More painting

Painting

Finished polishing the wings and started painting them. Finished with the gray, and continued with orange. Started painting the trim on the fuselage also,

Fuselage and horizontal stab

The horizontal stab is no finished. Polished alu and orange on the upside and gray and orange on the under side. Painted the fuselage on the underside.

Orange on the horizontal tail

Orange on the leading edge, in the same manner as the vertical tail. The wings will also have these colors. The vertical tail, as well as the wings have gray paint (RAL 7035) on the underside to better withstand the dirt and mud. The over-side is polished aluminium and orange (RAL 2000).

Paint

Painted the underside of the elevator and horizontal stab.

Painting

On the underside of the fuselage, tail and mid wing, there will be light gray (RAL 7035). Started painting the flaps and the lower part of the rudder.

Polishing and paint

The vertical fin painted, and started polishing the fuselage.

Painting vertical fin

Using 3 in 1 and painting the vertical fin yellow-orange, or RAL 2000 to be more specific. The whole plane will be a mix of polished alu, orange and grey.

The Power Coat 3 in 1 is an industrial paint based on modified polyester. I have used it for several things, and it is equally strong as the polyurethane I used in the cockpit. Really easy to use, and the surface is matt-ish.   

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.

Right wing skeleton finished

Finished the right wing spars and ribs, riveted and bolted together ready for fitting of the skin.

Tried to spray on the Jotun Topgloss BR (Polysiloxane) with a new and much better spray gun. The result was very bad. If it is me who is terrible at spraying, or that the paint is not formulated for spraying, I don't know, probably both. It was full of pin holes or fish eyes (I really don't know the difference), looked awful even where no pinholes were seen. But I rubbed the half of the test piece with Biltema rubbing again, and it was all shiny again. Have to get some Biltema Hard Wax tomorrow and see if also that makes it all milky like the two other waxes I tried.

The 3 in 1 paint is very good. It dries in 10-15 minutes, but then it is rather soft. After 3-4 days it gets all hard and nice. J. S. Cock also has a special primer for aluminium. It is the same stuff as this 3 in one, but specially formulated to stick on very smooth surfaces, aluminium and stainless steel in particular but also glass. It is only on larger cans, not rattle cans.

I have this booklet "How to paint your own airplane" by EAA. What a total waste of paper! All it say is Acid etch, Alodine, epoxy primer and polyurethane top coat. Yes, it works and the result will be top, but the problem is that: 1- Acid etch will creep into joints and corrode your airplane from the inside. 2- disposing used Alodine is almost impossible due to hexavalent chrome. 3- Urethane is poisonous and requires a booth and a breather. 4- Epoxy primer isn't even necessary. Doing all this with all these extremely nasty chemicals is not something to do in your home. A heated garage will work, but the main point is that the only corrosion that will exist on a painted surface of aluminium is filiform corrosion, and to prevent it does not require all these stages. The corrosion that causes most problems is galvanic corrosion, and none of this will do anything to prevent it. Besides, these products are impossible to obtain locally, for me at least.

If I should go for Polyurethane, the process will be scuffing with scotchbrite, etch primer or epoxy primer, topcoat. That will last for ages without any filiform corrosion and the finish will be top. If that was to corrode, it would be due to galvanic corrosion caused by fasteners and similar. This will also require a booth, but it is somewhat doable because I can get the stuff locally. But, the equipment (booth, spray guns, breathers etc) seems like a whole lot of money and time for a one time process, that may turn out bad. Sending the airplane to some professionals may very well be a better solution.

What I (still) hope to do is use this Polysiloxane with paint and roller. Then wet sand with 1000+ grit, Biltema rubbing and wax it. It is only this waxing part that is a problem right now, maybe I can do without waxing? For primer I have four choices; Epoxy, etch primer, Vinyl (Jotun) or Polyester (JSC). Epoxy and Vinyl I know will work, etch primer and polyester I have to try first. All this I can do at home, and the end result will be like polyurethane, in some aspects even better (UV). In the cockpit I will use 3 in 1 rattle cans with a top coat of clear satin enamel, or maybe 3 in 1 spray gun with the special reducer that gives a harder satin finish instead of the matte finish.

The other choice is polish.

Ailerons, primer and top coat

Bought Topgloss BR (Polysiloxane) at COOP along with some rollers and other stash. Then I went to the drug store and got some 60 ml syringes so I can accurately mix smaller amounts of the Topgloss. The syringes were surprisingly inexpensive, 3.5 NOK or about 0.4 Euro a piece.

Finished deburring the cutouts in the ailerons and measured up all the rivets for the ribs. Then I scuffed a test sheet of aluminium to test the Topgloss. I primed half of it with the vinyl primer and left the other half, just to find out how the Topgloss is with primer and without primer. I let it dry until tomorrow. The sheet is actually a faulty piece of RV horizontal stab skin. I really miss my old priming booth when testing all these primers and coating.

I haven't heard anything from Jotun about using Topgloss BR with no primer, so I just have to try it and see how it goes. If this works out, I will coat the whole plane with Topgloss instead of polishing. I'm not too keen on coating the whole plane with this vinyl primer with rattle cans though. If a primer is needed, then my old Monopol wash/etch primer gives a really smooth and thin coat, if it is compatible with Topgloss. But it is also possible to thin out the canned version of the vinyl primer and spray it on with air and achieve the same thickness as the wash primer (30-40 micrometers). Theoretically a 35 micrometer primer covered with a 35 micrometer Topgloss BR gives a total added weight of approximately 2 kg. This weight penalty is nothing when knowing that the polysiloxane is better than any polyurethane out there. In the cockpit I can also use Topgloss BR, hopefully with no primer.

Then the whole plane will be "Pegasus Grey" with tips and cowling in "Draco Red" and maybe with some trimmings in Draco Red as well.

Measured ailerons

Cut the ailerons to correct length and measured up all the internal cutouts and ribs. Also deburred all the ribs and plates.

Changed the color from dark green to bright orange. Dark green is nice, but it's so dark that it only looks good in sun shine. Here in Stjørdal the sun is not something that is shining all too often, and then the airplane will look too dull and dark. With orange tips and cowling, the airplane will look similar in color to the picture of the Trial further down (or ordinary Sonex polished style with orange instead of yellow). I think that will look cool, also on rainy days.

The Duplicolor turned out to be really a turn down. The finish really is nice and shining, but there is too little pigment in there. It is literally impossible to cover anything if the prepped surface is anything but white, and when the Duplicolor plastic primer is transparent, there is a problem . The tip that was partially green is impossible to get orange, and the seems in the glass fiber (dark color) shines through. I am also skeptical about duplicolor aluminium primer. I tried to sand it, and it goes off in a couple of wipes. The Jotun Yacht vinyl primer on the other hand, is 10 times as durable and can be sanded to a smooth finish. I also tried the houshold "Quick spray" primer from Scanox, it is much more durable than the Duplicolor. At least the Duralac works really well, and that is the most important thing. The Jotun Vinyl primer can be put on anything, and it can be covered with 2k paint.

I put the dimple die in the drill and sanded it to #31 size, it took ages. On the rudder about 1/3 of the stems had to be sanded a bit. From now on all countersunk skins will be #31.

Dimpled the H-stab

Dimpled the H-stab. Match drilled the rudder. Now I have to wait for Lasse (the controller) before I rivet the skin onto the skeleton.

I also tried the Duplicolor spray on the tip. It looked nice. The color is dark green. The process will be to use Duplicolor plastic primer on the fiberglass parts and Duplicolor aluminium primer on any aluminium parts I want to paint. Then on top I will use Duplicolor 2K clear paint. This should look nice and be very durable.

I saw on the EAA webinar that some actually use Latex paint. I think Latex paint in the USA is the same as we call acrylic waterbased paint?, normal house paint. It looked very interesting, but I think I will stick to Duplocolor car paint, or else I would have to experiment a whole bunch to find good Latex paint here in Norway.