 2mm thickness.
Hope it helps.
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MvModeller

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Re: Mv Cast Bluewhale scratch build
« Reply #10 on: May 13, 2018, 09:38:37 PM »

Hi there...


So.. ive started tracing all the bulk heads from the plans i have..
Now bearing in mind the plans are for a card build not a wooden build, The spacing between these bulkheads are 2cm, but there are 52 of them? Would I be correct in saying this amount of ply bulkheads in a build from a plan for Card could be too heavy?


Probably difficult to answer without seeing the plans...
Any advice in this area would be great.


Mv
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MvModeller

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Re: Mv Cast Bluewhale scratch build
« Reply #11 on: May 13, 2018, 10:21:43 PM »

https://www.dropbox.com/s/cmlggicu5qbexsr/20180512_234158.jpg?dl=0

Work done so far, not really any point in this picture, to be honest just testing to make sure you can see an image for future posts...
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dreadnought72

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Re: Mv Cast Bluewhale scratch build
« Reply #12 on: May 13, 2018, 10:38:25 PM »

2cm spacing is unnecessarily close for a standard boxy-type cargo hull.


You say that the hull length is 120cm, beam 22cm? I'd be leaning towards building the whole thing in balsa alone - set the keel on a solid baseboard, with a frame every 5cm to 7.5cm, planking over the frames from the bulkwark downwards in something like 3mm balsa. Plank the lower sides and bottom once the hull's solid and safe to remove from the baseboard. Leave complex areas (stern, bow, bulb) to infill with block balsa and carefully carve later. A skim of glass tissue and resin over the top once it's sanded.


Andy
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MvModeller

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Re: Mv Cast Bluewhale scratch build
« Reply #13 on: May 14, 2018, 05:48:27 PM »

Many thanks for the feedback dreadnought,
The bulkheads at the stern and bow of the ship are measured for the curves to shape the hull, so im guessing the bow and stern will have to remain at 2cm intivals, maybe space the bulkheads at 5cm at the center of the ship to reduce weight?


Sorry for all the questions, The keel.. would you suggest having the keel in Balsa? Or something a little stronger?
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Re: Mv Cast Bluewhale scratch build
« Reply #14 on: May 14, 2018, 09:20:41 PM »

"It depends"  %)


You could cut the keel and frames from (3mm) ply, and then plank in balsa - but you'll hate pinning balsa planks to a ply frame. Trust me: I've done this - I have the callouses. Personally (for a mostly box-shaped hull) I'd lay a 3mm sheet balsa floor where it's shown as flat on the plans, glue on a 6mm wide & everso straight keel (balsa) onto your building board, add 6mm balsa frames onto this (keep 'em perfectly perpendicular to the keel), and plank away with 3mm strips, starting at the top-edge at the decks and work down-the-way. Maybe 2mm or less would work with a final glassfibre skin. The final balsa/laminate hull you construct is a monocoque: a totally sturdy 'U' shaped structure whose strength doesn't rely merely on 'keel and frames' but on edge-glued planking and glassfibre skin.


You don't need to over-think this - check out some of the plank-on-frame builds.


Really difficult areas - bow bulbs, etc., where planking doesn't work - build up balsa blocks and carve/sand to shape.


Andy
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Re: Mv Cast Bluewhale scratch build
« Reply #15 on: May 14, 2018, 09:40:16 PM »

Example:





Planking for the Dreadnought in 3mm balsa over 3mm play. The very bow (bottom of the picture) is block balsa carved to shape. (I've marked in dayglo pens the plating overlying this hull form, so all the wood is finally hidden).
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ballastanksian

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Re: Mv Cast Bluewhale scratch build
« Reply #16 on: May 14, 2018, 10:07:37 PM »


The key is preparation. Also, make a maquette to test out some plank on frame ideas you have and fellow mayhemers have suggested. It need be only two oblong bulkheads with rounded corners on an oblong base on which you can practice cutting and fitting planks, then put these ideas into your build. Planking has the aura of being really complex, but it is just a case of making sure your frames are true, the edges are properly bevelled, and that the base board and keel are also true. BUT. If you are happy to build a composite with foam and wood then do so. If it turns out to be a real headache then you have learnt for the future, if you succeed, then you will be able to use your ideas and tips for future builds.


As Dreadnought says, do read some of the other build logs especially Missy D's, or Dreadnought's, or raflaunches, or Geoff,s amongst many others and you will see much knowledge of working with wood in our own nautical field.
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buntzi

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Re: Mv Cast Bluewhale scratch build
« Reply #17 on: May 17, 2018, 07:42:20 AM »

[...]Now bearing in mind the plans are for a card build not a wooden build, The spacing between these bulkheads are 2cm, but there are 52 of them? Would I be correct in saying this amount of ply bulkheads in a build from a plan for Card could be too heavy?[...]
Cardboard is not nearly as strong as plywood. My opinion is that you can safely skip two frames (thus getting about 60 mm between frames). If the section is quite square, you can skip even more, as long as you provide a little bit of strengthening in the way of (let's say) 5x5 mm strips. You can also keep some more frames near the bow or the stern, but as @dreadnought said before, it's much easier to shape balsa blocks for the very sharply curved parts than to bend balsa sheets to follow the frames.
As for the weight of the model, I wouldn't be very concerned about this. At that size the model will have to weigh about 7-8 kg (I guess) to sit properly to the waterline, so I guess that not the weight is the one to worry about, but the sheer amount of work that you have to put in cutting and sanding all those 52 frames...
Hope it helps and good luck with your build!
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