Tag Archives: Miss Severn

‘Miss Severn’ 1922 Gold Cup Racer – Mack Models 1:8 (Part 7)

Having finished the engine diversion it was time to get back onto actually building the Miss Severn model. Not surprisingly these activities have focused around the engine bay and installing the new engine model in there.

In order to try out ideas and plan the installation of components, without the need to constantly handle the engine, I reverse engineered a CAD model of the boat’s hull and installed the virtual engine within it. That allowed me to quickly try different layouts of equipment.

One of the first activities was to manufacture an oil tank for the bay. I’ve no idea what size the Hispano engine requires, but I do know that the Hawker Hurricane with the Rolls-Royce Merlin had a 7 gallon tank. If it was good enough for Sydney Camm and Rolls-Royce, it’s good enough for me.

A quick box tank design was sketched out with the requisite scale volume (~2.2 fl oz since you ask) and some brass sheet cut and bent into to two C sections to form it. These were then soldered together, which was not the easiest thing as I’m no coppersmith.

A small frame was made from plasticard to support the tank.

The new oil tank in its intended location toward the bows.

The filler cap was left off while I waited for some suitable sized brass tube to be delivered. Once that had arrived a simple cap was soldered up.

The whole affair was then ‘aged’ in another ammonia vapour bath. It was in there rather longer than I intended due to the distraction of our cat. Not a complete disaster though.

There’s not much room between it and the end of the engine. Fitting the oil pipes might be fun later.

That brings me on to the engine mount. Up to now I’ve been using a gash item made from balsa, because it’s easy to work. I wanted to turn that into something more substantial for the final model, so reached for the birch ply.

The inner parts of the mount will be completely hidden in the finished model so are more structural than scaled. It was quite an involved task to get the right shape, despite having built the balsa prototype. There was a lot of trial fitting and fettling before I got the shape I wanted.  Particular attention was paid to getting the mount parallel to the main deck.

The whole affair was then given a quick coat of epoxy resin, and when that had cured, a sand smooth followed by a coat of matt light grey to match the rest of the bay.

The cockpit bulkhead in the engine bay was a bit of a mess as a result of hacking it about to make a hole for the gearbox to fit into. In order to restore order I’ve cut out some 1/64″ ply to act as a veneer and cover up the previous sins.

Having done that I wanted to make sure that it was actually possible to get the engine and gearbox combination into the bay while fitted to the engine  mount. Trying to bolt the engine onto the mount once the latter is in the boat doesn’t bear thinking about.

The fit is exceptionally tight indeed, and requires more force than I’m strictly happy with to get it to snap into position, but it will go. Just. It amuses me to think that when I first set out designing the engine I was concerned it might look a bit lonely in the model’s engine bay.

As you can see from the picture above, having actually got the engine in place, I finished off the exhaust installation.

I’d always imagined that there would be a flexible section between the engine and hull mounted parts. When I was working as an aircraft designer I recall seeing a number of braided high temp pipes when vibration isolation and a degree of flexibility was required, so decided to try and replicate something similar. My design is based on some braided oil hose from a turbo installation left over from my kitcar building days.

 

While the hose might be flexible in real life it certainly didn’t want to go in the curves I wanted it to and was much too stiff for the model. The forces required to get it to lie ‘naturally’ were too much and something was going to break. In the end I resorted to putting in another supporting armature, made from 1/4″ copper brakepipe, to force it into the shape I wanted. The whole affair was then filled with epoxy resin, so it’s anything but flexible now.

As you can see from the above picture, I’ve also made some top-hat ferrules to support the pipe at the cockpit bulkhead end. They are made from brass pipe and sheet, soldered together, then bright nickel plated. They are designed so that the flexible section isn’t hyper-critical on length too. I’ll have a little leeway at both ends when it comes to final assembly.

Next up was a battery.

I’m doing the model to look like a vintage machine might appear today. I’m already committed to that path actually, as the ignition wiring on the engine is modern style. No Gutta Percha insulation there.

Again I went down the 3D printing route because I’m much better at CAD than I am carving! A modern style battery was knocked up in CAD, printed, then used to make a mould for resin casting.

I also scoured the net for some pictures to make decals from. In this case an Exide marine battery of 100Ah capacity. I’ve gone for 12V too, as that is the norm for boats under 40′ apparently.

A quick coat of matt black followed by the decals and an overcoat of satin lacquer resulted in…

I had planned on a fairly detailed battery box for the engine bay, made from photoetched brass sheet, but some research revealed that most of them are simple wooden box affairs. Hence, that’s what I went for in the end.

The planned location for the battery box in the engine bay. The location is determined by the need to keep the positive feed to the starter motor as short as possible. That minimises the voltage drop along the cable during the very high current draw of engine cranking.

I’ve also finalised the installation of the main cooling water feed. In the picture some trial duckboards are installed, but they won’t make it into the final  model.

The latest activities have been centred around making the engine bay door hinges and frames. I decided to photoetch them (as I did on the Chris Craft model) because that avoids any distortion of the thin brass sheet.

Masking up the brass sheet prior to etching. Both sides of the hinge are masked together. So at least if it is slightly out, both sides are out together.
After etching and some fettling to sharpen up the edges and corners. The assembly at the rear shows two halves of the hinge inter leaved. Once the hinge pivot rod is placed in the base of the right angle the individual tabs can be bent around it to form the hinge.

Things aren’t going so well at the moment though, as the first hinge is malformed! One side must’ve moved in the jig during the bending of the tabs, so there is a distinct taper to one wing. If I can’t get it apart I’ll have to start from scratch again which is a couple of days work down the pan.

Yours, 

Not happy of Worcestershire.

Yeah, where the sauce comes from. Lessons on how to pronounce it are available at reasonable rates…

Alternatively just say Wuss-ter-sheer.

Next month, how to pronounce Leominster, Gloucester and Shrewsbury.

Hispano-Suiza 8F (Part 11)

I’ve finally got there. One post more than I thought I’d need, but the two engines are finally complete and a selection of photographs of them added to the galleries under the drop down menus at the top of the page.

There wasn’t much left to finish them really. The main activity required was the completion of the coolant hoses, and the installation of the exhaust studs.

As before the hoses were made up of three parts.

  • A wire core to make sure they keep the right shape during heating.
  • A polystyrene  inner tube to give them the right diameter.
  • An outer sheath of black heat shrink tubing to give a true rubber appearance and thin wall thickness at the ends.
The black tube on the right of the picture is there to form the flared end on the coolant hoses, and is the same diameter as the lugs on the model. It was removed from the formed hose once the heat shrink tube had been shrunk to size.

 

Each hose was run to the model then measured up. A final version was then made from fresh materials, as I’ve found it is necessary to partially shrink the outer onto the assembly then bend it to shape.  Once that’s complete you can remove any wrinkles in the outer by completing the shrinking operation. If you try to slide the heat shrink over a bent inner, like the one in the picture below, the inner wall of the curve wrinkles to an extent that can’t be remove entirely during the heat shrinking process.

Running a dummy hose to the model prior to making the final version.

The process is a bit laborious to be honest and caused me quite a bit of grief. In hindsight it would’ve been a much simpler option if I’d done it in conjunction with fitting the exhausts rather than after. As it was some choice epithets might have been uttered during the operation.

The hoses on the burgundy engine were by far the worst to do as the arrangement is more complex than on the black one because of the location of the water pump.

Other minor work included fitting the cylinder priming pipework on the top of the burgundy engine. For some reason this was quite difficult, which was a surprise as it was relatively straightforward on the black one and they are supposedly identical. Probably just an off day at the modelling desk.

The unfinished left hand end on the priming pipework will be completed once the engine is installed in the ‘Miss Severn’ model.

 

The coolant hoses also required the making of several batches of faux jubilee clips. These are fairly simple but take time. An appropriately sized tube is cut into thin sections and some thin (0.8mm OD) tube soldered to the rim. The whole assemble is bright nickel plated. As a final flourish a brass pin which has had its head slotted and then been bright nickel plated is glued into the cross tube to look like the screw mechanism.

The very last operation was to add the exhaust mounting studs. These are just glued on and have no physical function. They were made from Some M1 threaded rod with M1.0 brass nuts glued in place. The whole affair was then burnished to make them dark. Tedious and unexciting work. 32 required per engine.

If I were make another of these models I’d approach the exhausts in quite a different way I think. I’d keep the flanges separate from the  exhausts themselves, which I have seen on some engines. That would make getting everything aligned much, much easier and would allow the studs to be actually glued into the block.

That’s it for these engines then. A lot of fun to make, but much more involved than I thought it would be. I’d secretly envisaged it taking about half the time it has. I wasted a lot of time and effort though trying to master white metal casting of the aluminium parts before admitting defeat and using the cold casting technique. Now that I know what I’m doing and have all of the moulds to hand I think I could build another engine in 250 – 300 hours. I might even do that as I’d like to have an unmodified aviation version too. They’re not cheap though when you add up the costs of all the nuts and bolts.

Here are some pictures of the finished models. There are a few more in the gallery pages too.

There is a CAD version of the aviation engine ready to go. I just need to get the exhausts printed off…

 

Hispano-Suiza 8F (Part 10)

I had hoped that this would be the last post on the building of these engines, but they will not lie down and give in. The exhausts in particular have been giving me grief.

Given how large they are, and the visual impact of that, I wanted them to have a real metal feel to them. I didn’t think I’d be able to achieve that with painting, and hence decided to build them out of copper and brass (see previous post). They’ve turned out to be some of the most complex soldered items I’ve ever made, but I got there in the end.

Below are the basic items for the burgundy engine which will be going in the Miss Severn type model. They are complete and copper plated, but do not have the inlet and outlet water cooling pipes fitted.

I’m aware that a lot of my pictures show things after they’ve been cleaned up, so here is a picture of one of the exhausts during assembly.

And after clean up, but before plating.

I wanted to plate them to give a homogenous copper look. I have seen welded copper exhausts on one restored boat from this era so, if designed correctly, they must be able to withstand the heat. I doubt brass ever would though, so my headers needed hiding under copper plate. For the doubters, remember they are bolted to an aluminium casting so if your heat management is right, they must be able to work. Aluminium melts about 400°C  (750°F) before copper after all.

After plating with copper I wanted to give them an aged rather than a new polished look. I hit YouTube and tried a number of techniques found there.

I don’t know why, possibly because of the ‘brighteners’ in the copper plating solution, but Sodium Bicarbonate had zero impact. I even left the samples on a radiator overnight in a jar with bicarb solution in the bottom, but they were all still lovely and shiny the morning after. Acetic and citric acids were also tested (OK, vinegar and lemon juice to you) but didn’t really deliver. Immersion in an ammonia solution was exactly the opposite and just way too much. Verdigris all over the place in a very short time. Using burnishing solution worked quite nicely, but gave a blue/black patina, not the brown I was after.

Copper pipe naturally aged by leaving it, lonely and unloved, in my garage for 25 years vs the one on the right ‘aged’ in burnishing fluid.

In the end I found hanging the copper items in an ammonia vapour bath was the best option. You need to make absolutely sure you don’t get any of the neat ammonia solution on the samples though, as that leads to verdigris spots.

That all sounds quite technical and posh, but the reality was a 5L plastic can with a cup full of ammonia solution (34% by vol) in the bottom. The parts were hung off the rim on wires with the top popped back on to limit evaporation. I left the parts in there for about 2 hours, but the temperature in my garage was about 5°C  (41°F) at the time. I doubt they’d need that long in summer.

Having proved the method on some samples, I put the black engine’s exhausts in to treat them. It was a disaster… I’m not sure what happened, but the copper plate started to flake off all over when I removed them. Something must’ve contaminated the surface prior to plating, but I’ve no real idea what. Perhaps my acetone had something in it or the cleaning brush did.

Ho hum…

Whatever, I had an enjoyable afternoon removing all of the copper plate and cleaning up to start again from scratch. Thankfully that went without any further problems.

The burgundy engine has a slightly different and more complex cooling arrangement to the black one, primarily because of the alternative ‘distributor’ rear end arrangement. That required some pipes to feed the water jacket from the pump.

I tried making them from tube, but couldn’t get the tight radius bends I wanted without the tube collapsing. In the end I made them out of solid 4mm rod. Say nothing and no one will know!

Water jacket feed pipes.

Some before and after pictures of the soldering ops.

Risky stuff, as I only used one type of solder, so there was a very real risk of unsoldering old parts while I was adding the new ones.

(I mainly use a cook’s blowtorch for my soldering).

The end result after clean up and a couple of hours in the ammonia vapour bath. The steel spigots are there to mount the exhaust to the engine. The ‘mounting’ bolts will just be for show. The small water outlet at this end of the picture is actually a cold cast bronze part. I thought trying to solder a copper part on there was just pushing my luck too far.

And finally fitted to the engine.

I just need to finish off the rubber hoses to complete the build. They will be similar to those on the black engine.

In addition to the exhausts I’ve also got around to finishing off the clutch. I call it that because I can’t think what else it would be, but I’m not actually certain of it. The thing has a massive mechanical advantage built in to it though, and it’s the only mechanism I can think of that would require that.

If you recall from my previous post I’d designed it in CAD and was intending to build it from photoetched parts.

The first version looked a bit weedy compared to the pics of the real thing, but did at least serve to prove the concept.

Clutch made from 0.9mm brass sheet.

The parts were eventually made from etched  1.5mm brass sheet.

The parts in various states of completion.

After burnishing they were installed on both engines. The thicker section looks much more in scale.

Final version of the clutch release mechanism. The lever turns the rising cam which in turn lifts the central pillar. The bolt on the left hand end provides and adjustable pivot point.

Another area that was finally completed was the carburettor controls on the burgundy engine. The black engine’s controls are much simpler as they don’t have to connect to anything and can be left as they were on an ‘as delivered’ engine.

However, as the burgundy one is going in the boat it does needs connections that can properly link to the cockpit controls. To that end I built a small brass confection out of sheet and tube to simulate some sort of Bowden cable arrangement.

I just need to run some thing black wires into the tubes once it’s installed in the boat.

I’ve finally got around to adding a maker’s nameplate to the burgundy engine too.

As the black engine will be a stand alone model in a little glass case I’ve made some name plates to go with it. They are the usual etched brass affairs, and are replicas of the plates actually fitted on the model. In fact the etch masks were made using the same print files scaled up.

Etched, filed and drilled.

Stained and lacquered.

Having installed the exhausts on the burgundy engine it was possible to start test fitting the thing in the  Miss Severn model. I’d already checked the fit with my rough and ready 3D printed space model, but it was still a bit of a relief to find it went in without any problems.

I can now start to plan the layout of the engine bay. One of the main features of this will be the exhaust run to connect up with the kit’s in the cockpit. That requires some form of flexible coupling and I’m intending to use some braided oil pipe that I have to hand. A rough mock up of the what is planned is shown below and is based on some of the high temp piping that I have seen installed in aircraft.

Further updates on the engine bay fitting and equipping will appear a under  the ‘Miss Severn’ series on this blog.

There will be one more engine one though,  to complete the black engine’s build log.

Hispano-Suiza 8F (Part 8)

I’ve continued to push on with the two Hispano-Suiza engines, but the burgundy coloured one is going in a slightly different direction to the black.

After adding both cylinder banks to it was time to look at the induction manifold.

Previously it had been a single piece casting which worked quite well, especially in pewter. It was very awkward to remove the more delicate cold cast resin part from the mould though. The one installed on the black engine did suffer a little damage that had to be repaired. The arrangement also has no adjustment within it, so getting the cylinders exactly the same height and at 90° to each other becomes critical to a decent fit. I wanted something that was a little more tolerant of minor errors.

The obvious solution was to divide the casting up in to 5 parts, as it is on the real engine.  You quickly appreciate that the original designers must’ve done this to allow for manufacturing tolerances, amongst other reasons.

Hence a revised version was developed in CAD and sent off to be printed.

The revised parts fresh from the 3D print bureau with the print supports still attached.
The parts after a quick clean up. The manifold is symmetrical about the centre, so I only need one side printing to make the mould for both.

The link piece in the centre of the picture above is deliberately slightly over length so that it can be trimmed to a perfect fit on the engine, giving me the slight adjustment I wanted.

The cold cast components. The left hand part has yet to be polished.

The link pieces were glued to the central casting and the outer parts dry assembled on the engine using 1 mm bolts to locate them accurately. Then commenced the trial-fettle-trial sequence making sure I reduced each link piece equally in length. During the process I also filed off the locating pegs on the bases of the side pieces because they were more trouble than they were worth to be honest.

The result is shown below, and a it is definitely better fit than previously, though there’s no actual visual difference between the two arrangements.

The parts can’t be permanently fitted though until the carb has been attached as well as the plugs, ignition leads and their guide tubes in the V.

Speaking of ignition systems brings me on to the main change on this model. The black engine retains the magneto ignition system of the aircraft engine. The full Auto Engine Works marine conversion changed this to a coil/distributor version with dynamo. This makes more sense in a boat where swinging the prop is problematic to say the least, and a starter motor with charging system almost essential.

I wanted to model this arrangement on the burgundy engine, so it was back to CAD to develop…

Once again a set of .STL files were created and emailed to the 3D print bureau and 3 or 4 days later the printed parts arrived in the post.

STL = STereoLithographic which was the process used in the earliest 3D printers. The processes have changed, but the file type has stuck.

The parts with print support structure.
And cleaned up ready to make moulds from.

Moulds were taken and the parts cast in polyurethane resin. The dynamo and front face of the water pump were cold cast because they would have bare ‘metal’ areas I wanted to highlight. Incidentally,  exactly the same resin was used throughout. The only difference is that the cold cast items have 67%, by weight, aluminium powder added. The end housing was also cold cast simply because I had a little mixture left over after the other two, and it seemed a shame to waste it.

The parts cast in resin. The water pump has also been partially assembled in this picture and the bare metal part of the dynamo polished up.

The water pump faceplate came out quite well.

A quick bit of airbrushing later…

The black and silver components were sealed with a satin varnish.

The rest received a coat of burgundy gloss.

Once it had hardened I scraped back the faceplate of the water pump to highlight the company name.

The assembly also included a few photoetch components. The mask for them is shown on the right in the photo below. The large mask is for the exhaust system, including another drill template. I’ll come on to that saga in a future post.

The picture below shows it all assembled and mocked-up in-situ, but no plumbing or wiring has been installed yet. The pipe in the photo below is a trial fit, and I think it needs a smaller diameter one really. A bit inconvenient that, as the lugs are designed to take it. Guess which parts aren’t included in my CAD model…

The distributor assembly on the real engine includes a mechanical means of adjusting the timing advance. To replicate that it was back to CAD again. Then Photoshop to develop more etch masks. I cocked things up slightly on the latter. I forgot to add sprues to them and had to stop the etching process when it was 90% done and the components were still held together. Otherwise they would’ve fallen off the support and disappeared in to the bottom of the etch tank, never to be seen again. 

Two sets of advance and retard mechanism components. The top are fresh from the etch tank. The bottom ones are after clean up.

After the residual flash had been removed the parts were stained and assembled using 0.7 mm brass pins as pivots.

I couldn’t resist mocking the whole thing up again on the rear of the model. It won’t be fitted permanently until I have sorted out the cooling pipe size issue and have installed the spark plugs etc. in the V of the engine, which will be the next job.

The advance and retard mechanism assembled and in place at the rear of the engine.

As an aside: I mentioned last month that I might put some mild weathering on one of the two engines,  but wasn’t sure about the idea. To get an idea of how well it might work I carried out a trial on the scrap gearbox casting left over from when I dropped it.

Pre-weathering
Post weathering trial.

 

I’m reasonably happy with the result,  but need to include a bit more gloss black in the mix to give a more oily appearance. Other than that I think it’s on.

It’s been decided that the black engine will be the standalone desk curio and the burgundy one will go in the Miss Severn boat model. Based on that it’s the black one which will get the weathering treatment.

‘Miss Severn’ 1922 Gold Cup Racer – Mack Models 1:8 (PART 2)

Well hopes of the next post in this series coming along sooner than the last weren’t realised. It’s been quite a long time since the last post on the Miss Severn build. However, progress has been going on in the background albeit slowly, despite illness and such.

In order to make some progress while I wasn’t at my best I polished up some of the fittings that come with the kit. The improvement in them is quite marked. Hard work without being able to use power tools though.

Having completed the basic hull, the next step was to plank it with the mahogany strip provided in the kit. The operation is pretty standard stuff. the planks were fixed with medium grade (as opposed to thin or thick) super glue. It’s a messy job as the glue seeps through the pores in the mahogany so it is almost impossible to stop it getting on your fingers at some point.

Having completed the bottom of the hull the chine line was redrawn and the planks cut back to it.

Chine line

With the chine line re-established planking of the sides commenced.

When the first few layers had been completed the boat was finally freed from the baseboard. It was at this point that I realised I’d messed up a little.

I’d stuck the doublers LS3 and RS3 on the wrong side of deck. Obviously they should be on the underside of it to allow it to be planked on top. It’s not specified in the instructions, probably because it should be obvious, but not having built many boats before it wasn’t to me. Ho-hum. They weren’t that hard to remove anyway with a chisel.

Having cleaned the deck up it was possible to get on with the assembly of it and the associated hatches. This was all done as per the instructions.

I took the opportunity to coat the inside of the hull with some expoy resin prior to completimg the decking. It was finished in a coat of mid grey paint.

Completed hatches
Hatches installed with spacers to allow for the hinges later.

The decking was completed which in turn allowed the remainder of the side planking to be finished and sanded flush with it.

Looking more like a Gold Cup Racer now.

At this stage I decided to get on with making some of the cockpit internals for a bit of light relief from all of the sanding, which I struggle with.

First up was the gearbox cover.

The wood in the kit wasn’t especially attractive to be honest, and the fixing tabs were very visible, so I decided to cover the entire assembly, and the rest of the cockpit items, with some mahogany veneer I had to hand. The improvement in the appearance between the veneer and kit parts is shown below.

Kit ‘mahogany’ on the right. Mahogany veneer on the left.
Finished gearbox cover with mahogany veneer applied.

The model I’m building has the optional lighting kit included. In order to hide the switch I decided to adapt the gear lever by installing it on a small rotary switch. The switch I opted for was a 24V, 0.5A Lorlin MTL-21-10 part, which I actually got from Farnell (Order code 2797234). The switch is an 8 position rotary one so each throw is 45°.

The whole assembly was then stained and varnished.

Modified gear lever, adapted to switch the lights on and off.

Next up were the seats which went through the same process.

And the cockpit ceilings and sideboards.

The sideboards, as supplied, had some annoying voids in them which thankfully would be hidden by the veneer.
After a bit of staining and varnishing. Oh, and a new cutting mat.

It was onto the seat squabs and backs next. The squabs were quite straight forward. A little bit of sculpting to make them look like they had been sat on in real life and some piping added around the edges, made from 0.5mm solder wire secured with super glue, and they were ready for sealing and painting. The seat backs were a different story.

The kit parts come fully marked up and just require some careful cutting, carving and sculpting to achieve the desired shape. However, sculpting and carving are not my strong suits, and the final results of my efforts did not make the grade. At all.

So I decided to make them again in a different way. I made some half round balsa strips of the right diameter and glued these to a thin piece of plywood backing as shown below. That at least gave me a nice even shape to seat backs which were then coated with resin, which was allowed to pool a little in the valleys so that they became rounded at the bottom.

Patent tooling for the making of half round balsa strip. Take your oversize square piece and hammer it through the nut and splitter to get two half round strips.

The final result was much more even than I could carve.

The instrument panel was my next project. I started with the instruments themselves. You have to cut the ‘glass’ yourself from clear acetate. I cut out some circles as a guide in masking tape using my sharpened compass. Then stuck them to the acetate, chopped off the corners and then sanded it circular.

The kit tells you to fix the pictures of the instrument faces supplied directly to the acetate with super glue. This was not an unqualified success for me as my glue disolved the print.

Luckily I’d already scanned in the pictures in case I needed extra copies. Bitter experience has taught me to always do this. So I was able to remake them. The second time around I mounted the pictures on some white plasticard and glued that into the bezel, behind the clear acetate glass.

The whole project then took a bit of a lurch to the left…

I was mocking up the dashboard to get a feel for how it would look. In particular I was trying to come up with a more in scale switch assembly than the one supplied in the kit. I ended up with a stainless steel pin in a small eyelet which looked OK. You can see it below next to one of the machined switches supplied in the kit.

The one thing that does leap out at you is that the grain on the instrument panel is very out of scale itself.

The real instrument panel in Miss Severn.

I decided to try a few other woods to see which looked best.

Oh, and I ought to warn you at this point that the kit dash has a hole in it which isn’t used and shouldn’t be there. It’s at about 2 O’clock from the steering column hole.

The drawing of the instrument panel vs the pre-cut kit part. The latter had an extra unwanted hole in my kit.

Having made the samples the decision was made to go with the pear option. Then commenced the job of actually buying enough pear to remake all the parts I’d just finished in mahogany!

While quite a few people advertise that they sell pear veneer and structural veneer, I discovered that most seem to only buy it in when someone orders it, and they can get it. It took me quite some time to actually locate some satisfactory supplies. A couple of months in the end.

The gearbox housing remade in pear is shown below next to the original mahogany one below. The improvement in the scale of the grain is obvious.

A lot of work went into the picture below. Honest!

Cockpit components remade in pear wood.
SS316L 2mm stainless steel strip used as capping for the sideboards. The screws are from US Microscrew P/N M06-30-M-SST PAN. They also sell on Amazon. They are M0.6 x 3.

The cockpit floor was also covered with pear veneer. Simulated brass screws were made using 0.8mm brass rod sanded flush, then scored with a knife blade to simulate a slotted head.

The floor was airbrushed with mahogany stain.

Mocked up in the model prior to the airbrushed stain being removed from the brass screwheads with acetone.

After it had dried the stain was removed from the screw heads with acetone on a fine brush. Be careful if you try this. A slight excess of acetone on the brush and it will pool and strip the stain from the wood around the brass too. Go careful.

CAREFULLY removing the stain with acetone.

And here it is again after the stain has been removed.

The next question was what finish to do the cockpit in? I had assumed that it would be gloss, but the satin looked so good. The problem was how to manage the transition from a satin cockpit to the high gloss hull outer. The latter has to be gloss as it is such a key characteristic of these boats.

In order to help make the decision I’ve decided to make a mock up in both satin and gloss just to see how they compare.

Mock-up in satin to determine the best finish in the cockpit.

I’ll let you know how it goes…

‘Miss Severn’ 1922 Gold Cup Racer – Mack Models 1:8 (Part 3)