I used glassfibre cloth and epoxy resin successfully when building my 46” RAF Crash Tender and I chose to do the same with the Police Boat.
See: https://model-boats.com/builds/view/23951 for the Crash Tender blog.
The application of the cloth and resin serves to strengthen the hull enormously and produces a completely watertight hull, and after additional coats of resin are applied and sanded between coats
resulting in a surface that is absolutely smooth and the perfect substrate for the subsequent paint process.

With the benefit of my previous experience and greater confidence working with these materials I used a ‘fast’ hardener with the resin which gives a working time of 30 minutes and a much shorter curing time where previously I had used a 90 minute ‘slow’ hardener.

The basic process is to cut the cloth roughly to shape with a good margin of overlap and then use masking tape along one edge so that after the resin has been brushed onto the hull the cloth can just be lifted over onto the resin. I then lightly brush the cloth into the resin and push the cloth into any tight angles, without any further resin on the brush, until the weave of the cloth is filled and there are no air pockets and the cloth is completely flat. At this point DO NO MORE as the resin will start to harden and any more fiddling with it will cause the cloth to lift and bubble, less is definitely more in this instance.
The resin should cure completely overnight and can be trimmed with a sharp blade.

I tend to cover a hull in five stages, as there are five ‘faces’ to the hull and thus it’s a five day process for me, this may be time consuming but I think the results are worth the effort.
I will brush on two further coats of resin when the rubbing strakes and gunwales have been added, this will completely fill the weave of the cloth to create a nice flat surface but it’s essential to rub down each coat after curing.

All the materials were bought from ‘Easy Composites’
https://www.easycomposites.co.uk

Before I can apply the final coats of epoxy on the hull I need to fit the two rubbing strakes.
I started with the bottom rubbing strake which runs along the chine where the side skins and bottom skins meet. The strakes meet the external keel at the bow and also extend across the stern.
I used a length of square section of obeche which needed a gentle curve towards the bow, rather than steam the wood I soaked it in water for a few minutes to soften it and then used a heat gun while bending the strip gently to the required curve.

When the wood had cooled and dried the bend was set I did a test fit and drilled very fine holes through the strip so that the modelling pins I use to hold the piece in place would not split the wood.
A 30 minute epoxy was used to fit the strakes on both sides of the hull and stern.

Above this bottom strake is a second rubbing strake and this also meets the keel at the bow and runs across the stern, I used a broader and thinner obeche strip for this and it was prepared and fixed in the same way.

The final pieces to fit will be the gunwales which run around the hull where the sides meet the deck but I will not fit them until I have planked the deck.

The prop-shaft, coupling and motor mount that I ordered from ModelBoatBits has arrived so it seems a good a good time to make up a supporting wedge for the mount to fix to.

I do have a rigid brass motor alignment aid that I used when building the Crash Tender but do you think I can find it in the workshop?....nope! 😡

I expect it will turn up when I need it least! 🤞

Not wanting to waste time I used a length of heat shrink tubing over the motor coupling to make it as rigid as possible, a trick I had seen done elsewhere, and this enabled me to position the motor on its mount in the desired position and measure the angle that the mounting wedge needs to be made to.

I used an offcut of beech that I had in the workshop which I cut to size and then shaped it on the rotary sander that I bought in Lidl, fantastic piece of kit !!.

The wedge was then drilled to take the nylon motor mount and also the fixing screws that pass through the beech block, through the balsa base of the box and into the ply reinforcing plate that I put in during early construction of the hull.

After cleaning up the hole through the keel the prop-shaft was keyed with some abrasive, smeared with some epoxy and then pushed through to mate with the motor coupling. I used the excess epoxy resin around the shaft inside the hull and used some packing tape to stop it running out when I inverted the hull to seal the lower end.

A quick spin on the motor confirmed that the alignment was spot-on and the hull set aside while the epoxy set.

The next step will be to plank the deck.

The kit I’m constructing is a pre-production prototype and consequently it does not have the ‘laser etched planking’ feature that has been subsequently introduced in the final production kits on the ‘upper’ deck and the ‘well’ deck.

This is of no concern to me because I think I prefer to do my own planking anyway but I do have to do a bit of preparatory ‘laying out’ of the deck pattern to ensure that it’s symmetrical and laid in a pleasing fashion.

I have chosen to use 1.6 mm x 9.5 mm obeche hardwood strip-wood (from SLEC) for this with a thin black plasticard caulking between the planks. This is what I did when I constructed the VMW Fire Tender and the result was very effective and visually pleasing.
Obeche has a pleasing grain, takes stain very easily and is also considerably cheaper than mahogany which I feel would be far too ‘dark red’ when finally lacquered.

Because I wanted an outer curved plank around the hull edge I had to cut this from 1.6mm obeche sheet to the correct shape and width as it would be impossible to bend a strip to this extreme curve. These also needed a section trimmed out to allow the bow gunwales to be positioned correctly.

Once both sides were cut and shaped I could then form the ply gunwales to the correct curve by my heating and bending process and glued them down to the deck. I understand that on the production kits these gunwales are now incorporated into the side skins which will make the construction a bit easier.

The remaining outer planks on the hull edges were made from straight lengths of obeche but required some easing cuts so that they could be bent to the curve of the hull. Hopefully these cuts will not be too noticeable in the finished deck.

When all the edge planks were glued in place I temporarily laid out the obeche planking strips with a thin strip of black plasticard as caulking and all held in place with masking tape. The centre plank was arranged to lie over the centre line from bow to stern. The setting out of the planks in this manner confirmed that the layout worked as intended and so I began fixing down the planking from the centre plank of the hull outwards with a fast bonding superglue and the process proved to be quite quick to complete. The side deck planks were equally straightforward but did require some to be carefully shaped in a tapered fashion at each end to fill the remaining gaps.

The rear deck was also planked by working out from the centre plank and thankfully the planking layout matched and followed the bow deck planking perfectly.

The surplus plasticard ‘caulking’ was then trimmed flush to the planks with a very sharp chisel and the entire deck rubbed down with my sanding plate until it was all perfectly smooth.

For those building this model that don’t feel confident enough to do ‘real planking’ will probably want to make use of the laser etched planking on the ply deck panels to achieve a similar result with very minimal effort, but I quite like the challenge of doing it the hard way and the benefit of a slightly better finish.

With all of the deck planking fitted I can now fix the rubbing fenders to the hull where the deck meets the hull sides.
These are made from 6.5mm x 5mm obeche strip steamed and bent to shape and fixed with 30 minute epoxy, unfortunately the strips are not quite long enough to do this in one piece even with the rear rubbing fender in place at the stern so a join has to be made which I hope won’t be too conspicuous. The fender tapers in height from bow to stern and the piece that runs across the stern was made from 5mm x 5mm obeche. All the fenders were ‘pilot drilled’ for the pins that held them in place while the glue set.

The complete hull was then given a further two coats of epoxy resin with a rub down between coats and a final ‘polish’ with 240 grit paper used wet. The resulting finish is perfectly smooth and ready for paint.
The front and rear hatches were fitted with the coamings that will hold the hatches in place.

The rotary disk sander that I bought from Lidl is certainly proving to be very useful in shaping small parts at this stage of the construction. I note that it’s back on sale now (Feb 2019) so if you have the opportunity and £30 ….go buy yourself one!

The next stage will be to assemble the cabin.

The superstructure of the launch is very simple, and from a practical point it was designed to give the crew a large field of view across the river and fast access in and out to deal with emergency situations. Consequently the construction is quite basic and would be quite straightforward if permanently fixed to the boat but this cabin needs to be removable to give access to the battery location and motor.

Because of this the cabin needs to be a strong and rigid structure of its own and yet fit invisibly to the rest of the model, it’s also only a three sided structure because of the open access at the rear and that alone will be a point of weakness to the structure.

I started by glueing the internal bracing strips to the insides of the deck sides as described in the instruction sheet and some strips that form the base for the sides that sit on the deck, these also needs to be sanded to an angle to sit flush on the deck and also create a vertical face that some further strips are fixed to which meet the inside walls of the deck well.

Although all the parts for the cabin are accurately laser cut I chose to do a dry ‘test fit’ using pins and elastic bands to hold the side panels and roof braces together.
This 'dry fit' was neccessary because I had previously decided to fit false obeche panels over the balsa sides and floor of the well to get a better surface to finish in the way I intend, balsa does not have any pleasing grain and does not look good even when stained, so I pinned all these panels in place to account for their addition to the internal dimensions of the well deck.

When I was happy that the geometry of the side panels and front window panels was correct I glued all the roof braces in place and added some reinforcing fillets to make it more rigid, temporary braces were glued across the front and rear of the assembly to keep the whole thing rigid and square during further assembly. The pins and rubber bands were used to pull in the side panels while the aliphatic glue set.

All of this was done with the cabin on the boat so that the correct ‘dry’ fit converted to a permanent fit.

Part 2 will continue with the addition of the front window panels and roof.

Before the front window panels can be added to the cabin structure they need to be shaped to follow the curvature of the front deck as much as possible and then glued together with a reinforcing strip on the back of the joint.

Unfortunately I made an error 😡 when shaping and jointing the parts and had to make some new panels from some thin ply that I had to hand using the old panels as a template, hence the roughly cut window apertures in the ‘photos.

This was unfortunate but I feel better for the confession 🙏.

The new window panel was then glued and pinned to the front of the cabin assembly and left to dry while in the meantime I used my hot air gun to heat and bend the roof panel to the correct curvature.
The roof panel was then pinned and glued in place on the cabin framework and when dry was trimmed with a small plane and the front window panel trimmed down to the roof profile.

I added some additional framing and bracing pieces at the base of the front window panels and a ‘shelf’ which will form part of the dashboard inside the cabin.
I also added some extra framing and an end panel at the rear of the roof and a thin square bead was fitted around the base of the cabin sides and front to improve the appearance where the cabin meets the deck.

Before adding further detail to the cabin I used some Z-Poxy finishing resin on the roof panel to strengthen it and provide a better surface for the paint finish which comprised of one coat of white primer, two coats of gloss ‘Appliance White’ and two coats of gloss lacquer, all with a thorough rub down between.

When all the paint had dried and hardened I gave the exterior of the cabin a first coat of ‘Antique Pine’ stain.

Next I will add some detail to the deck.

Some obeche coaming strips were added to the insides of the well deck and a piece was added at the rear which notches into the side coamings, this required shaping to the curvature of the deck so I wound some masking tape around a pencil to the required diameter and marked a line on the coaming to sand the profile down to. This piece won’t be fixed in place until I have added some internal detail in the rear of the well deck.

Some thin strip was fitted along the sides of the deck which form part of the ‘treads’ that run the length of the cabin sides, these were glued and pinned in place after the edges and ends were rounded.
At this point I applied some ‘Antique Pine’ stain to the bulwarks, rubbing fenders and deck strips.

The position of the treads that run along the deck for the length of the cabin sides were marked by taking a measurement from the plan and transferring this to the deck strips. The tread angle from the plan was determined to be 68 degrees using a digital angle finder (another little bargain find in Lidl for less than a tenner 👍👍) and position marks pencilled on the deck.
I chose to mark and apply these treads as per the model that is in the National Maritime Museum which I’m following to recreate my version of the Police Launch.
These ‘photos have been very helpful in detailing this model.

They can be seen here: https://collections.rmg.co.uk/collections/objects/67590.html

I used some temporary spacer strips along the cabin sides and deck strips and then cut and shaped each tread individually to fit in the desired positions, all the treads were fixed using a couple of dots of superglue making sure that no glue got onto the deck surface as CA and aliphatic glue does affect the way the obeche accepts the wood stain as I discovered when I did some ‘colour tests’ earlier.

The whole deck was then given a very light rub down with a fine abrasive pad before the first of several coats of ‘Teak’ stain was applied.

The contrasting colours of the Antique Pine and Teak stain works well on this model and is in keeping with the wood colours of the NMM model that I’m using as a reference.

EDIT…..I have just noticed that the digital angle finder and digital callipers are back on sale at Lidl on 3rd of March for £9.99 each…….still a bargain 😁👍

https://www.lidl.co.uk/en/MiddleofLidl.htm?articleId=20539

I want to keep the motor cover as compact and in proportion as much as possible so I drew up a design to visualise it and get some practical working dimensions, it also needs to enclose the prop shaft and coupling, and the MT60 connection for the motor so there will not be very much free air space inside.

Because of this the motor cover will need some ventilation as the brushless outrunner motor can’t be water cooled and I don’t want to fit a fan, so the side panels of the box will need some gauze covered slots so that any heat generated can escape, assisted (perhaps) by the rotation of the motors outer ‘rotor’ creating some air movement. I don’t intend to run this boat very fast so I’m hoping that the motor will not get too hot anyway🤞.

I transferred the dimensions of the side panels from my drawings to some 1.5mm obeche panels and cut the side pieces to size and cut out the ventilation slots, some framing pieces and cross braces were fitted internally and the whole assembly glued and clamped together.
Additional framing was added to support the part that covers the shaft and coupling and obeche panels applied to these. Some finishing details were applied around the base and the top to improve the appearance.

The internal framing will later incorporate some small cylindrical neodymium magnets that will hold the motor enclosure down on the deck, I’ll fit these later when the deck floor has been fitted.
The mesh is some of the stainless steel mesh that I had used in the water pickup tube on my RAF Crash Rescue Tender hoses, and this was cut to size and epoxied in place.

The completed enclosure was finished with the same Teak stain as the rest of the boat.

Next up will be an enclosure at the rear to conceal the control electronics.

Whilst I don’t think I’m going to need to cool the motor it got me thinking that it may be a useful experiment to see if the ‘Stick A Fan Blade On The End Of The Rotor’ idea would actually work 🤔
So while waiting for some glue to set on another part of the build I decided to rummage through the junk PC bits box and find an old fan of a suitable size, and I did indeed have on that would fit the bill 😀.

I broke away the outer fan casing to release the motor and blades and then set about separating the fan blade, which proved fairly simple.

The fan blade has an overall diameter of 45mm which is ideal and there’s a moulded-in centre mark so I used a step cutter to open up a hole to 10mm and then a tapered hand reamer to carefully open up the hole to about 11mm which is the diameter of the end bearing stub on the rotor.

The fan was then pushed onto this motor stub until it seated flush on the wide and end of the rotor can and is a very tight friction fit so it doesn’t need any more than that to hold it.

I don’t have a dial gauge but I can tell by eye that the fan is perfectly centred and true and so it shouldn’t cause an imbalance 🤞.

The motor turns clockwise when viewed at the fan end which means that the fan would be pulling air through the side vents , through the stator and around the rotor and would need to exhaust through a new panel cut into the end of the motor enclosure.

The existing motor enclosure still fits perfectly over the motor and its fan and wouldn’t need any other modification than the extra opening and mesh.

So in theory this arrangement will give forced ventilation and cooling of the motor in the event that there is a heat problem.

In practice I’ve yet to wire up the motor to the ESC so I have not been able to run a proper test to check it actually works but I’m pretty confident of it.

This motor cooling arrangement could prove useful to others when faced with a similar situation which I why I decided to conduct the experiment...... and validate my theory.

Just keep your fingers away from the fan blades…..😨