I'm intending to step completely outside of my comfort zone and build a working model of an ironclad, for both electric and sail – about a 40 inch hull.

It will be impossible to get any access through the deck because of the rigging and so the hull will be split horizontally. To avoid building a sail powered submarine the lower hull will have an internal upstand extending to he underside of the deck.

To keep the horizontal split line as tight and as true as possible, I thought that a fibreglass hull would be preferable, although the ram bow and extreme tumblehome don't make things easy. If the moulding were tinted black, that would also help to hide any hull scratches , as I want to use it regularly.

Fibreglass is an alien material to me and I really don't want to expend time experimenting and trying to get a decent result – especially as my workshop is the spare bedroom (no shed or garage) and my wife not unreasonably objects to fibreglass smells.

Can anyone recommend any professional / semi professional who might cast a one-off from my plug ? Obviously I need to understand their requirements before actually building the plug and seeing when level of surface detail can be incorporated.

Paul

Appreciate the response Ashley and a foam plug isn't something that I had considered and a material I haven't worked with before.

Making a one piece hull and then slicing it, would be ideal but the upstand then has to be joined to the sides – because of the extreme tumblehome, the upstand either has to follow the inner contour of the upper hull (very curvy in cross section) or if the upstand is vertical, it has to be inset several inches as the beam at the cutline is about half the beam at deck level ! It would be stronger if it were moulded in one piece.

On the negative side, I'm not very keen on doing a series of layups strong enough to support at least 10 pounds of external false keel and sanding the surface smooth . The narrow ram bow could also be a problem..

Having said that, its making me feel that glass skinning a planked hull inside and out might be the easiest approach.

Still open for suggestions.

Paul

The prototype is Le Redoubtable of 1875, a full rigged, ram bow, central battery iornclad, with extreme tumblhome.

Sorry but my photos are not JPEGs and I am struggling to post them as I am very IT challenged

The hull is a unique shape, so 'deepening' it is not an option. Whilst many models can be sailed with internal ballast only, this can often restrict them to light winds or require you to shorten sail in much more than a breeze. Also they do tend to heel unrealistically.

I have an rc three masted topsail schooner with a detachable false keel, which I have made progressively deeper and it sails well in a range of conditions. The keel is completely invisible in the water. .

Transporting a sailing model from house to car, car to lakeside nd then launching, is physically awkward. On has to be very careful not to snag the yards on the doorframes or the mastheads, especially in the car. Holding the model at the bow and stern also places the yards at a nice height for removing eyeballs !

The schooner is quite heavy enough without the extra 8 pound s of lead and at a fit 69 years of age, I'm aware that it isn't going to get any easier. Redoubtable also has many vulnerable bits and pieces that will make transport even trickier.

Deepening the hull would not improve the already dubious sailing potential of what is already a pretty tubby hull.

Anyhow, thats the reason for not distorting the hull and going for a removable external keel – plus it means the model can be displayed without the keel.

Although there is plenty of freeboard, the cut line is not much above water level, which means the upstand needs to be more than a lip. However in places the tumblehome means that in places the hull sides are angle inwards at at 45 degrees. I do have a concern about the upper section spreading at the cut line.

Paul

Colin, thanks for posting the photos and those in the link show the extreme hull form very well.

The cut line would be immediately along the top edge of the pale hull stripe, just above the waterline. The stripe is part of an armoured belt and stands proud of the hull surface, so a natural split point .Whilst running with electric power probably won't create much water pressure, heeling under sail might be another matter. Consequently I prefer the upstand to be as tall as possible – I work on the principle of if it can go wrong it will. Also this is not a model on could easily modify if there were problems.

Rudder servo, motor, esc and lipo will be in the lower hull, and probably the smoke unit as well.

Because I want control of jibs, square sails on all 3 masts and fore/aft sails on all 3 masts, there is a lot of gubbins to cram into the top half of the hull, which is pretty narrow due to the tumblehome. It just isn't possible to mount sail servos in the lower hull because it wouldn't be practical to connect/disconnect them.

Once the top and bottom hull sections are lifted apart – I would only need to unplug a single multi-pin connector for the radio, to free them.

To actually do any adjustments/repairs to the sail controls, I would invert the entire top hull/masts and hang it form a couple of rings protruding from the underside of the deck for that purpose. There simply isn't any other way to do it !

My experience with the schooner suggests that controlling more than one sail from one servo, creates problems and makes adjustments very difficult. My solution is to use one servo per mast of square sails (3), one servo for each fore and aft sail (3) and one for all the jibs(1). One servo for rudder and one channel for the motor ESC. 8 servos + ESC.

Being mainly a scale glider builder, I have an all singing, all dancing transmitter and that will allow individual adjustment of each servo. In turn, the load on each servo is much reduced, so I can use smaller. The lines for each sail control can then be far more direct and simpler.

However I'm drifting away from the issue of the upstand and whether to cast a GRP hull, go GEP/foam or build in wood and glass skin inside and outside.

Paul

Ashley – our posts crossed.

Your suggestion to do without sails is of course eminently sensible and only an idiot would attempt to sail such a model. My schooner entrances me with its appearance on the water and its also really interesting to sail.

Sailing a square rigger will be an even greater challenge and thats the goal, regardless of the grief. I aim to make it as detailed as my modest skills allow and I am well aware that such a 'fussy' model is going to be vulnerable to damage – mainly in transportation and launching probably.

However I throw my scale gliders off hills in 10-30mph winds so whilst damage is upsetting, it has to be accepted as part of the risk to enjoy flying.

Back to hulls – if I build in wood and glass skin it – cn the fibreglass resin be tinted black ? I know its possible with gelcote but what about the resin itself ?

Paul

Colin / Steve – thanks for flagging up Eze-cote. Something I was aware of but have not actually used. and will be studying the video.

How strong is the resulting surface in dent resistance ? is there a need or is it even possible to use 2 layers ?

I would be using it over planking I think rather than foam as I feel I can plank more precisely. Can it be tinted ?

My reason for tinting is purely so that any paint scrapes don't create pal scratches.

Ashley – is London your model ? I do like steam powered ships of the line and they are rarely modelled.

For me part of the intrigue is to use the sails although I know the motor will often be needed to tack or avoid the bank. I do have an old Imai plastic kit of the similar Le Napoleon which I my convert to sail, although it is a little small.

Paul

Ray – I will build to 1/100 and that gives a 39 inch hull to the tip of the ram bow – obviously the bowsprit extends well beyond that. Beam is a little over 7.5 inches and the hull midships has vertical sides and flat underside – quite tubby. Freeboard is 2 inches.

I did envisage great problems in gathering drawings and details but a set of drawings was kindly donated to me, an excellent book and a three part article sourced. A French modeller sent me details of the ships boats and a lot on armament. In a perfect world I could do with a few more details of the gun mountings and some more photos of the inside of the bulwarks but really I have moe than I could have ever imagined.

I would love to build Redoubtable with a 6 foot hull but is simply not viable and would need a trailer to transport it. At 39 inches, I can carry it out of the house without help and get it into and out of the car. Much bigger and the rig wouldn't fit in the car (Honda Jazz). It is fractionally bigger than my schooner and I find that suits me fine.

But do you see problems I haven't identified ?

Colin – quite agree about a sturdy prow – the ram bow will be fully functional ! Bowsprits are definitely vulnerable – I was planning on using a knitting needle. I do like the idea of it being sprung. My schooner has a very powerful motor and I've found that sudden application of reverse, avoids any bowsprit damage.

Paul