Article: Pocher K74 Mercedes Benz Spezial Cabrio A rebuild

[CTDavies]

Hello Everyone,
new guy here, Chris from Germany. First a little bit about myself; I am 50 years old, work as a freelancing architect, I'm married and have a daughter who's now 12 years old. I've been building models all my life, and in the last 20 or so years I focused mainly on RC scale airplanes. I tried my hands on a Pocher Mercedes when I was a teenager but failed miserably, so this here is my second attempt (actually it's my third - but more on that later). I have been looking for something other than RC airplanes for a while and started looking around on ebay for a Pocher project to try out without spending an enormous amount on a mint kit, that I'd would probably ruin in the process.
So here it is: I was able to purchase a started Mercedes for a reasonable price a few months ago, that was in desparate need of some TLC, which looked like the right project for me.

[Andym]

You've come to the right place Chris. Lots of great folks and fine model builders here and we're all willing to share what we know. Don't hesitate to ask questions and post pics of your progress as you go.

If you are looking for any reference photographs of the 1:1 500K just let me know.

Welcome to SMC.

Andy.

[CTDavies]

The previous owner obviously had a cat (or probably even more) as the the parts were full of brown hair and everything needed to be cleaned before I could start.
I eventually started on the engine, taking it all apart again, to start as in the instruction booklet with the crankshaft. No parts were painted, which made life much easier for me, as after washing the parts with a mild detergent, I could spray paint everything with my air brush.
The crankshaft parts were glued together making segments where some filler was used the clean up the joints (the white stuff on the images). After that all the segments were airbrushed using a glossy black enamel .

[CTDavies]

Hi Andy,
thanks for your kind welcome, always appreciated. I have the Paul Koo DVDs and both Melin books, so I'm pretty much set with reference material. What I would love to see is more images of the actualy prototype Pocher used for their model, which, apparently, is locked away in some vault in Turin and hasn't been seen for decades. This is a picture I found on the net of which, I believe, is the prototype.

[CTDavies]

For the engine I used these two images from the Melin Book Volume 2 which are probably from the owner's handbook. Although they are black and white monochrome they still give a good idea of the colours of the components.

[CTDavies]

Although none of the following will be visible later, I still decided to paint the pistons and connecting rods, because me knowing that a good job was done is reason enough to do it. Everything was done using Testors Metalizer although I don't see much reason not to use a regular enamel . The advantage with metalizers is, you get more choices in metal types and shades. For the con rods I used Burnt Metal and for the pistons Aluminium. But, boy, that stuff goes through the airbrush like nobody's business and I'm already going to have to stock up again on the Aluminium after one weekend.

[CTDavies]

I'm not sure if the top of the pistons would have been matt black as I did them, but I thought it would add some extra detail. Maybe the oil content in the fuel was too high. After the paint had dried on the crankshaft parts, everthing could be assembled again. Next time I might mask off the journals first because the extra thickness of the paint now makes everything a little bit stiffer and the whole crankshaft doesn't turn very easily.

[CTDavies]

My intention with this project is to try and make the best with what's available, hoping I'll succeed. I've seen amazing online build of Pocher kits, where nearly everything was replaced with handmade brass parts, closer to the original than the Pocher parts, well I don't have a lathe (yet) so I'm going to have to stick with what's supplied.
The next step was cleaning up the engine block and crankcase. A lot of parts suffer from ejector marks, mould lines and even defects after usage for many years. So armed with various grades of sandpaper, filler and primer I cleaned up these parts as good as I could. On the few colour images I've seen of the engines, I noticed that on a lot of them, the colour of the engine block matches the colour of the car, so with mine going to be black, as on that previous image, it was an easy choice. But it had to be glossy again, only this time I used a spray can from the hardware store, which dries very hard and very quickly. I had to be careful not to apply too much paint, which easliy happens using a spray can.

[Andym]

Here are some nice 500K shots that represent the same chassis and body design as the Pocher 500K.

[CTDavies]

All other engine parts needed at least some degree of cleaning up. The moulds were sometimes damaged and scratched which showed up on the parts, so again, armed with sandpaper and primer I set about getting these parts done to a reasonable standard. I started with those parts I would paint in a semi gloss black, the long air filter, the starter and the generator. The air filter is connected to the supercharger manifold, but the stub for this was moulded very badly, so I replaced it with a short piece of music wire.