A sample kit of Oratex UL600 from Lars at betteraircraftfabric.com is my first real look at covering Goat. I watched a good bit of youtube looking at covering techniques of Oratex, but in the end, it's just like model airplane covering. It couldn't be any more similar, with the exception that you paint the adhesive onto the fabric and structure instead of it coming pre-applied. Once dry, an iron sticks the fabric onto the structure, and a heat gun pulls out any wrinkles in the open bay panel. Very straight-forward.
The sample of white that Lars from betteraircraftfabric looks a lot more pigmented than the "natural white" color. I suppose if you were painting, it would be fine with natural, but the pigmented white looks much nicer to me.
Boy UL600 is thin. Not entirely sure what I was expecting in the fabric. Maybe something more akin to a Dacron hang glider leading edge? That stuff is stiff. UL600 is thin and light, by comparison. That makes sense given it'll take somewhere around 40 sqyd of fabric for Goat (rough estimate). At 3.24 oz/sqyd coated (per the datasheet), that's about 8 pounds of fabric weight. Adding glues and tapes will be a few more pounds I guess.
I tried to stick a finger through the covering sample and it has some resistance, but just flexes and doesn't break. A coworker of mine has a maule tester that will be interesting to see used on this test piece.
For surface prep, I went over the aluminum with a green scotchbrite pad, which definitely removes the shine and leaves a haze with a visible brushed look. I just wiped this with a clean cloth, but had a couple spots that seemed to fisheye when applying the adhesive. Not sure if this was insufficient scuffing or insufficient cleaning. Next time I'll use a wipe with isopropyl to make sure any finger greases or dust is removed.
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