The plan seems to indicate weight in the keel, which is where you will need it. I suggest you put the model in your bath add the steel and see how the model floats. All the keel and an inch or so of the hull should be submerged with the weight battery and servos resting in the hull. Add or remove weight to get about right. I would cut a slot in the keel to add the weight as low as possible. The plan seems to suggest this. Seal temporarily and recheck for correct waterline. You could use cling film to seal whilst checking. When happy make good the keel and fit the servos etc and check again before fixing the deck.
The Sea Commander and others from the 1960s all seem to lack any real waterline. Primarily they were designed to race round the sailing waters whilst runing a IC engine and were not normally static the water unlike today. We have several in our club and I have attached a few pics. The Tarpon was a similar model and the waterline is shown on the example. Two shots of my Sea Queen at rest and at low speed. The propshaft adjustment from the original design is minimal, really just lowering the angle to allow the motor to sit lower whilst allowing the prop to clear the hull. On all my models I fit the shaft in a slot in the keel and make good with Car Body filler (Plastic Padding). This avoids the possibility of twisting or bending the shaft when fitting in a tight slot. Merry Christmas and I hope Santa brings you all you desire.
ChrisF I have now floated the boat in the bath tub and measured the top edge of both the front and rear down to the water, back in the workshop I put some masking tape from the waterline mark from front to rear keeping the tape as straight as possible, it is not a million mile away from the Keel less than 2 degrees difference. so the prop will stay where it is. I have also now rubbed one side of the hull down and masked it to the water line and resprayed the top half white, the lower part of the hull will be resprayed black, the waterline line will be put on this. I will then repeat on the other side. I hope this will be correct.
Doug makes a good point about the prop shaft angle with regards to the waterline. Having said that I reckon once on the plane the keel/bottom of the hull will be fairly parallel to the surface of the water so using the keel as reference in this type of boat is fine. Also if you start changing the angle you might have a larger hole in the hull which you have avoided so far! In addition you might have problems with mounting the motor lower down. Chris
Doug, Richard hereit is me that has the digital angle, I got it from a company called Rutland's here in the uk, www.rutlands.co.uk/, Thanks for the info about the water line, looks like I am going to have to use the bathroom bath again as I do not have the waterline marked as I have been experimenting with batteries and their position, the way I see it although I have arrived at a decision using a 56mm prop at the present angle, how do I decide the correct waterline at rest?
Hi Chris, Hi Mark, "the flatter the better" is absolutely right to get more forward thrust and less forward pitch which pushes the bow down. My concern is using the keel as the datum line! Is the keel line parallel with the actual waterline when the boat is at rest? I doubt it, maybe - maybe not. I try to measure against the waterline in order to obtain the maximum forward thrust from a standing start. Chris: I am also very interested to know where you got the digital angle device. I have something similar but it's for building fitted cupboards and such and much too big for model stuff🤔 Merry Christmas all, Doug 😎
Andy The original model was produced in the early 1960s when IC engines were the norm and scale and RC for sailing models were in their early development stages. Supplies were limited and we made do with whatever was available. The plans were typically sheet on frame, probably plywood from an old tea chest and cascamite resin glue ( it was water proof and slow setting). The designer would suggest suitable wood to use but many chose to use what they could acquire and as a result the finished models often finished up heavy or very heavy. Coupled with the large IC engine and flywheel and large heavy RC escarpments and big drycell batteries, it is not surprising that the hulls sat well in the water. To the modellers of the period the waterline really didn't matter as we were after speed, control and endurance. This may explain why the early plans did not show a waterline, as in my experience the draught varied greatly between models. Today we have scale plans and supplies that allow us to build true replicas and all the important detail is a must for a true scale model. Personally as an ex flyer I try and build lite, bricks tend to fall or sink, and my Sea Queen rides high in the water with a slight bow up. A 42xx brushless and LiPo add little weight and I have two 8oz lumps of lead in the stern section to achieve this. If it looks right, sails well and you are happy, then enjoy your model.
I'm afraid my project for the 'lesser known dreadnought' has foundered. Plans from Greenwich have become just too expensive at a net sixty or so quid and photos seem to be virtually non existent other than from long distance. I have acquired some drawings of the 1906 HMS Dreadnought, and have started on her as a waterline model. Any photos welcome!! Attached current state of play.
Your keel shape is a bit longer but very similar Here is some info I have gleaned. Full scale 8 Metre boats - meaning 8 metres at the waterline - go back to around 1907 and they proved extremely popular with around 140 being built around Europe during the first seven years alone. It was a time of very rapid boat development and equally rapid evolution of class rules. At one stage 'Metre Boats' were allowed one foot of beam for every metre of waterline length, a possibly unique combination of metric and imperial in an International Rule. Current 8M boats derive from a model obtained 5-10 years ago by Robin Edgar and Alan Woodroffe of the Southwater Dabblers MBC who thought it was based on a J-Class. However, it was later found that what they had was a model of a Fife 8 Metre instead. In any event, the boat remained of great interest because the hull shape and relatively low draught makes it an excellent choice for shallow waters and especially for ponds with bad weed. They used the model to create some 50+ hulls. Can you tell me more about your mini 12
Hi there, a good looking boat, well done. I also have an Imara which I am currently outfitting the motors (Caldercraft CEM 900T) and electrics, but need advice on the amount of ballast required to get it the correct waterline What was the total weight of the ballast you used? Many Thanks..........Richard
I am also attempting to replicate the excellent miniature Bassett Lowke waterline models to help fill in existing collections and maybe start new ones for others. I have been working so far with Honduras Mahogany and aircraft plywood supplemented with brass fitments. I am doing Olympic and Titanic so far but I am not satisfied yet.
I tried a few different grades of oil and found that if the inside end of the prop tube is close to or below the waterline then some water always seemed to enter the boat, as well as leaving an oil slick in the lake. You also need an oiler tube. Light grade marine grease - whilst offering some friction initially soon eases off on the friction (via a quick run-in), whilst offering a good seal. I have ships, patrol boats and submarines and they all have marine grease. I re-grease the prop tubes/shafts once a year for the frequently used models and others once every few years. I also tried Lithium grease, but it always remains sticky and so does the friction load. In most cases this is great grease except for prop shafts. Choose what ever you are happy with.
Truly captures the look of the real model. The detail is very good and it is a credit to Paul that the model actually sails with all the cabin etc detail above the waterline, the sign of a real master of his craft.
I have a supply of sheet lead that I cut and use. Would look the same as the lead shot in your pic but you won't need much. I ballasted mine with all the gear in the hull before the deck was added, got it all working then fitted the deck etc. I left it slightly high on the waterline to allow for the top bits. Modern rc gear is now easily available in small form and even the batteries can be sourced in small sizes. I used AA pencells in the model and it sailed for well over an hour, The ESC had a BEC, my own design so shrink wrapped to keep the weight down.