Interior covering options — Durability?

[auburntsts]

So I did a search on interior covering options but most of the discussions center on methods and/or weight. Very informative but one missing element seems to be durability/resistance to damage. I know next to nothing about fabric so I’m curious as to what’s the opinions on what’s the best compromise material (ie aluminum, CF, FG, kydex, fabric, etc) when you look at both weight and durability?

[rodsmith]

I'm no expert but aircraft fabric is definetly the lightest unless you go way overboard with coatings. It is surprisingly durable, just keep sharp objects away from it. Impacts with blunt objects will generally leave no marks, even those that can dent aluminum. I don't have any experience with different weights of kydex. Carbon fiber panels are definitely durable but are heavier than fabric and can fracture into sharp splinters in an accident. Aluminum interiors are very heavy, one notable Bearhawk with full aluminum interior weighs over 1700#s. Very durable, but flat aluminum panels are prone to denting if careless with cargo. I would think it would make for a very noisy aircraft. Another consideration, anything other than fabric is going to need some method of attachment to the frame, usually welded tabs.

[Battson]

I have a full fabric interior - lightweight fabric in most places.

Our fabric has withstood seven years of turbulence combined with jostling against bags, packs, rifles, hiking boots, game antlers / horns, spearfishing equipment, dive tanks, skis & poles, snowboards, tripods, wooden things, etc etc etc

Provided you don't load your plane like you load your washing machine, a fabric interior should last 30 years or more (until the fabric reaches end-of-life due to UV).

Fabric interiors are also very easy to repair.

[Rollie]

My last certified plane was a Pacer that had been restored 20 years before I got it. The interior was mostly fabric with a little aluminum in a couple places. The fabric was still in great shape after 20 years and most of the aluminum was good too but a few of the metal pieces were pretty mangled. I was worried about letting my dogs in the back seat area of the plane at first, thinking they would accidentally destroy the fabric interior by bumping/ scraping it with their claws but they didn't hurt anything. Honestly at the very beginning I was thought there might be a possibility they could tear through both the interior and exterior fabric and fall out of the plane. I really didn't know anything about aircraft fabric at that time. It's pretty tough stuff. One of my dogs, a 65 lb Shepard mix, logged about 150 hours in that plane, riding in the back seat area (I removed the back seat almost as soon as I got the plane) and the interior held up fine.

Fabric is easy, at least compared to trying to get a good fit and finish with any other medium, get it to fit ok and then glue it in and shrink it with the iron and it fits perfectly, try that with sheet metal or carbon fiber. And it holds up well. Add in the fact that it's light and it makes the decision pretty simple for a lot of builders. Also, there are quite a few bush planes out there that don't have any interior. Slightly lighter and I suppose it gives you slightly more space inside. It's not for me but plenty of people are happy like that.

And like Battson said, fabric is easy to repair. If you get a cut or tear somehow, clean it up so you can glue a new piece to it, cut a patch with left over fabric, glue it on, iron, paint and it isn't really very noticeable, much less noticable than dented metal or a riveted on sheet metal repair.

[JimParker256]

And if you use Oratex, it's even easier to patch...

[svyolo]

I was going to use about 60% composite panels, and 40% Oratex. I am about to cover the fuselage and I think I will end up with 80% Oratex/20% composite. My composite panels are light, but I can't justify the extra 20 - 25 oz. over Oratex. If fabric is good enough, and lighter, it is good enough for me.

I will still use removable panels near the fuel lines so I can access them for maintenance and inspection. Those are the panels next to the front seats, below the doors.

[auburntsts]

First, thanks for all the responses! At the risk of high jacking my own thread, as I understand it Oratex is the lightest covering option but also the most expensive IIRC. Those two things aside any pros or cons over say Stewart’s? Especially for someone new to fabric?

[Ebkurtz]

The best thing about protecting is you don’t have to paint it. If you don’t paint it’s about equivalent in price to fabric and paint systems. Not to mention the time you save

[rodsmith]

Oratex positives, very light weight and way, way, way less work. Oratex you glue to the frame, heat shrink, apply tapes done. Stewarts you glue to frame, heat shrink, apply tapes, apply a coat of thinned glue to seal the fabric. Spray a cross coat of Ekofill (UV protection), sand, spray another cross coat, sand, maybe another coat. Sand again, spray Ekopoly color coat. None of this is difficult but the quality of the paint job is dependent on how good you are with a spray gun on the color coat. The big Oratex negative of course is the price. Some other negatives I see are limited color selection, colors fade if exposed to much sun, lighter colors are somewhat transparent in sunlight. I used Stewarts, both inside and out. Was very tempted to use Oratex on the interior but was concerned with compatability between the two systems and was bothered by the price. Oratex recommends the heavier fabric for the interior of a bush plane. I did some test panels and found that using less ekofill on the interior fabric, I was only 40% heavier than the heavier Oratex.

[robcaldwell]

I used Stewarts to cover both inside and outside. Since I am building in a garage attached to my home, I could not consider a solvent based system. I am EXTREMELY happy with the results of the Stewarts System, both fabric and paint. If painting with Stewarts, the key to success is 1). use the correct equipment including a high capacity compressor, high flow fittings, decent air dryer, etc. and 2). Follow the instructions in their YouTube videos (both fabric and paint).

[Rollie]

I would have been more inclined to use oratex if the entire airplane was fabric. I don't like painting, well I guess it's all the sanding that I really don't like, but I figured since I was going to have to prep and paint the wings, I might as well do it all. Oratex would be a big time saver. The fact that it is lighter is a bonus. The price, by the time you add in all the paint, primer and, in my case, a better spray gun that would do a decent job with the Stewarts paint, probably isn't that much more. Especially if you put any value at all on the time you spend painting and sanding. I'll probably look closer into oratex on my next build.

[auburntsts]

I would have been more inclined to use oratex if the entire airplane was fabric. I don't like painting, well I guess it's all the sanding that I really don't like, but I figured since I was going to have to prep and paint the wings, I might as well do it all. Oratex would be a big time saver. The fact that it is lighter is a bonus. The price, by the time you add in all the paint, primer and, in my case, a better spray gun that would do a decent job with the Stewarts paint, probably isn't that much more. Especially if you put any value at all on the time you spend painting and sanding. I'll probably look closer into oratex on my next build.

Rollie are you using Stewart’s? I have looked into them extensively when I was researching for a Pietenpol project and used their primer-sealer on my RV-10. I’ve started researching Oratex but need to do some more particularly on matching paint for non-covered aluminum and composite components. Their website doesn’t have much on their paint.

[svyolo]

Stewarts has color code data for Oratex. They will color match exactly($$$) for you or recommend something close. I went with close being good enough. The different texture of Oratex and a glossy paint surface will always make color matching impossible in a lot of different lighting conditions.

[Rollie]

Yes, I used Stewarts.

[Battson]

First, thanks for all the responses! At the risk of high jacking my own thread, as I understand it Oratex is the lightest covering option but also the most expensive IIRC. Those two things aside any pros or cons over say Stewart’s? Especially for someone new to fabric?

I have been told that Oratex is quite fiddly to learn, for some people. No firsthand experience. YMMV.