My recent fabric job

[Guest]

Re: My recent fabric job

Just to be clear and I updated my last post I had been saying the "I simply would not have used it" and my meaning is that I would not have used the auto gas.

I would still have used Stewarts but would not have used auto gas. I have been using auto gas for a long time but can used avgas, I just didn't know that I should (until know that it is too late).

I think that I did not make that clear enough before so s I just said I changed my prior post to make it more clear.

Dave R

[PA1195]

Re: My recent fabric job

And from my Post#31: "Autofuel or a blend of that and 100LL is a reality for some owners. Having a covering that's potentially subject to compromise from that fuel would be a non-starter for me."

Gary

[Guest]

Re: My recent fabric job

And from my Post#31: "Autofuel or a blend of that and 100LL is a reality for some owners. Having a covering that's potentially subject to compromise from that fuel would be a non-starter for me."

Gary

yep, got it

[N96337]

Re: My recent fabric job

How do you do that with envelopes? or with the tank installed in the bay with the drag, anti-drag wires installed and going thru the tank, makes no sense John, what am I missing?

You're correct...no way to do that with an envelope, or the tank installed. I used an envelope once, long ago, but haven't since, so to be honest that never even entered my mind Dave. I've sprayed the interior before setting in the tank...it's a pain, and I haven't done it for a long time, but it's doable.

[Stewart Systems]

Re: My recent fabric job

Auto fuel tolerance aside it may be that using a new covering process brings change and risk. We (they actually) tend to forget how many planes and years it took to perfect whatever method. Plus there's lots of peer support available when questions arise for old time processes. This process is relatively new and the environmental safety factor is a plus. If it adapts to cold even the better for some of us.

I wonder if it can be made fuel resistant? Perhaps or perhaps not.

Where does the auto fuel enter the covering? Back, topcoat, or edge material?

I clean Polytone with charcoal lighter fluid when stained with no effect to the topcoat. Isopropyl will eat it. Simple Green barely touches some of the surface dirt. This I learned after forest fire smoke left a resinous coating that only a petro solvent will remove.

Maybe Stewarts is less prone to attracting stuff than Polytone. That would be good.

Gary

Gary,

The issue is only on the back side. The topcoat is impervious to auto fuel, lacquer thinner, even MEK. It is a poly urethane similar to solvent borne poly urethanes. If you have to remove it from fabric, sand paper is the only option. EkoFill is a single part product. It holds up just fine to AvGas, and many of the auto fuels, but it is affected by some auto fuel to varying degrees. Often there is little or no effect, but every once in a while it will have a serious effect. But every system is affected by auto gas to some extent. I have poly fiber with Aeothane on my old Stinson and the tapes are peeling under the fuel tank from a previous fuel leak(s). And it does not have an auto gas STC. That's no guarantee that the previous owner didn't use auto fuel, but they shouldn't have been. The nice thing about EkoPoly is that it wears extremely well and cleans very easy. Also, it has more long term flexibility than anything else on the market. Remember, the system was designed for aircraft, so it was formulated to work with aviation fuels, and it does that very well. Someone mentioned that it was not possible to paint the inside of the fabric in some applications. But I would also mention that if the tank it self fails, it's kind of a mute point really. You are cutting the fabric off to fix it anyway, so why does it matter. If you have access to the fuel tank bay, paint the inside, if not it's irrelevant anyway. Test for leaks with avgas to correct any line leaks. It's generally just not an issue.

Andy

[Stewart Systems]

Re: My recent fabric job

Hi Andy, this is Dave's thread so I'll be brief as possible. I've owned nine fabric airplanes, never hangared in Alaska, but none with Stewart's as the primary cover. I've been around a few that acquaintances have redone. All have had issues in isolated spots with delamination or bubbling. I don't know the cause but that may have been due to contamination during build. I have no direct experience with auto fuel and Stewarts.

Autofuel or a blend of that and 100LL is a reality for some owners. Having a covering that's potentially subject to compromise from that fuel would be a non-starter for me. The benefits of durability and lack of cold crack would be a positive aspect. I have a few lower wing inspection rings glued on with the Stewart's glue that's holding well in an experimental test versus the Stits glue.

Never had fuel associated problems with Randolph or ???

Gary

Gary,

In 2012 we had a issue with the EkoPoly topcoat. One of the raw materials manufacturers had an issue with their product and of course it caused an issue in ours. At that time we reformulated the topcoat with newer technology and eliminated that manufacturer from our system. Since then we have had no reports of blisters. To date all of those have come from EkoPoly sold in 2012. We warrantied all the ones we were aware of. It does seem like a lot of those ended up in Alaska for some reason. But that issue no long exists. In that reformulation to EkoPoly Premium we also extended the pot life to 3-5 hours making it much easier to spray and extend the useful shelf life a great deal as well.

Andy

[PA1195]

Re: My recent fabric job

Andy your product support here is welcome and positive. I wondered above if it were possible to alter the underlayment coats to make them more fuel resistant? That would be a good move if it were chemically possible. Is it?

Gary

[Guest]

Re: My recent fabric job

You're correct...no way to do that with an envelope, or the tank installed. I used an envelope once, long ago, but haven't since, so to be honest that never even entered my mind Dave. I've sprayed the interior before setting in the tank...it's a pain, and I haven't done it for a long time, but it's doable.

Tcraft wing tanks and the larger than 5 gallon Aeronca wing tanks have to be set prior to cover because the drag wires go thru the tanks.

So the wings have to have the tanks in to be trammeled.

That means that tanks must be in prior to cover, can't cover then trammel.

The entire discussion seems just impossible on these airplanes, it just doesn't work that way.

Dave R

[N96337]

Re: My recent fabric job

Tcraft wing tanks and the larger than 5 gallon Aeronca wing tanks have to be set prior to cover because the drag wires go thru the tanks.

So the wings have to have the tanks in to be trammeled.

That means that tanks must be in prior to cover, can't cover then trammel.

OH really??? Then how did I pull the tank and repair it and then replace the tank without pulling bottom fabric? Done that a few times. It's not convenient...but it's not that big of a deal.

[N96337]

Re: My recent fabric job

Actually the guy that was giving dave info about not having a standard for testing for autofuel is crap, there is an ASTM for automotive gasoline, I had to read the stupid thing when I was going to get an stc for my fuel valve. I just remember there was something about compatibility of materials, the gasoline needed to be tested to ensure that there were no adverse reactions when used that affected any part of the system. Crap, I may have to look it up...again

Crap, its on my other laptop..

Yes, there is a standard....a quite loose standard for the basic fuel....but it's not the "auto-gas" that screws up things....it's the additives that do that. I've handled millions of gallons of fuel (literally...we've had contracts to move millions of gallons of fuels) and it always sort of tickles me to pull up to the loading rack at the refinery and see Shell, Texaco, Arco, Unocal, and a few other "brand name" fuel trucks filling from the same spout that I do. We used to pull a lot of fuel out of a Conoco refinery, and "rebrand" it for whatever station we were headed for. I remember that when the Texaco "Techrolon" additive came out that cleans your engine as you use it, we had to add about a 2 liter bottle to 10,000 gallons. We were laughing about how this is going to do much good as we poured it in the tank, but the refinery required it and they also required us to be dressed like we were handling neuclear waste just to pour it in. It first came in some HDPE bottles and a carboard box, and that sat in a cabinet on the rack. About 2 weeks after it showed up, the "additive" ate through the bottles. Everything it touched was damaged bigtime!! Paint peeled, corrosion ensued, it was a real mess. They finally went to steel cans and shipped it only like 6 per case instead of 24. My point is, the additives are what causes the problems from what I can tell, not the basic gas. That's why some auto gas doesn't affect paints or whatever, yet the guy the next county over has some really caustic stuff.
John

[Hank Jarrett]

Re: My recent fabric job

I talked to the manager at SFQ about the Auto Fuel they sell and was told it was picked up at the pipeline from the refinery in a truck dedicated to use for auto fuel for aircraft and boat yards ONLY. The fuel terminal for our area says that the pipeline operators will not pump gasoline fuel with ANY additives and all of the fuel retailers must add the "other stuff" in their trucks. They didn't say exactly why, but what John (N96337) said seems to fit in well with what they told our airport manager. He told us there were NO additives in the Auto Fuel the airport sells and he has to do regular tests for alcohol and water on the tank (he didn't mention testing for anything else, but they are SERIOUS about any water or alcohol getting in and contaminating their system). Sounds like a lot of the additives can cause problems for he pipeline operators too. As for the boatyards, they are allowed to sell aviation auto fuel because of all the damage car gas does to marine motors. I guess the Coast Guard was getting tired of towing peoples boats back to shore.

Hank

[PA1195]

Re: My recent fabric job

Typical fuel additives: https://www.goldeagle.com/tips-tools...additive-works

The polyetheramine is what Chevron and Texaco extoll as the best. I've added it annually and it will clean and dissolve carbon if directly applied to spark plugs and allowed to soak.

Gary

[Guest]

Re: My recent fabric job

OH really??? Then how did I pull the tank and repair it and then replace the tank without pulling bottom fabric? Done that a few times. It's not convenient...but it's not that big of a deal.

Sure John, I agree for a repair, the wing has been trammeled already and maybe you do one bay with a trammel bar or put the nuts back exactly where they were, sure I get it. But do we really do that at initial wing assembly? I just don't think its done that way.

maybe we do it different

Dave R

[Guest]

Re: My recent fabric job

Andy your product support here is welcome and positive. I wondered above if it were possible to alter the underlayment coats to make them more fuel resistant? That would be a good move if it were chemically possible. Is it?

Gary

Gary, please don't speak for me when you make make general statements.

Your statement is not correct in my opinion, the support is neither welcome or positive. Its post incident b.s. These people have screwed me over big time by hiding this risk and I am very unhappy about it now they present this erudite b.s. to cover their butt. It is not welcomed by me or positive.

Stewarts and Andy have shown no regard for what may befall their customers by not making the simple warning in their manuals.

A simple warning in their manuals and documents similar to what Andy has made here would have prevented my incident (and probably others).

They are not concerned about the few customers that will experience the auto fuel issues and their own statements posted here make that very clear. One such statement posted here says "The safest thing to do is run AvGas.", wow, would have been great to know that before I put fuel in. Try to find that in the manual, it wasn't in there as late as last week on 5/16/17 in spite of the old issue.

Stewarts manuals have much info and tips and redundant info and not a word about this issue.

So please don't speak for me and tell them that the support is "support here is welcome and positive" because "here" includes me and i don't share that thought.

Dave R

[PA1195]

Re: My recent fabric job

Dave I expressed my opinion not yours. I've had enough of you and your pontificating. That's why discussion in these forums tends to be led by few and others are reluctant to offer comments or opinions regarding their experiences or products.

See you in the next life.

EDIT: Personal message sent to Dave hopefully as reconciliation and mutual understanding.

Gary