Oratex thread

[svyolo]

I am using Stewarts Systems Federal yellow painting metal stuff. I really didn't like the way glossy looked next to Oratex, and it is going to look many different ways of wrong depending on the light. So I tried to get a look I liked. I bought some Stewarts flattener, which helped, but it wasn't flat enough, even mixed to the max.

I tried a couple of different types of "texture" i.e. orange peel. I ended up settling on max flattener, and thinning the paint slightly thinner than recommended. I apply fog coats only until color saturation. When you apply it, it looks like heavy orange peel, but because of how thin it is, it gets mostly settles out. I would call it very fine orange peel. The dull sheen it has looks very similar the the Oratex, indoors and outdoors in direct sunlight.

[svyolo]

I am covering the last control surface, but still have to do all the rib stitching. As I have worked with Oratex, I have liked it less and less. I like the finished product, and the light weight, but I think it takes MORE time and labor, not less.

The support from the dealer in Alaska is very good. The biggest problem, is technical documentation. I would have given it a D- like Colby in his videos until I started the flaps and ailerons. On aluminum structure, the documention is a complete fail. Covering steel tube structures was a bit finicky, but OK. Covering thin aluminum is a whole new ball game, and could easily result in a completely un-airworthy finished product. I am confident the procedure I used has resulted in an airworthy product, but that procedure is spelled out absolutely nowhere in the factory instructions, or the supplement from Betteraircraftfabric in Alaska. I came up with it myself. If you watch Colby's videos, he is almost always doing it with 2 people, sometimes 3. I did it alone, thinking the whole time I needed another hand or four. Occassionally 8 or 10.

A couple of years ago the only yolutube stuff was from the factory. It was below snakeoil salesman quality, and you would have ruined large pieces of fabric in the process. The dealer in Alaska has made some rudimentary videos on youtube since then, too late for me, but still a bit sparse. But better than the factory sales videos by far.

Because my butt will be in the airplane, I thought the process through and was very careful. The correct installation process is so tedious, if I was going to do it a second time, I would trust no one else to do it correctly. But I don't think there will be a second time for me.

I like the finished product, and the weight savings. The rest, for me, is negative.

[Bcone1381]

Thank you for your truth and honesty. We often get silence in the EAB world when something is less than..... Honest data is foundational for knowledge, wisdom, good workmanship and industry best practices.

[svyolo]

As a follow up, the biggest problem I had by far was the ailerons and flaps, which I thought would have been the easiest. I knew I would need to use more heat on the aluminum to activate the glue (>195F for at least 10 seconds) On steel, I used a heat gun set at 250-280F. I tried it on interior parts of the ailerons. 300F didn't do it. 350 didn't do it. I had to use 380-440F to get a reliable bond. I thought my heat gun was bad but it check out OK. The problem was the very rapid heat transfer of the aluminum. I was expecting it. The biggest issue with this is if you are heating the panel very hot, the whole panel gets hot. If you had previously activated glue under, or near what you are activating, and it gets above 290F for several seconds, the previous glue is destroyed.

There is no explanation of this, or techniques to avoid in either the original factory manual, or the one they made at Betteraircraftfabric. I tried to use the minimum heat to activate the glue, and the overlapping areas, I activated both layers at the same time.

[Hewko]

I had originally though I would use Oratex, but then found out about Hipec. It's a Canadian product, available from Edmonton, has been around for a while and is light and inexpensive.

[gregc]

Hipec looks interesting. I just emailed and asked to download a copy of the installation manual.

[Steve W]

I understand tempered aluminum doesn’t like temps above 200*F. When repairing or removing the bottom skin stiffeners that are bonded on Whipline floats, its says not to exceed that temp. Probably for protection of the paint? Correct me if I’m off base here but is the final treatment temp for T-3 around 400*?

[svyolo]

It gets complicated. When I dial 440F into a heat gun, that doesn't mean I am heating anything up to 440F. I am 3-5 inches away. I am trying to get the glue above 195-210F, while the aluminum is transferring heat away as fast as it can. There is a temp gradiant from the surface of the cloth, to the metal. The glue is above the very thin primer, but below the cloth. I do know you can de-heat condition aluminum at a fairly low temp, but I think I am way below that with Oratex. My upper limit is 295F, and that is what I am trying to stay below. What I didn't know is that I would have to experiment myself to try to figure out how to get a temp gradient between 200-295F, over the thickness of .03 inches or so. With no instructions on how to do so. With heavily primered steel, it was no problem. With thin, and very thinly primer-ed aluminum, I could have used a few tips. Instead, I had to experiment to get it right.