STI Farm Fox Build Log

[Kitfox Pilot]

Its up to the builder to or not to some do, I chose not to. Mine are all glued so shouldn't be any wear.

[Kitfox Pilot]

Looks good! That should help with the exhaust stains. Unfortunately the stains do come up the side with the prop wash/slip stream. Gear legs get stained also.

Yes I knew it would but I'm wanting to make sure my tightening job is good before I do any more and I will tone down the shine if I put it on the side.

[Shadowrider]

Oratex says if it touches you glue it. Only places you run finishing tape are on seams of two sections of fabrics. Even there you have the option if the overlap is big enough. Oratex stresses not to follow anything prior or "other" manufacturers instructions as their system are completely different. If you want to add finishing tapes for looks you can but it is not needed.

[alexM]

I think the most amusing part about Oratex is the way it blows everyone's mind how differently it is applied.

[efwd]

Of interest to me is how Dustin suffered the exhaust deposit problem. His stained yellow if I recall correctly but my experience has been different. I have a dusting of exhaust as if the engine was coughing up a bit of baby powder. It does deposit at least halfway down the airframe, including the side beneath the pilot door. Mine wipes off nearly effortlessly and no stain. Possibly a different fuel formulation? I use 100LL exclusively.

[Eric Page]

Are you using Decalin Runup? I'm no chemist, but I presume that stuff binds with the lead and carries it out the exhaust. That might be the powdery deposits you're seeing.

[Shadowrider]

Oratex told me, and it made sense to me, they think the difference is the turbo. Turbo engines leaves more stains. Because the exhaust gases are much hotter and they burn a little more oil, and the turbine housing also spits of some oxides when hot. They build rust and soot until you get them hot again. All that combined causes more staining than a normally aspirated engine.

[efwd]

From Decalin Chemicals

"Some white deposits may be seen on the plugs and in the exhaust pipe during use; this is normal with RunUp since the lead in the fuel is being converted to non conductive lead phosphate. When no additive is used, lead oxide is formed. It is lead oxide which causes plugs to misfire due to its partial conductivity shorting out the plug. In addition, lead oxide tends to form in large clumps or clinkers whereas the lead phosphate is crumbly and if any is left behind in the combustion chamber it deposits in even layers."

[jrevens]

Oratex says if it touches you glue it. Only places you run finishing tape are on seams of two sections of fabrics. Even there you have the option if the overlap is big enough. Oratex stresses not to follow anything prior or "other" manufacturers instructions as their system are completely different. If you want to add finishing tapes for looks you can but it is not needed.

Interesting discussion about the Oratex. I was one of the very first users, and finish tape was definitely “required” at that time. There was also no talk about gluing to anything that it touched. I don’t know if not using it is the position of the company itself now, or if that is strictly the opinion of Lars, the dealer in Alaska. Finish tape is one of those time & experience proven things based on fabric covering systems that don’t necessarily apply with something different like Oratex. There are many things that are done in “approved” ways when building an airplane that are not necessarily “needed”. There is also advantage in selling a product if you can make it quicker and easier to use & install. It will probably take many years of field experience to determine with certainty that there is no need to copy what has been the recognized standard with other cloth covering systems, but that’s just my opinion.

[Shadowrider]

John, I think there where users years before you using oratex. I would not recommend installing polyfiber after reading the oratex manual, and I would not recommend installing oratex after reading the polyfiber manual. I went off of the opinions of those that have installed it and had experience with the product and not first time users.