After fitting all of the mahogany border strips to the deck I cut lots of strips of .5mm black plasticard and added them to the inside faces of the mahogany all around the deck and also the central mahogany detail strip.

At this stage I decided to add the last piece of ply deck at the stern, this was cut from fresh 1.5mm ply and the hatch opening formed.
This was glued down, and when set I made a card template of the stern deck, and produced the mahogany edging for this and stuck that down too. The black plasticard ‘caulking’ was added to this as well.

I then started adding the limewood planks and caulking to the front deck working outwards from the centre mahogany strip, the very outer strips continue down the deck sides, some of which a quite narrow, and these required very careful shaping to fit without any gaps which would spoil the look.

These outer strips only extend half way down the deck as I decided to introduce another mahogany strip as a transition point for the planking so that the remaining strips would be parallel to the well deck sides. I felt that this would look far better than to continue the side planking in ever narrowing strips up to the rear deck.

The planking of the lower rear deck seemed to go quite well but the main deck will be a bit more of a challenge for me too as I want to add some borders and detail in contrasting mahogany.
I will also be adding a mahogany detail to the hull that follows the gunwale of the deck that will form a nice edge for the paint finish on the hull.

I began by using some thin cardboard to make some templates for the edging of the foredeck, a 10mm width of mahogany looks to be a nice proportion to the 6.5mm limewood planks.
You might expect that both the port and starboard card templates for the foredeck would be identical back-to-back but surprisingly that is not the case with a variation of a few mm in places. For this reason, separate templates were made and laid onto some 1.5mm mahogany sheet, the outlines marked and very carefully cut from the sheet with a very sharp blade.
With the mahogany, being so thin and the grain being quite coarse, there is the possibility that it can break across the grain, so great care is required to hold the sheet down firmly while being cut.

Similarly, I made card templates for the longer pieces that go back to the stern. The inner edges of all these mahogany pieces were smoothed with some abrasive paper. The outer edges slightly overlap the deck and will be trimmed and contoured before the gunwale strips are applied around the hull at a later stage.

An additional detail is a central mahogany strip on the foredeck that will be echoed on the very rear deck and access hatch. All of these pieces were fixed down with CA and I took great care to get a very tight join between the pieces for the best appearance.

With all of the deck panels firmly glued in place and trimmed all round with a small hand plane I can now consider the rear lower deck floor.

As with the deck panels this is also laser etched with planking lines and at this stage of construction it would be impossible to apply my own planking and caulking lines in the deep recess.
My solution was to cut a piece of 2mm ply to form a new floor panel that I could plank as a separate panel that will be glued down over the laser etched floor. I marked out an aperture on the panel to fit around the motor mounting block.

To date this will be the largest area that I have attempted to plank and I also fear that the process will cause the panel to distort as the glues and resin finishes cure.

I began the process by marking a centre line and fixing down the 1.6mm x 6.5mm limewood strips and the .5mm black plasticard ‘caulking’ lines with superglue and working outwards symmetrically to, hopefully, minimise stresses in the panel.
I found that, although repetitive, the process was quite easy and enjoyable to do as there was no fiddly cutting and trimming of planks to perform.

Once the panel was fully covered I left it for a day or so for the glue to fully cure before trimming off the overlaps around the edges and paring the plasticard caulking down to an even surface with a sharp chisel.
I then cut out the aperture for the motor mounting block and did a test fit. A final rub down with 400 grit abrasive paper resulted in a fine finish ready for the first of several coats of epoxy finishing resin.

Thankfully at this stage there is no significant distortion of the panel so my fears were largely unfounded.

The deck skins in the VMW Marlin kit are laser etched with planking lines for those that are happy to use the panels as they are but, as with the lower deck floors, I’ll be applying my own planking strips with black caulking lines with some additional mahogany detailing.

The deck panels consist of seven separate pieces and are simply glued in place using some aliphatic resin. Being laser cut they all fit together very accurately.

The forward lower deck floor was covered in masking tape to protect the epoxy finish and glued in place as it will not be possible to fit this piece after the decks are fitted.

After applying some TiteBond 2 glue to the forward deck panels I pinned and clamped them in place.
I also used some packing tape to pull the skins down firmly; the packing tape is very strong under tension and is ideal for this.

The side deck pieces were fitted in the same way but I decided to re-make the piece supplied for the very rear of the deck to accommodate the hatch aperture that will give access to the rudder and servo, and also the cooling ‘plumbing’.

At this stage I removed the centre support piece from the area as it doesn't really add anything to the integrity or strength to the hull and its removal gives far better access through the hatch for accessing the rudder servo etc.

Now that the spray rails are fitted, I can give the entire hull another coat of resin to build up a good surface for the paint process.

As with the application of the glassfibre cloth I do this separately for each ‘face’ of the hull to ensure that there are no runs. Fortunately, the Z-Poxy resin has a fast setting and curing time so it’s possible to do the five faces of the hull in an extended day but I choose to do this over the course of a couple of days.

At this stage I’m using cheap disposable brushes that have a tendency to shed a few bristles, which need to be picked out of the resin, and don’t leave the smoothest finish.
This is of little concern because the resin will be rubbed down with wet & dry abrasive between coats and the final coat will be applied with a much better quality brush to achieve the best surface finish.

For now that’s all I need to do to the hull and I can now move onto adding the deck panels and planking.

Before applying another coat of Z-Poxy Finishing Resin I will fit some spray rails onto the lower chines as recommended and detailed in an update to the Marlin construction sheet.
The designer observed that, with the prototype boats built there was an excess of spray from the bow coming over the hull and onto the decks, and that this could be countered by the addition of some short spray rails extending from the bow keel to about 45 cm aft.
I chose to make these from some 4 mm square Obeche that I had in stock but this would need to be steam-formed to follow the line of the chine without snapping or splitting. Fortunately, I have a wallpaper stripper, of which the steam generator is ideal for such a process.

First, I wetted the Obeche strip by standing it in hot water for about ten minutes and then applied steam to the strip for another five minutes until the strip felt quite pliable.
This was then formed around some panel pins on the benchtop to hold the curve as the wood cooled down, this process was sufficient to produce the required curvature that mostly held its shape when fully cooled.

Before fixing the strips to the chines I ‘keyed’ the resin surface of the hull along the chines to aid adhesion of the epoxy resin glue, the strips were then chamfered at an angle to meet the bow keel and drilled with a 1.5mm bit in a pin drill along their length.
The strips were fixed in place with the epoxy and some short brass pins and the ends of these ‘spray rails’ trimmed at a pleasing angle at the ends.

When all was set, I lightly sanded the edges of the rails to round them slightly and the additional coats of resin on the hull will further protect and finish the rails.

The fibreglassing of the hull continued in much the same way as the first piece on the bottom skin, in each case the cloth was brushed into a coat of resin and left to set before trimming and moving onto the next ‘face’ of the hull ending with the stern skin.

After all the excess cloth had been trimmed, I could start the process of flatting the first coat of resin and cloth using my trusty DeWalt Multi Tool with its sanding attachment.

I used a 240grit abrasive and this is sufficient to level out the surface in readiness for the second coat of resin, being very careful not to sand through the cloth to expose the ply skin.
I use the dust extraction attachment in conjunction with the sander to take away the resulting epoxy and fibre ‘dust’ so no face mask is really necessary at this stage.

I will go on to apply the second resin coat later.

Fitting the deck skins should really be the next thing to tackle but as I intend to fully plank the deck, I decided that I should get the slightly messy process of fibre glassing the hull out of the way first as I don’t want anything to spoil the decking surface before I get around to finishing that.

This is a process that I’ve done on all of my boats so I’m fairly well practiced at it by now and I usually apply the fibreglass cloth and resin in five stages, one for each ‘face’ of the hull. The reason for this is that I keep the surface as level as possible which largely eliminates runs in the epoxy coating.

The resin that I favour now is the Z-Poxy finishing resin, which unlike the product I first started using, hardens within three hours and cures overnight sufficiently to be able to rub down in readiness of further coats.

The fibreglass cloth is a light to medium cloth of 50 gramme per square metre that, once wetted with the resin, is easily worked onto the ply hull surface without wrinkling.
The Z-Poxy is easy to work with as it is a mix of 50:50 by weight of resin and hardener and I found that a total weight of about 20 grammes of this is just right for a single ‘face’ of a hull of the size of the Marlin.

The fibreglass cloth is first cut to size and I make it ‘hinge’ onto the hull surface with a couple of small clamps on the keel.
The resin is first applied to the hull surface with a half inch disposable brush and the cloth is laid onto that and the cloth gently brushed down into the resin until it is fully wetted. It’s important not to overbrush the cloth onto the surface as that can cause dragging of the cloth as the resin starts to harden.

With the clamps removed I can then apply some resin to the keel and then fold the cloth onto that area too.

The ‘working’ time of the resin is just 30 minutes so I have to work quite quickly to cover the required area, after that time the resin mix starts to stiffen as the catalyst does its work in the mix.

I’ll leave this overnight to fully cure before trimming off the excess cloth with a craft knife and then prepare the other bottom skin for the same process.

In a previous blog update I described how the forward lower deck floor was planked, finished & fitted but I omitted to mention that before glueing and fixing the floor in place that I had to make some holes through the foremost bulkhead to be able to bring the cabling through from the ESC to the battery & main power switch, both of which will be within the forward cabin.

Whilst these cables could be simply routed in full view within the cabin, and as always, I made it slightly more difficult for myself than that.

I bored some 20mm diameter holes through the bulkhead at a level below the forward deck floor using a right-angle adaptor and a step drill in a power drill.
The angle adaptor allowed me to make the holes through the bulkhead close to the cabin deck floor. I will build a battery box and power switch bracket onto the cabin side of the bulkhead.

On my Thames River Police launch I disguised the power switch as a steering wheel, as in the pictures I’ve added, and I’ll most likely do the same with the Marlin.

BTW.
You may notice my preference for DeWalt power tools and accessories. I believe that the brand is owned by Black & Decker now?

I’ve lost count of the number of ‘lesser’ brands of tools I’ve got through over the years and its usually the gearbox of a drill or the batteries that give out first!

Before I can continue with the fitting the deck skins and planking, I do have to fit the rudder servo.
The plans suggest that this is concealed within a false box or perhaps a seating bench within the rear lower deck area, and while this would be very easy to achieve, I thought I’d like to make things a little more difficult for myself by fitting the servo in the cavity at the stern so that it is totally concealed.

I almost never do thing the easy way 😂.

This will obviously involve incorporating a hatch in the deck to be able to access the servo too. This cavity will be quite cramped as it will enclose the servo, servo linkage and rudder arm as well as the ESC water cooling pickup and exhaust plumbing.

I had previously installed plastic ducting within the hull construction for all of the associated wiring and plumbing so all that remained was to fit a suitable servo mount and servo.

I would like to be able to remove the servo if required, so I used a commercially available aluminium servo mounting and adapted it to be mounted on two ‘stand-off’ pillars secured through the bulkhead with two long bolts. The mount was used in an inverted position to be able to access the mounting bolt heads. This arrangement will allow me to extract the servo, still in its mount, through the access hatch rather than attempt to remove the servo alone.

Before fitting the servo mount I had to fit the rudder assembly and determine the correct height of the mount so that the servo linkage would be at the correct height for smooth operation.
This was more than a bit fiddly but I managed to find the right place and then drilled the two mounting bolt holes through the bulkhead.
The real test of the servo operation was to connect up a servo tester and battery to check that it all worked freely, had sufficient arc for the required rudder movement and without the possibility of fouling with any of the ‘plumbing’ that I’ll be fitting later.
I will have to make the access hatch through the rear deck of sufficient size to be able to get the servo in and out and enough room to fit the rudder and linkage.

At this stage it seems likely that I will remove the central plywood ‘brace’ to make the access hatch practical as this ply piece seems to have no critical structural purpose.