Painting the engine take 2

Painted the engine - again. This time with a more suitable and stronger paint in the color RAL 9006.

Painting the engine

Found out the "barbecue black" is dissolved by gasoline, and any other solvent. There will be no way to clean it when the paint dissolves. Maybe it will cure when warmed, but that requires at least 200 deg C. The engine casing does not get hotter than 100-120 degrees. The Power Coat 3 in 1 I have been used before takes 200 deg, and the RAL 9006 (aluminium color) takes 250 degrees, so I bought one can. The black went right off with silicone remover, but all the holes and corner was some work. Clean enough for a coat of powercoat.

All this paint stuff has been a real pain a certain place. This Power Coat is good though. The only bad thing is it cant be covered with PU. But now that I have decided to polish the plane, the whole PU "problem" is gone.

The Power Coat gives this satin/matte shine. I will use that for some trimming on the polished skin. That should look cool I think, and it's easy to use.

Engine painted, and tail wheel solved

Painted the engine "barbecue black" with real barbecue paint. It came out really cool even though the black is almost stealthy black. I will paint the cylinders with the same paint.

On Sonexbuilders I got the all too obvious solution to the tail wheel problem. Turn the brackets around! (why didn't I think about that??) This will move the bolt holes about 10 mm up, which is just fine. With the brackets turned around, the angle also became right, according to drawings.

Tail wheel

The tail wheel mount need some modifications to get the bolt in there. The space is too small and the bolt is too far down and too long. I don't want to cut too much into the main structure. Seems there are two options.

1. Make a bolt with thread on both sides. This will be able to slip in from the side more easily
2. Make new angles with the hole further up.

I have to think some more about this, and ask what others have done. Maybe there are some much better solutions out there.

 
The engine paint. I have no idea what kind of paint stick on magnesium. All the paint available are made for cast iron, aluminium at most. Nothing really stick on aluminium without at least an etch primer, and then the primer also have to be heat resistant. VW did not paint the engines. "Barbecue Black" from the local home ware store therefore seems to be the best option after all.

Engine painting

Washed and cleaned the engine and masked off all open and machined places.

I also planned to paint it today using Auto-K engine paint. According to the web page at Mekonomen the paint is supposed to withstand 200 deg C, which should be more than enough for the casing, and I went down and bought 2 cans. But, I couldn't find any technical data sheet for that particular paint, and that was odd. The German site for the producer of the paint has a different paint, different part number, and didn't even have this "engine paint". Did some more research and found that Hagmans is the producer of "my" engine paint. According to the technical sheet there, the paint is only rated to 100-120 deg C, not 200 deg C. This is really annoying, paint is different and produced by different producers depending on where you live !!! Hagmans is a reputable brand, but "engine paint" reaching only 100 deg C ? I find this very strange, when the "original" paint from Auto-K is 300 deg C, and where does this faulty 200 deg C come from?

Now I'm not sure what kind of paint I will get. "Barbecue black", the "brand" Sonex themselves are using, is readily available, but I'm not too found of flat black, everything just becomes too dark too see. Biltema has some OK engine paint apparently, but is it really any good?

Paint is a real pain, more often than not. So far I have found and used two paint related things that works very well:

Silicone remover from Würth and Acid #8 from U-Pol (etch primer). They just work and the result is first class. I have ordered some boxes with gray 2K polyurethane to put inside the cockpit, I hope it works out well. I will find out during the next few days. This paint is industrial PU paint that Norbond fills up in rattle cans just before shipping. They must be used before 3-4 weeks.

Painting the outside of the AC is something I just have to start planning. My experimenting with rolling polysiloxane didn't really work out, impossible to get a smooth finish, and the polysiloxane cannot be polished (it gets white/flat and ugly). But now I have read about hobby car painters getting good results with Biltema polyurethane boat paint, spray and also with rollers. I have to try that, polyurethane sure can be buffed and polished, and I have heard nothing but good tales from boat owners using Biltema PU (even if some of their other paint is less than optimal).

The AeroVee engine parts made me scratch my head in disbelief today. The manifold enters the engine in two square channels. The engine on the other hand has two round channels. Why? this is simply unbelievable.