RC India

Hello everyone
I could not find any topic relating to basics of boat building so, I took the initiative...

In this topic, I would like advice from boat builders about basics of scratch building boats and ships whith thermocol, foam boards, fiberglass and all possible materials...

Please contribute and share your knowledg experts... :bow:

have you finished the Airbus A320 ?

Out of coro... term exams going on too... finished Studying but no coro to work with...probably will go out after this month end to fetch some coro...
Do u want to buy it? :P

Please don't deviate the topic

Have you finished AVI Spad? There is a reason why Saikat and I ask

All lying w/o electronics in my cupboards

Hey Great Idea sirji.

We do require some serious knowledge article on Boats design, construction and Hardware.

Will be a great post to see all experts like SB sir, VC, Sunk, Roopkrishna, sharing their knoweledge here (Sorry I missed many in that list  ;D)

 :thumbsup: :thumbsup:

Buddy,

this is very nice idea. We should keep it segment wise. i.e Period ships,Modern speed boats,Yacht or any other.

Hello,
Here are some common types of hulls use in model boats.
1)   Vee Hull (Mono Hull): - As name suggest shape of hull is like V shaped. There are different types of V hull commonly used Shallow V and Deep V. Works good in rough water handles good at turning but are tricky to balance. Most deep V is powered by single engine/motor but some shallow V boats are twin powered. Problem with twin in deep V is during turns one of the propellers gets more load than other. Power distribution a change drastically and there is fear of flipping over during tight turns. Mono hull or Deep V is good for some high speed tight turn action.

2)   Tunnel Hull (catamaran and trimaran): - These are boats with two or more hull connected with each other laterally. The gap between two hulls creates air pressure while in fast motion which in turns lift the hull to reduce the drag from water. These are very fast hulls usually powered by two engines/motor running contra rotating propellers. We can use single or double engine setup on this hull. Wide hulls allow us to place more equipment than any other type hull. Usually tunnel hull are dragsters they can attend higher speed as there is less drag from water. 


3)   Outriggers: - These are speed demons requires expert level of handling. Specially made for oval races.  They usually go in clockwise oval course. In outrigger two sponsons attached to man hull which is flat bottom. On left sponson there is stabilizer fin which keeps it from flipping over during turn. Outriggers are very sensitive than other hull types if you pull throttle very hard from rest position it will flip on spot or if boat is in speed and you cut the throttle instantly it will dig in water that may spoil your electronics.

4)   Flat bottom (usually Airboat): - These hulls as name suggest have flat bottom. These kinds of hull are used with airplane propeller with airplane engine/motor. These are pushed by air forcing backwards which is directed by big rudders attached after propeller usually pusher setup. No moving part from boat touches water except hull. These hull lacks maneuverability as they need to be in Continuous power to move and change direction.

Any update/correction/comment are welcome

Thanks for contributing...
Now please contribute info on the segments like Gajjark said...
Info can be categorized on the basis of skill required to build and ease of use of materials

I am not sure about others, but I prefer Balsa. There is nothing like a balsa Except for cost but now a days Carbon fiber is most expensive material to construct models and the latest and strongest one.

Advantages of Balsa:-
1) Most important thing in any plan is getting the right pieces. Cuts smooth just with paper cutter or thermocol cutter readily available in almost every stationary shop. Bit difficult in cross grains but comparatively easy with other materials.
2) Availability, now not that easily available in any store but you can get it at almost all hobby stores. As compared to other material it is uniform all over you get it form Chennai or Mumbai or Delhi you get same balsa all around except little cheap brown balsa don’t know the exact name.
3) What can be worse than a hobby which makes you sick? Balsa is the safest for very simple reason... because it’s natural. Yes, saw dust can cause issue but not is much extend and but using mask while sanding is advised.
Disadvantages:-
1)   Not that strong – If we intend to use balsa we cannot use models made of only balsa. Your model will lack strength plus it will be heavy on your pockets as well. Parts like bulkhead and Keel of a model needs to be strong. They are foundation of any model. Slight bend on keel and boat will not go straight (Thought of using it against prop walk  :headscratch: :giggle:) . A coat of fiber glass will give rock solid strength.
2)   Life of balsa especially for boat is less. Wet balsa can become very soft and can spoil your paint job. In boats mostly in shallow bottom hulls water will leak from the shaft casing if not secured properly. Best way to avoid this is by painting the inner part of hull to avoid any contact with water.

These are all my view. Any update/correction/comments are always welcome

Hey topalle, I am just putting my views and understanding. There are others with far better knowledge on construction of hull. It would be great to have them here and share their views.

Amit

Sunboard, anytime.

Easy to cut, shape, bend, glue. Can be strengthened and made waterproof with Resin.

Disadvantage? Heavy compared to Balsa

+ 1 Rai Saheb! Hands down winner over Balsa as far as boats are concerned.

Should be. Had never heard of the stuff till you sent me some for my first boat build :D ;)

Sunboard = coro?

Then I don't need to look of another material when I have loads of it in my backyard

Sunboard ≠ Coro  ;D

Sunboard = Foam board. (probably PVC foam)                                                                                                                                                    

Where can we expect to find it?

Sunboard = conpressed PVC foam

Corro = Sunpack

Depron = Foamboard

Depron without paper backing = biofoam ;D

Sent from my GT-S7562 using Tapatalk 2

Was confused between sunboard and sun pack...
Which shops sell it?

With respect, for scale model I think balsa will be preferred,   finish of balsa and the curves/shape we can model them is unmatched.

Amit, with my limited knowledge, I don't think Balsa would have made a significant difference to the curves of this boat. By the way, she is a scale model.

A reputed company like Dumas is shifting to compressed PVC foam from Balsa for its Boat kits:

http://www.rcottawa.com/forum/index.php?topic=8439.0

It is not only the material that counts, it is also the technique involved. Here is the classic way of plank on strip building. Perfect curves after sanding!

http://www.building-model-boats.com/planking-rc-boat-hull.html

http://www.pt-boat.com/Hull2/Hull2.html

However, to be perfectly HONEST - if Balsa and Foam Board were available at the same price, I wonder what I would use for my builds? ???

VC sir,if you have limited knowledge then I have not even started studying. I know about boats but you are an expert. First of all I have never used sunboard, so no experience with sunboard and I was having wrong picture(like cardboard made of pvc) of sunboard. And the model it is awesome, I could even see some inward curves. Those are difficult even with balsa. Is sunboard available in hobby stores or we can get it from local market? Can I use it to make big model, does it have strength to take nitro or gas engine? Does it require fiber glass coat or we can get the finish directly with primer and paint? Cost, which is economical balsa or sunboard?

Too much question but answers will be really helpful.

Send me your address and I would be glad to send you a small sample of foam board. You can take this sample and go scouting for it in Mysore. You should get it easily. Ask a cobbler (Mochi) show him the sample and he should be able to guide you. They use it, sometimes for making insoles. Or else, you should draw some leads from photo framers.

Economy?

Balsa : 750mm X 100 mm X 3 mm = Rs.150/- approx.

Foam Board : 1000 mm X 1000 mm X 3 mm  = Rs. 200/- approx.

 ;)

Strength:

The largest that I have built with foam is the RAF FIRE Boat. If your bulkheads and formers are spaced closely, there is no reason that you can't build bigger with PVC Foam. The inner skeleton has to be built strong.

I am seriously considering building the 950 mm Speedboat Aastha out of PVC foam. I can save a lot of cheap Balsa / Japonica. Balsa sands better and dents and dings can be made to disappear with a smooth sand. PVC Foam (the dust, you are right, is unhealthy) needs a coat of automotive putty, followed by sanding for a REALLY smooth finish. However, after that is done it is very solid!

Forget fibreglass and all the hassles involved - get hold of Wembleys Quickfix. Dilute that with 50% thinner and brush it on. Wait for the first coat to dry hard and then apply a second layer. Now sand it smooth with 150 and then 250 grade emery paper - wet/dry (black paper). Voila! Rock solid.

Thanks sir, that is really helpful. I have planned catamaran with gas engine. Ordered drive hardware ant will order engine in next cc cycle. It would be 42" boat. I had planned with balsa which would be around 6000 - 7000 rs. But now I will first try sunboard.

Thanks for all the information. Please keep it coming.

Will send you the samples tomorrow.

Sir can you be kind enou to send me a small peice for a sample to go about shops searching for it?
Even I want to get into boats... will start with a tugboat

topalle,
 I ll send the same peice once I get it from VC sir. Send me PM with your address.

Uh Oh! Now I have send Amit a bigger sample! ;D

Good. Thread. VC some more posts from your experience? Worthy of sticky

Now please discuss about material construction techniques step by step like building the hull,waterproofing, adding electronics, deck ,detailing, etc

Topalle, trying to do something like that here:

http://www.rcindia.org/boats/aastha-scratchbuilt-speedboat/

Here are some pics for reference. It is a simple way to construct any boat or ship structure.

1) final the design
2) calculate the size
3) final the material to be used
4) take design on butter paper or get ito done on autocad
5) if doing manual cutting then trace it on material
6) if on cnc or laser cut then it will give you a perfect cut 1 to 1000 pcs and more
7) fix it on keel
8) cover it with sheet or strip

I think will be able to upload many thing from my current project. But my first and for most preference is balsa. No matter what is the cost