The Ship Model Forum

Sandy's not your only fan, but like I mentioned in the main board before you started this topic. Don't expect too much feedback. Lots of people are reading but not posting!

Anyway great to see it come together.
Another question from my side though. Why did you use this technique for fibreglassing/Mould/Plug? Is it not possible to make a single piece plug (and therefore single piece hull)? It doesn't have a bulbous bow, so I guess it would be possible?

And another question (yeah yeah once I get started...) How many ships did you build? You seem to show quite a few in your picture series!

Neptune

Thanks for asking such intelligent questions.

As I said in the notes,for me I thought this was the easiest way of getting a dividing line down the middle of the plug. The other way is to build a temporary wall down the centre line of a one piece plug. I know lots of modellers us this method and it's in all the books on the subject. They usually use a combination of plastic card and modelling clay.
I decided to split the mould because I wanted to GUARANTEE that the hulls came out of the silicon lined mould easily, complete and without damaging the mould. I might have just about got one out without splitting the plug/mould, but it would have entailed a lot of pulling and levering. I was determined I was not going to go to all this effort and expense, for the mould to self destruct whilst getting the first hull out. THE SILICON IS TOUGH BUT NOT THAT TOUGH.

O I forgot to say that I have a colleague who used this method while working in the film industry, and I figured if it works for a 30 foot sectional dinosaur with scaly skin, it has to work on a model boat!

You ask how many hull moulds I have made this way. The answer is so far 6, (all 1/48th scale) with one more currently under construction and three more in research/planning mode.

Strangely I enjoy being limited by the one scale, a set historic period (1830 to 1914) and limited finished dimensions (the finished model has to fit in my car). I makes you focus very carefully. There are still hundreds and hundreds of vessels to choose from. AND SO FEW HOURS IN THE DAY!

Hi all

You will have seen the strange shaped stern tube mounting bulkhead. Only certain parts of the deck lift off the model and I could see there would be an issue about getting to the stern tube lubricating points. I therefore brought the copper oiling pipes forward, where I could access them. These pipes are supported in the bulkhead (hence four holes).

A small hardwood mounting block for the rudder was added to the stern. I should have really put this on the plug and moulded it in. The same with the wooden block between the two A frames. Bit of an over sight that, but adding them after was not too complicated.

The stern tubes, A frames and props, had been designed and ordered to match the hull. I added the lubricating points myself. The A frames had their legs bent to the correct angle.

USEFUL TIP
The hardware store usually stocks chainsaw files in different sizes. These are inexpensive "rat tail" like files with a square section tang on one end which takes the handle. Cut this part off using a grinder. The remaining file will fit into the chuck of a small electric drill. This will drill or open out stern tube holes in glass fibre hulls easily. It will need a small pilot hole to start it off. The teeth on the file are cut in a spiral so ensure your electric drill is REVERSED, that is running backwards, for it to slowly file its way through. If you don't it will act like a long screw and wind its way in, bursting the hull! Wear a mask.

The stern tubes and A frames were positioned and aligned before being tacked in place with CA glue. Epoxy was then used to secure them permanently, with masking tape being used to make sure the epoxy did not run out onto the outer surface of the hull.

Reading & enjoying Steve

And learning!!

Hi all

The pictures show the installation of the stern tube support bulkhead. The area aft of this will be permanently decked over, the section of deck forward will be removable.
Grey plastic dust covers have been fitted to the oiling tubes to keep debris and paint out during the build.
The transverse deck beams have the correct camber shape formed into their top surface. The longitudinal deck support timbers and deck edge shelf are also in the process of being installed.
These timbers are not substantial as I am desperate to keep the weight down and the strength comes mainly from the hull skin anyway.

Hi all

About this stage the outside of the hull mould was carefully rubbed down with some fine wet and dry paper. Care was taken not to rub too hard or damage the detail. The port holes could have been drilled right through and subsequently glazed, but I decided to just leave them as they were, as it was difficult to tell they were not actually glazed. They were moulded to the correct depth, so when the whole model was finished I carefully painted them with a tiny pool of gloss black paint. The end result was effective and waterproof.

In the mean time the hull exterior was finished in red primer. The choice of primer colour is personal. I find it easier to see any faults and discrepancies in the red rather than grey.

The small aluminium pivot for the top of the rudder post was glued to the inner edge of the hull and the mounting blocks for the rudder servo were installed in the accessible hull area beneath the aft 88mm gun.

The engine mounting bulkhead was cut from 2.5mm plastic and installed in the correct position. This would carry the two 540 type motors running on 6V.

Hi all

The rudder and tiller arrangements on this working model are probably worth a closer look.

Like many early destroyers, the rudder on the original vessel was hung over the stern and connected to a tiller mounted on the surface of the aft deck. This was itself covered with a solid raised deck section. The moving tiller however was still clearly seen below this.

This is the third model I have built with this type of arrangement, and I have worked out how to make it both function reliably and look correct to scale.

The rod, chain, cable and associated pulley arrangements along the deck edge were reproduced (non-functioning) up to and including the furthest pulley aft. Hidden behind this pulley and practically invisible under the edge of the raised deck was a 3mm hole. Through this was threaded a short length of (annealed) bent copper tube. This was "S" shaped and re-directed the direction of "pull" from the tiller to below deck and aimed it toward the servo. The mouths of these tubes should be slightly bell mouthed and free from burrs.

As you can see the space in the hull, right in the stern, is limited so the servo was set forward to make access easier.

After the final paint finish was applied to the whole model, the tiller was connected to the servo arm with nylon (fishing) mono filament, in this case 10 pound breaking strain. This was first tied off to a hole in the end of the tiller. This knot was sealed with CA
glue. The mono filament was threaded through the tubes and connected to two swivels, also fishing equipment, on the end of the servo arm. It was too difficult to tie knots here so the mono filament was threaded through two short lengths of soft copper tube. After centralising the rudder and adjusting for tension these tubes were crimped with pliers. A couple of drops of light oil were run down the copper tubes.

This closed loop system, like an aircraft rudder, has work faultlessly for years. MAKE SURE THE RUDDER IS QUITE LOOSE IN ITS SWIVELS SO AS NOT TO PUT EXCESSIVE STRAIN ON ANY PART OF THE SYSTEM.

That's some pretty neat work there! Did you make the linkage part on the servo yourself?
A pretty small space to work in, I see why you opted for a fibreglass hull !

Neptune

I have made a few modified arms for servos over the years. Some were complicated arrangements for working sailing models. This one was a piece of cake.
The aluminium was drilled in the centre with a hole large enough to clear the central retaining screw (for the standard nylon servo cam). Two smaller holes are also drilled either side. These take two small self tappers, which screw into the nylon cam. The end result is the aluminium extension arm is securely fastened to the top of the original nylon cam. At each end of the arm is a small metric bolt which just fits through the eye of the swivel. Two lock nuts secure this to the aluminium arm yet allow the swivel to move freely. The swivel can be mounted on top or underneath the aluminium arm depending on space available. I got this right first time but it's a good idea to put two or three holes at each end of the arm to allow for adjustment of throw and hence rudder movement.

Removing the centre screw still allows one to lift the whole arrangement off the splines should the servo need replacing.

The pictures show it from a different angle so it's a bit easier to understand. They also show the nylon mono filament as it emerges just behind the dummy pulley, turns round a small nylon post and connects with the end of the tiller.

Hi all

The GRP fore deck went into place quite neatly as previously described, and only a small amount of filler was required to make good the joint. Some of the external detail was also added along the fore deck edge at the same time.

The propeller guards were made from two sizes of soft galvanized steel which was (soft) soldered together, then glued into pre drilled holes. These guards protected the propeller blades (on the prototype and the model!) who's radius extends outside the edge of the hull line.

In the next post I make a start on the bridge and main deck structures.

Hi all

From the photos you can see I had started to lay some of the deck. Again trying to keep weight down, I used 1.5mm plastic card stuck down onto the deck edge and the deck support timbers, using CA glue. There was no need to lay it all in one piece, so I cut sections to shape and used butt joints half way along the deck beams.
The underside of the plastic card was first sandpapered with fine paper to aid adhesion and speed setting time for the glue. Small clamps and masking tape were used to hold the plastic card in place (forming the deck camber) while the glue set.
I paid particular attention to where the deck met the top of the hull edge. The diagram shows how the deck was set back slightly to create a realistic edge. Only minor filling was needed. The two removable deck sections will be dealt with later. The hull had now become a "tube" and was very strong and light weight.

The other main deck structures, including the bridge, WT room and boiler room roof were traced from the plans in "exploded" component form onto three sheets of A4 tracing paper. I scanned these into the computer and printed them onto 1.5mm plastic card. Each component was also labelled to help me when they were being cut out.

The original idea was to build the boiler room roof as a long shallow and hollow box structure, but it became apparent that in plastic card this would lack the rigidity necessary for this length of structure. I therefore started with a balsa wood core and used the plastic card elements to clad it.
This worked well. Again the plastic card was sandpapered on the reverse side before being stuck to the balsa wood core with CA glue.

Fascinating stuff, Steve.

As a matter of interest, where did you get the running gear from?

Also, have you ever had expansion problems with strene on wood or vice versa, especially with a black boat and, meagre granted here, sunlight/heat?

All the best
Sandy

Sandy

I've contacted you directly re the props.

I have never experienced any major issues with styrene decks on wooden frames. Once on a very very hot sunny day (a rarity here) the long thin removable deck section on another model, curved up very slightly at one end (about 1.5mm). This returned to place when the model was moved into the shade.

The sections of deck glued down onto the cross beams and hull (on the same model) never moved at all. I did make a point of not skimping on the CA glue when I laid the deck. I wet the whole glued surface. I think that helps. Contact adhesive would probably be a bad choice

I believe ABS is less prone to thermal movement than high impact polystyrene. I have some of this in stock and intend trying it out on the next build.

Hi all

Pressing on with assembling the bridge, WT room and boiler room roof.
This was all pretty basic stuff, cutting out the components printed onto the three A4 sheets of 1.5mm plastic card and sticking them together with solvent weld.

For those of you not familiar with the vessel I have included a picture of the finished deck structure on the model so you can see what I was aiming towards. By printing onto the plastic card I was able to transfer, fairly accurately, the elements I needed from the original plans. There was also no risk of lines or location points being smudged as the printing was waterproof and permanent.

As the basic box sections of the structure came together I inserted light weight wooden blocks into the internal corners to add strength and ensure squareness. All the time I was still trying to keep the weight to a minimum.

Hi all

The front of the bridge is curved so I installed a softwood block internally to act as a former. The plastic card front to the (lower) bridge structure was curved around this and held in place while the glue set.

I cut the upper bridge and bridge wings from thin ply. I could not find a decent picture of the the bridge on these vessels so I had no idea what the floor of these bridge wings were made of.

Options were;-
Sheet steel with paint or linolium covering.
Wooden planked decking.
Wooden or perforated metal grating.

The original photographs I had access to did not show much light under the wings, just heavy shadow, so I concluded that even if they were open gratings they were subsequently covered with something solid to keep out wind and spray. I know this was standard practice on early British destroyers, where officers would obtain pieces of linolium (cortecene) from the stores and nail it down onto the open slatted floor of the flying bridge in a vain attempt to fend off the spray.

On my model I decided on wooden planking for the wings and a painted (0.25mm plastic card) floor to the covered bridge and wheel house. From an aesthetic point of view I thought the varnished floor of the bridge wings would break up the sombre dark grey and add a little detail.

Hi all

The upper bridge and bridge wings are raised above the forward deck house structure and supported on short angled legs. I have no idea why this was on the prototype vessel, or what the reason was. On photos you can clearly see daylight through the gap though.
On my model I installed the upper bridge floor and having allowed the glue to set I inserted the short angled support legs (cut from wire) into pre drilled holes.

If anyone wants to enlighten me on why this slightly odd construction design was adopted on these (and it would appear other) German destroyers and torpedo boats I would be very happy. Why a gap??

The corners of the WT room and the join of the curved front of the deck house were reinforced with self adhesive aluminium foil embossed on the reverse to represent rivets. Non of the photos I obtained had enough detail to pick this out but I thought it would probably have been the case (pre-dating seam welding) plus it added extra surface detail. Port holes were drilled small then opened out with a tapered ream to accept brass port hole surrounds. These would be glazed (after the final painting) with small perspex slugs.

Hi all

As I previously said the boiler room roof was formed around a core of balsa wood. This was clad with the printed plastic card elements. Printing on the plastic was inspired as it meant all the locating positions for the vast majority of the detail were already in place, with no need to transpose measurements from the plan, and thus one less chance of a mistake (time saving too if you follow the old rule "measure twice cut once").

The frame work of the wheel house was also cut out and assembled in place.

The rear wall of the WT room had various small doors and storage lockers built into it (the shallow one looks like a flag locker to me). These were cut out and stuck in place with polyweld. Small brass pins were eventually used as handles for these, and short lengths of 0.5mm brass wire were cut and fitted as hinges.

The (pressed steel) doors to the WT room and the other deck houses were also printed onto the plastic card and most were also cut out at this stage and glued in place.The same process as above was used to add handles and hinges.

Hi all


The wheel house construction continued. The plans seem to indicate a triangular cross section structure projecting forward into the wheel house (arrowed). I figured this was possibly some sort of service trunking for the search light? Anyway I fabricated this from plastic card and inserted it before installing the chart room/wheel house roof.

The window fame surrounds were very carefully cut out of the printed sheet and installed, together with clear plastic window glazing before the roof was installed. I painted the interior of the chart room and WT room dark green. The glazed windows were masked out before the exterior painting stage.

A small plastic card lip was added to the edge of the bridge wings. This gave a neat edge and also gave a slightly more substantial edge to fit the stanchions into.

The steps and hand grips up to the chart room and WT room were also added.

Under the bridge wings there were some metal supports which were made from plastic card strip. This whole section of the deck and superstructure will lift off, to gain access to the interior hull. The lattice-work metal bridge wing supports, so much a feature of these German vessels, will remain attached to the hull, but more of this detail later.

That's some sharp work and creative thinking there! I guess we can forgive you the "artist licence style of creative thinking" for those bridge wing floors. Either way you won't be too far off with your guess (and it looks nice )

Sorry for jumping perhaps in your sequence, but do you have any pictures of the open hull with the electronics installed? And which parts of superstructure are removable? How did you attach/keep the removable pieces in place?

Hi Neptune

Thanks for showing interest. I seem to have got �locked into� posting the build in the order the model was actually put together, hence my skip from hull construction to deck house build, that�s the order I worked.

You are quite right though, it will probably make more sense to others if I post some pictures of the internal arrangements at this stage.

The internals were designed not to be over complicated. I thought initially I could fit in two 6V, 4.5 amp hour lead acid batteries, for the main power, but it became apparent, with the first flotation test, that I only had sufficient buoyancy for one battery of this size. This proved more than adequate for the job though.

These vessels were really shallow and slim (particularly from amid ships forward). I tried the internal components in various places to get the trim right. The hull had surprisingly less volume than my previous build, HMS Velox 1904.

I have a diagram of the eventual internal layout of V105, but the explanatory text might be a bit small. I�ll put it in here, along with actual internal photos during construction. I will show final internals at the end of the build as a few mods were necessary. You will see the strange box ducting (blue arrow). This is part of the smoke generator I designed to fit in this and my other models. The servo with a cam and 2 micro switches (yellow arrow) operates the smoke generator and blower fan.

Details of deck hatches and securing methods will follow shortly.