Thursday, October 30, 2014

MFH's 908/03: Paint and other progress, sort of

Prior to leaving for a week-long business trip, I decided to respray the 908 body panels with Testor's light blue, which I think is closer to the classic Gulf Oil blue. It's still a bit of a slate grey shade compared to the digital pictures I have, which show a pale blue with little grey,  but in the absence of an airbrush, it will have to do. (MFH recommends 9 parts sky blue to 1 part white). There will be plenty of time to revisit this as I don't see body panels coming together anytime soon.

I also made some progress on the dashboard, although this was a bit of a comedy of errors. One of the 4 clear plastic divots that serve as warning lights pinged out of my tweezers and got eaten by Mr. Carpet, while the larger of the decals for the dials cracked and split. The missing warning light is immediately visible, while you have to squint to see the problem with the decal. Nonetheless I may dig through the parts bins for substitutes for both items, as the cockpit will be quite visible.

On my return, family activities kept me busy for most of the week, and not much more has been accomplished. And since I am going away on business again next week, I suspect it will be a while yet before anything further gets done. Stay tuned...

Originally posted 30 October 2014

Saturday, October 18, 2014

Ever wonder where polystyrene comes from?

Recently I come across information about the styrene monomer from which polystyrene is made. It turns out that styrene, like almost everything in the petrochemical industry, comes from a mix of ethylene, which comes from ethane, and benzene, which comes from hexane. And ethane and hexane both come from petroleum. Let's look at each in turn.

Ethane is a simple hydrocarbon with 2 carbons and a full slate of 8 hydrogen atoms:

The picture illustrates carbon's gregarious nature; it likes to have 4 friends. Hydrogen is a little more stand-offish and really only wants one friend. So ethane has two carbons, each of which has three hydrogen atoms and the other carbon atom as friends. Chemists write this as C2H6.

However it turns out that you can't do much with ethane as it stands, except maybe mix it with propane (C3H8) to make a fuel for the barbeque (which is of course an excellent thing to use it for, and which therefore merits it a mention as one of my favourite molecules, especially when accompanied by an ethanol-enhanced beverage). But if we take advantage of the fact that carbon can decide to be really, really BFF with another carbon atom and make what is called a double bond, we can strip off two of the hydrogen atoms in ethane to make ethylene, C2H4:

Here each carbon has two hydrogen friends, and the remaining two friends are taken care of through the BFF, double-bond relation with the other carbon, which counts for two friends.

Next is hexane. If ethane consists of two carbon atoms and a full complement of hydrogen, hexane consists of six carbon atoms and the usual full complement of hydrogen atoms, in this case fourteen (C6H14):

Now comes the really interesting part. It turns out that you can bend hexane around into a hexagon, creating three double bonds and eliminating most of the hydrogen atoms, thusly:

You will note that each carbon atom has four connections: one to a hydrogen atom, one to a carbon atom, and two to a second carbon atom (its BFF). This molecule is known as benzene, C6H6. Now drawing this is a complicated business, and some smart fellow (probably an engineer, being busy people they like shortcuts) decided that you could represent the benzene ring much more simply, thusly:

Now here comes the fun part: by replacing one of the hydrogen atoms around the ring with a link to an ethylene molecule, you get ethenyl-benzene, a.k.a. the styrene monomer (C8H8):

Now I have brought up the word "monomer", which means one ('mono') unit ('mer'); string a bunch of these together and you get a polymer, in this case polystyrene which is made up of a large number of styrene monomer units.

So there you go: from black gooey crude to a clear, hard plastic material that melts at fairly high temperatures and that has excellent stiffness and hardness while being easy to mold or shape into all kinds of interesting things, like for instance a 1/24 scale model of the Mini that won the Monte Carlo Rallye in 1967, driven by Paddy Hopkirk.

Originally posted 18 October 2014, update 21 January 2015

Monday, October 13, 2014

MFH's 908/03: Front frame assembly

I took the holiday Monday as an opportunity to make some progress, again with the goal of having some success stories as a morale-booster.

The front frame, like the structure around the engine, is a bunch of struts and A-frames made of spun-cast white metal, with little dowels meant to fit into equally little sockets. White metal being soft, all of these can easily be bent, after which they will not line up. It is also easy to shear off a dowel if pushing a little too hard. So the trick is to gently get it all to line up dry, then hold it with one hand while dribbling some fast cyanoacrylate glue (3-second Crazy Glue) into the seams. This can be sloppy, and it is critical to have some acetone handy for when you get too much glue in there and either make a big blob, or glue your fingers to each other and/or the model, or both. (Guys, I hate to say this, but the best source of acetone is nail polish remover ... so man up, grit your teeth, and drop by the cosmetics counter of your local drugstore where you should ask for the plain, non-scented variety. They will give you a 250 mL bottle which should last you just about forever, so you won't be needing to do this every week. While you're at it, load up on Q-Tips or cotton swabs so you can control where the acetone actually goes.)

Today's activities included painting and assembling the two brake fluid bottles and the fire extinguisher. I did not have the heart to try making brake fluid hoses connecting the bottles to the master cylinders which were installed last winter; even with my 4X desk glass, this is getting into detail that I really can't make out very well.

Following that, I installed the four remaining structural components of the front frame, along with the rack & pinion and front anti-roll bar. Last came the oil cooler and hoses running under the passenger seat to the rear. The picture shows the front frame, floor pan and engine, with the seat loosely in position, but this is just for show, they are far from being ready to glue together.

Next: inner fenders and dashboard, steering and front suspension, and cockpit bits like the battery, ignition coils and sundry other little gubbinses  prior to attaching this all to the engine and rear frame assembly. The instruction sheet has 28 steps; I've completed Steps 1 and 2 (front frame), and most of 8 through 13 (engine, transmission and rear frame), so I'm at maybe 30% complete.

Finally I am concerned that the Tamiya blue is just a bit too dark; the last photo shows the Tamiya colour compared with Testor's light blue. I may just respray with Testor's, to be decided; it is not as grey as it looks on screen (or at least on my screen).

Separately there has been some minor progress on the 956 pickup. Clearance for the 956 front wheels requires opening up the front fenders, which will cut into the cabin. I applied a light coat of primer today; once this is dry, sanding and filing to take down the rough spots will begin. The goal is the same Gulf Oil colour scheme as the 908...

Originally posted 13 October 2014

Sunday, October 12, 2014

MFH's Porsche 908/03: time to get started again

I stopped work on the 908 in the spring, partly because the weather was warm and it was time to get out of the house, but also because I was getting frustrated with some of the very fine detail, such as throttle return springs and plug wiring, which are proving to be at the very edge of my modeling skills.

In the photo, you can just see the throttle return spring, dangling from its bracket on the throttle slide at about #3 cylinder. This is particularly frustrating as the spring has the eyelets at both ends in the same plane, but the installation requires them at 90 degrees; as the spring is made of high quality spring steel, I can't just bend it. Alternate solutions will need to be dreamed up.

Not wanting to get stuck at this level, I've decided to do something where progress can be seen in a hurry: painting the body.

Finding the right blue in a rattle can was the first step. (I don't use an airbrush, because it is an added complexity, although I may wind up changing my mind on this if I ever start spending significant amounts of time on modeling, i.e. when I retire). Testor's has two shades of blue, one which strikes me as too dark (1211, the colour I used for the Alpine A110) and the other too light (1208), while Tamiya's TS-23 seems just right. Accordingly I started with two light coats of Tamiya primer which went on nice and smooth, followed by two of the blue. Right now it looks a little bold (the Gulf blue was probably diluted with a bit of white), but we'll see as it dries. Certainly the finish looks good, no orange peel or runs.

 The usual patience is now required while this all hardens, say a week. Meanwhile I dug out all the bits for the front subframe and began getting reacquainted with them. This led to a long session with the #70 drill to clear out some of the socket joints, which will be followed by a session with the nail files to sharpen up the dowels that are supposed to fit in these sockets. There is also a fair bit of scarf on the various tubes to be cleaned up, as the spun-cast white metal moulds are not perfect. (Of course most of this is only visible with my desk-stand 4X magnifying glass). Zen, baby, Zen ... all this to ensure that the crazy glue will flow nicely into the various joints, and that subsequent components will fit.

Originally posted 12 October 2014

Wednesday, October 1, 2014

There are models and then there are Models...MFH Porsche 908/03

In August 2013 I ordered a 1/24 scale kit of the Porsche 908/03, in the 1970 Targa Florio winning #12 livery driven by Brian Redman and Jo Siffert.
The kit was provided by the Japanese firm Model Factory Hiro and sold in North America by Island Collectibles, There were several reasons for laying out the money for this: 
  • I’ll want to start building it when I retire;
  • It will be unavailable by then and I will be kicking myself for not ordering it sooner;
  • It’s a proper little go-cart, enhanced by the 3-litre F1-based 4-cam flat 8, and belongs in every collection.
There are probably more kits out there than 1:1 cars, Porsche having built fewer than 20 of them. It seems Jerry Seinfeld owns the 1:1 Redman/Siffert car ... here’s hoping he's looking after it. Kit details here:

So anyway I will get around to completing the 956 pickup and sundry other styrene kits as outlined in previous posts, and I certainly intend to tackle the range of resin kits sitting on the shelf, but I would like to make some progress on the 908 over the coming winter. As a starting point, this blog entry summarizes the work to date and thus the starting point for work beginning this fall.
First impression on taking delivery of the kit in mid-September 2013 was the large number of bits, many of them spun-cast white metal, none of them with any identifying labels. Sorting out the little baggies was time consuming, getting suspension bits in one bin and chassis bits in another. There is tremendous detail here, and clearly lots of fine work will be required to make the bits all fit, unlike Tamiya or AMT styrene kits where it's almost paint-by-numbers.

Interesting that the car is about the same size as a Lotus 7 ... the 380 PS motor in the 908/03 is, however, somewhat hairier than the Cortina 1.6 litre pushrod unit, even though the latter puts out something like 90 HP with its pair of Webers.

I tackled the engine first. This began with 3 hours spent drilling out holes in the cylinder heads for oil drain pipes from the upper (inlet) cam box to the lower (exhaust) cam box and thence back to the sump. These drain pipes were to be made from 5 mm lengths of 0.5 mm wire (supplied). More drilling was required for 0.4 mm spark plug wires (they are twin plug heads, so 16 plugs) and matching holes in the distributor, all using my pin vise and number drills in the #74 to #78 range. I can see that the distributor wiring will be challenging... I am also impressed at how flexible a #78 drill (0.016” or 0.4 mm diameter) can be without breaking.
Another two hours was spent cleaning up part lines and various doweled joints around the engine. Following this I glued up the crankcase and the left and right cylinder banks. 

Separately the floor pan, gas tank pods and forward subframe came together. The photo shows a typical Porsche floor-mounted pedal assembly and two hydraulic cylinders, all bolted to an aluminum tube frame with fibreglass floor pan. Given what I have seen of early 911s, I assume these are both brake cylinders, with the clutch being cable-operated. Space frame components to be added next will include a pair of hydraulic fluid cylinders and the associated tubing. I won’t identify the spots where I have screwed up, up to you to find them.


Two steps forward, one back ... Next I assembled the fan shroud and air intake systems. The kit did not include belts for the fan or alternator, so I scratch-built these. I drilled the holes in the stacks for the injectors, and started getting myself ready, psychologically, for the challenge of wiring up the distributor. Unfortunately, while trying to clean up accumulated paint in the spark plug holes, I broke my #78 drill bit in one of said holes. The bit being hardened steel, and the head being white metal, it seemed it was pretty well stuck there. However, using a tapered diamond tip bit in the Dremel to put a slight dish in the end of the broken bit, I was able to push the bit further into the head with the tip of my awl. (Good thing I had originally drilled all the plug holes clean through the heads). So there should now be room to poke the plug wire through. 
Of course this meant identifying a supplier of #78 bits, as most suppliers provide this as part of a set of drills from #80 to #61. Micro-Mark came to the rescue here:

I can also whine about how the regular handling means paint is getting rubbed off, especially at sharp edges, but even with the screw-ups, this is one of my better efforts to date, and the mistakes are really only visible with the 4X magnifying glass. Again I will award major brownie points if you can identify the worst screw-ups.

Next I put on the oil filter, an unidentified gubbins driven off the rear of the left side inlet camshaft, the fuel injection pump, an oil feed tube from said oil filter to said injection pump, and the 8 velocity stacks. I assembling and painted the spaghetti-maze of the exhaust system (it's set up as a pair of flat-4's end-to-end, is this the last vestige of the VW heritage?), and drilled and tapped the M1.4x0.30 hole in the front cover that will take one of the screws holding the motor to the chassis.

And this is where things ground to a halt, in early January 2014. I spent some time in February and March 2014 moving furniture and hammering on nails, and discovered that while these activities improved my core strength, they destroyed the fine motor skills necessary for this level of modeling. Then spring came along and I got the bike out ... see my separate blog on this topic.
Meanwhile I ordered a kit of the fearsome 1970 Porsche 917K from the same supplier, also because I didn't want it to be sold out when I finally get around to building it. If the 908/03, with its 3-litre flat 8, was the weapon of choice on twisty tracks such as the Targa Florio or Nurburgring, the 917, with its monster 4.5 litre flat 12, was well suited to high-speed tracks like Daytona or Le Mans. The next generation of Le Mans cars, culminating in the unbeatable 956 and 962, involved plenty of aero bits; the 908 and 917 were the last of the old-school racers built with little or no understanding of the importance of an aero undertray, and the drivers of these cars were certainly heroes in taking these little hot rods out on to the Mulsanne at 250+ k/h with all that front end lift. Ooof -- I know I'd be lifting off across that little hump on the Mulsanne.
The version I ordered replicates the 917K as driven by Redman and Siffert,  and which also now belongs to Seinfeld ... clearly he has good taste in classic cars. Redman and Siffert didn’t win Le Mans in 1970 (a 917 operated by the Salzburg AG team won), but the car carries the same classic Gulf Oil colours as their Targa Florio-winning 908/03, so there is a link between the two cars.
Stay tuned as the cooler weather starts and the opportunities to get out and ride the bike become fewer.
Originally posted 1 October 2014