Tag Archives: Mack Models

1:8, Boats

‘MISS SEVERN’ 1922 GOLD CUP RACER – MACK MODELS 1:8 (PART 10)

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I’m still not doing so well on the health front but have been able to make some progress on the Miss Severn model. It’s been a bit two steps forward and one back though.

I have at least finally got around to finishing off the deck fittings.

The cutwater needed several goes at plating to get a satisfactory finish, but we got there in the end.

I’ve also plated the chocks. Only the fairleads remain.

As all of the trial fitting of components in the engine bay is pretty well done I decided to refresh the paint for the final finish. Unfortunately there was a problem…

I thought I’d finished the rear bulkhead of the bay with epoxy resin so was a bit cavalier in my paint choice because epoxy doesn’t care too much. however, I’d forgotten that I’d actually used polyurethane varnish and this reacts badly to cellulose paint.

I was really quite vexed at this point. You know, REALLY vexed and quite upset.

So there then commenced a fun session of sanding down and removing all of the offending mess. After several sessions, of sanding and recoating I finally got back to where I should’ve been all along.

It’s still not as sharp as I’d hoped though.

The next step was priming the hull. No matter how closely you inspect the finish the grey primer always seems to reveal a smattering of defects and blemishes that you’ve somehow managed to miss. So there was a general sanding and filling of pinholes.

I had intended that the strut for the propshaft would be polished brass, but when I offered it up to the boat it looked too toy like, Hence I decided to paint it the hull colour after all. Also, somewhere along the line of resin coats and sanding, the small flat island I carved out for the strut’s base had been lost and needed restoring.

The masking tape is there to mark the outline of the strut and also to protect the surrounding paint while I filed away.
The rod in the bearing is there purely as a paint mask.

The strut comes ready drilled in the kit which wasn’t ideal for me. I did enquire whether it was possible to get an undrilled one but that is how Mack Models receive them. I didn’t want 4 totally out of scale rounded headed screws showing, so counter sunk the holes and used countersunk screws to hide them. Once they were sanded flat the gaps were filled with body putty and that sanded level. The strut is also glued in place using epoxy resin. Just enough to squeeze out the edges and fill any remaining gaps. I fitted the strut before I removed the masking tape in the previous pictures which made cleaning up the excess epoxy very simple. Pull off the tape before the glue is set and you’re left with a nice clean edge that self smooths.

Despite all the prep, the screws are still slightly visible when you get the light at the right angle. I’ve had this before and remain convinced that the filler shrinks very slightly over the days after the instructions tell you it is fully ‘cured’. Hopefully I can remedy that later.

The orange peel finish is due to the use of rattle cans for the paint, but will disappear once the varnish coats are applied.

Having sorted the primer coat and the strut, I finally got around to throwing some paint at the hull. The first attempt went badly. I painted the waterline then masked it off to paint the aquamarine colour. Despite making a test piece, which went fine, the blue reacted with the white paint yet again. To say I was annoyed would be an understatement. I like to think I have some idea of what I’m doing when building models now, but to make a beginners error, twice in quick succession, rather questions that. What was especially annoying was that I made the test piece specifically because I was concerned about the problem as I was mixing paint from different manufacturers and that went perfectly.

There are no pictures of the mess as I was too annoyed to take them. In fact I walked away from the whole thing for a few days to calm down.

A less than enjoyable day was spent sanding all of the mess off, cleaning up and re-priming before a second attempt at painting , with paints all from the same manufacturer (Tamiya), which went OK.

I was using rattle cans for the main areas as the area is a little large for my airbrushes, and modelling desk. They didn’t give me a very sharp water line, so I re-masked that, decanted some of the white paint out of the can and applied it with my airbrush which gave a much sharper result.

Next up will be the staining of the woodwork. The transom is already done. However, I think I will apply a coat of varnish to the hull bottom and sides before I start mucking about with the decks. It’ll protect the paint a little, as it is still quite soft.

In parallel with all of the above I’ve been investigating methods for producing decent gold lettering for the boat name and registration numbers. I’d like them to be a convincing gold, and real gold if at all possible.

I mentioned briefly in an earlier post that I’d been messing about with gold leaf and even done some trials.

The Miss Severn lettering on the cutting mat was a trial of gold leaf application. It’s a mess because I also tested to see how easy it is to remove. (Ans: It isn’t. You get one shot.)

The results of the trials were OK, but not fabulous by any means. However, I did learn that:

        1.  I need a lot more practise to become any good at gold leaf application.
        2.  Gold leaf is more pervasive than glitter.
        3.  I’m not stellar at hand cutting letter masks.

Based on the above, especially the glitter bit, I’ve decided not to let gold leaf anywhere near the lovely black hull this time around. As a result I’ve been investigating other options. In particular I’ve been lusting after a vinyl cutting machine to allow me to produce decent complex paint masks for several years now, and have finally taken the plunge and bought myself a Silhouette Cameo 4 which is thoroughly living up to expectations.

It has already enabled me to cut some decent masks from thin vinyl.

The scalpel is there just for scale. It had nothing to do with the cutting.

Small islands in the text still need a lot of care such as those in the ‘A’s of Annapolis and they are about the limit of what the Cameo 4 will do I think.

By the way, Miss Sally is what the boat is going to be called now, not Miss Severn. The model is quite a way from a replica of Miss Severn at this stage anyway, and it personalises it too.

I’ve also experimented with using the machine to cut gold vinyl.

The top lettering has been airbrushed with gold paint using the mask in the previous picture. The lower lettering is cut from self adhesive gold vinyl foil.

The vinyl foil I used was billed as being 23 microns thick, but my micrometer tells me it is 85 microns including the adhesive. That’s a bit thick to hide under varnish easily. It would take a lot of coats to hide the edges. Hence I’m still trying to locate some real gold self-adhesive foil, like the material they use for shop window lettering. That is billed as being 2-3 microns thick, and having looked closely at the lettering on shop winds in the past I can believe it. I can get small amounts of it from the US, and vast amounts locally for silly money. I haven’t as yet found someone in the UK that will sell me a meter or so of the stuff to play with. The search goes on…

1:8, Boats

‘Miss Severn’ 1922 Gold Cup Racer – Mack Models 1:8 (Part 9)

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It’s been a while since my last post, but progress has been a bit slow and there hasn’t been that much to report.

I’m at the hull varnishing and sanding stage, and the noise of sanding is a problem for me. After a few hours of sanding I have to take a couple of days off doing quiet things to recover as the main feature of my illness is a hyper sensitivity to even modest noise levels. Notwithstanding that I have been progressing steadily, and the enforced breaks have allowed me to progress a few other projects in CAD. These will probably appear on here in the future.

In my last post I left the hull at the bare sanded stage ready for varnishing.

As this boat is going to have gloss black sides with an aquamarine bottom the finish on the sides just has to be smooth. For that reason I’ve chosen to epoxy resin coat it using EasyComposites’ XCR Resin. It’s pretty easy to use and you can recoat in about 40 mins. In fact if you leave it even a few minutes longer than that the subsequent coat suffers badly from “fisheyes” and is very uneven. The short time between coats means that it is easy to build up the thickness for subsequent flatting back. There is an element of self levelling in the resin which leaves a good finish.

Next the dreaded sanding which was undertaken with 120 grit wet/dry paper and finished with 400 grit. It needs to be done wet to avoid clogging of the sandpaper, after a few sessions and breaks I was left with:

It wasn’t all plain sailing though. A few planks sprung loose on the forward starboard side, due to the CA glue not spreading completely under them I suspect, as it was quite a tight curve and the mahogany could’ve done with pre-bending really. When I came to sand the area flat I had to break into virgin wood again to achieve that, which necessitated more coats of resin and sanding..

We got there in the end though.

I had intended to move onto painting, staining and varnishing at this point, but having thought it through I decided to make and trial fit the hull brightwork. Any scuffs and errors could be hidden under the initial coats of paint. It was as well that I did because it suddenly occurred to me that I had completely forgotten the fender rails at the stern. The kit doesn’t have them. It just has the chrome car trim stuck to the side of the hull. Hence, they don’t appear in the instructions.

Cutting the long triangular taper wasn’t the easiest bit of woodwork I’ve ever done as the front section is wafer thin. It stretches about half the length of the actual trim.

The blue tape is there to provide a reference line as it is easier to work to than one drawn on. The slight ridge of the tape gives you something to push up against when fitting the parts, The rubbing strip itself is 1/8″ half round brass from EKP Supplies in Devon. I’d liked to have obtained something more oval in section, but hours of searching on the net didn’t turn anything up in the scale I needed.

Prior to fitting the strip I made up the protection strips at the edges of the transom. They are an awkward shape to guess, so I put some more of my trusty blue tape on the area, cut the rear profile flush with the transom and used a pair of dividers to scribe a parallel line 8mm (1/3″)from the rear face. the tape was then peeled off and stuck onto some sheet brass as a cutting guide. The method worked well.

When the protection strips were added it gave me a reference for the rearmost edge of the fender strip. After being cut to length the ends of the fender strips were finished off and 0.6mm holes drilled at 20mm (3/4″) intervals. Dull, dull, dull.

Measuring and centre popping the holes in the fender strips. The “Miss Severn” on the cutting mat was the result of practising my gold leaf application, from which I learned that I’m not very good at it.

It was almost inevitable that I’d break a number of the 0.6mm drills as they are quite fragile, but thankfully only one of them actually broke off in the brass. It was however a bit of a sod to get out!

All of the brass items in the pictures have been dry/trial fitted. They will ultimately be bright nickel plated and the pins replaced with faux screws.

Next up was the sheerwater rubbing strip. This is just short of a meter (3’3″) long. It has 51 holes in it. Each hole has to be centre popped, drilled deburred and countersunk. There are two strips. And matching 0.5mm holes need to be drilled in the hull…

So that was 2 days of exciting activity especially when I was down to my last 0.6mm drill with more on order. As I can’t use power tools all the holes were drilled with a manual pin vice. Dull.

They look pretty good though.

I should’ve mentioned that I also fitted the cutwater to give me the forward reference for the sheerwater strips (80 more holes!). The version in the picture is the Mk.II. Even then the plate at the top wasn’t a stellar fit and was also too thin. The one one the real boat is quite a chunky item.

I glibly decided to remake it in a thicker section. The combination of the thin cutwater sheet and thicker fairlead plate proved a real trial to solder, particularly as I don’t have solders of different melting temps. Having wasted half a day trying to solder it in accurately whilst not unzipping everything else, and failing, I decided that some form of jig was required, One that could withstand my cook’s blowtorch on it.

Whilst mulling over the problem in bed, I recalled I had some Plaster of Paris in the garage that I bought for some long forgotten project and never used…

Next morning I super glued the cutwater together with CA glue and stuffed it in some Plaster de gay Paris and left it to set for a couple of hours. Et voilà! Un soldering jig (anyone remember Miles Kington’s Franglais column in Punch?).

The CA glue was removed from the cutwater and the whole thing soldered up in the rather rough and ready jig. Which worked. It still took a couple of goes to get it good enough though.

The plate still needs a proper polishing to get all the scratches out prior to plating.
I know the sheerwater rails aren’t right. they’re only tacked in place for now.

That brings you up to date on the hull work so far.

I have also done a little work on the engine bay doors which will need to be in place for the staining operations if they are to come out the exact same tones. The insides have been stained and varnished, and the cross braces fitted in a contrasting colour of boxwood.

Now I really do need to get onto the staining and painting ops.

1:8, Boats

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

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Well, this post has been delayed a bit more than I expected, but I’ve been taking a bit of time off to do the ill thing again. They don’t hand out medical retirement to anyone. You have to work at it constantly. Hence, the modelling activity has dropped off for a while, though I have been able to do some background CAD work for some other modelling projects which may appear in the future.

I’m back at the modelling table now though, so hopefully normal service will be resumed.

In my last post I left it with a hinge that I’d made for the engine bay doors being malformed. Despite trying, the thing wasn’t recoverable and I ended up having to photoetch another. Given the time and faff of making these pieces I think I might invest some money (aka known as spending) and get a professional etching house to produce me an A5 sheet packed with the things. It will save me a lot of time, effort and angst in the future.

A hinge. Made properly.
The hinges mocked-up on the model. Almost 500 hundred holes ended up being drilled to fit these things!
The pitch of the hinge leaves is about 2mm.

Apart from the bright nickel plating, that is the hinges complete. I’ll plate them when I am doing some other plating work.

Having completed the hinges I moved on to sorting out the engine bay and preparing everything for the installation of the engine and various other components. They won’t actually go in until I have finished sanding down the hull though, because of the dust.

First up was filling the unsightly hole dug out while I was trying to fit the mock-up engine. You won’t actually be able to see this when the engine is in place, but I can’t leave it like it is. It’d irritate me too much.

I mixed up some super fine white Milliput and wrapped it in some clingfilm. Then I pushed it into the hole to be filled and used the mock-up engine to press in the voids required to accommodate it.

Milliput wrapped in clingfilm

Once the Milliput had cured it was removed from the model, unwrapped and filed to the final shape, including adding some relief to the indentations for the engine.

Clingfilm removed and cleaned up.

Here it is back in the model. It will eventually be epoxyed in place and any remaining gaps filled with modelling filler.

Back in situ. The remaining gaps will be filled with filler.

Having painted the engine mounting I’ve finally got around to attaching the engine to it permanently. I had briefly toyed with the idea of actually using the mounting bolts to hold it in place, but trying to get all the studs exactly lined up with the holes was a challenge I ducked.

Instead the engine subframes were glued to the mounting using epoxy glue and the studs glued in afterwards. This also means it is quite easy to get all of the threads showing above the nuts an even length.

Engine mounting studs glued in place.
Studs awaiting the installation of the gearbox. The pegs are there to hold the subframe in place while the epoxy glue cures.

With the engine mounted properly on the frame I could get on with finalising some of the smaller installations and connections. Mainly wiring. Below is the starter motor wiring installation. A small ‘solenoid’ has been made from plastic stock.

The oil lines to and from the tank have also been mocked up on the bench. The idea is that I will fit them to the engine prior to it being installed. The pipes can then be fed into the oil tank when the engine is in the model. There is free space within the tank so the length of the pipes won’t be critical.

Red fishing line has been used to connect the positive sides of the coils up. The nuts are M0.6.

Note to self: remember to dust the damn thing before you photograph it.

One other significant development at MBIQ Mansions has been the acquisition of a ‘4k’ resin 3D printer. A Phrozen Sonic Mini 4K to be exact. The 4K refers to the resolution in the XY plane which is 35 microns, or in good old inkjet speak, 722dpi. (1 micron=0.001mm or about 0.00004″)

I think the output from the printer is quite amazing. They are a bit temperamental though, and take some trial and error with settings to get going well. There is however a very helpful forum of other users to refer questions to. I’ve also invested in an Anycubic print washing and curing station, which I would highly recommend as it makes cleaning the prints so much easier. Also invest in lots and lots of Isopropyl Alcohol and kitchen paper towels…

Below is a sample of the printer’s output. Clockwise from top left:

  • 35 micron Output from the Phrozen Sonic Mini 4K machine.
  • Print at 50 micron resolution from a professional print house .
  • British tight-wallet’s preferred stamp.
  • Another Phrozen output which was subject to overly aggressive cleaning before being fully cured. Hence the bits of text broken off. Lesson learned!

I’ve used the printer to produce a selection of P-clips and connectors for the wiring looms on the model.

While I was ill I also took the time to knock up a notional wiring diagram for the model to allow me to visualise what wires should be going where. The idea being that the wiring installation should bear some relation to reality when installed.

The 3D printer also allowed me to produce some electrical junction boxes in various sizes. For what it is worth, and in the absence of any other information, I’ve gone for a Raychem style of wiring loom with Mil-DTL-38999 connectors. Those were the ones that we used to use on the aircraft and I always thought they looked quite tidy.

Notional wiring loom for the engine. There isn’t much wiring at all on this era of engine though.

The clutch mechanism has also been finalised and a hole drilled in the bulkhead to accommodate it. A piece left over from the Hasegawa Clerget 9F push rods makes a nice simulated rubber grommet. Well, it will when it’s painted black.

The copper pipe for the main water feed has been manufactured and trial fitted, including saddle clips etc. The connecting pipe to the engine has been deliberately made a little slack on the pipe so that it will be easy to slip over when the engine is finally installed. The jubilee clips have yet to be made.

I initially used the wiring provided in the kit to connect up the various lights. However, it was very heavy duty, not that flexible and technically complete overkill. I’ve finally got fed up with it and replaced it with some much smaller gauge PTFE coated wire which is much nicer to work with and a lot more flexible. Just to make sure that the thinner wiring wasn’t going to cause problems with voltage drop I mocked up the wiring on a breadboard before it was installed

I’ve also replaced the rice bulb lamp in the dashboard with a 3mm LED. These lights won’t be easily replaceable if they fail and the LED should be much more reliable as well as drawing less current. The LED was a hard blue/white light though, so I painted it with some clear orange to give it the same colour temperature as an incandescent bulb.

L-R Hard white LED in the bow lamp. Hard white painted with clear orange. True incandescent bulb.

The 3D printer has really opened up a world of opportunity for me in my modelling. It’s immediately become my goto solution for many bespoke items. It’s much faster for me to bang something out in CAD and print it than make by hand. The results are higher quality too.

Fire Extinguisher and cone, with a few more P-clips.

Fire extinguisher mounting bracket.

The fire extinguisher was a fun item to make. The 3D print needed a little sanding smooth before painting and a custom decal had to be made, but the final result is quite pleasing. The handle is made from a ready meal tin’s foil. I didn’t think the printer could handle the thinness required.

After the break in progress, and to get me back into the groove I went for a quick hit activity and decided to assemble the dashboard. Having done that and trial fitted it in the model I discovered that the steering mounting hole suggested in the Mack kit was a little low for my liking. The steering wheel is quite high in the real boat, but quite low in the model. I marked and drilled a new hole which was where I wanted it, but that did leave me with the problem of the unsightly old hole.

Fortunately the real boat has an additional switch which has been omitted from the kit. I had wondered what I was going to do about it, but it proved a fortuitous way of covering up the unwanted hole in the dash. You can see the switch I mean immediately to the right of the steering column in the photo below.

I’m not at all sure what the switch does or even looks like in detail as the picture above is the only one I have of it. However a PASWAG* design was produced and printed.

*Pure and simple wild arsed guess.

Here it is fitted in the dashboard with the revised steering column hole above left.

Trial fitted in the model with the steering in place. It’s still a bit low, but to change that would require extensive mods.

I did think about trying to cast the switch, but decided that the thin sections were just too much, and I wouldn’t get the alloy to flow in them. However, I have recently come across some quite amazing silver paint which gives one of the most realistic ‘chrome’ finishes I’ve seen.

To be honest it’s not actually paint at all. It’s an ink. Molotow make some Liquid Chrome pens which are themselves quite stunning, and they provide refills for them. The refill ink is easily airbrushable straight from the bottle.

The other major activity I have finally embarked upon is the sanding down of the hull. This is a task that I dislike, quite a bit, but is a vital part of boat building so has to be done. I also have to do it in batches because of the noise it makes, and I don’t get on with noise at all. It’s a slow process but is about 50% done now. Once it’s done that way will be clear to start staining and varnishing the model.

1:8, Boats

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

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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.

1:8, Boats

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

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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)

1:8, Boats

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

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Having shelved the Chris Craft build for the time being until I can locate some acceptable fittings, or am well enough to make my own, I decided to move on to another boat build.

The model chosen was another 1/8th scale model. This time of a 1922 Gold Cup race boat derived design called Miss Severn. The kit is produced by Mack Products, and mine included the add-on lighting set. As the model will be built for static display, none of the radio control elements  will be fitted.

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