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About marksires

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  • Location Florida - no more 18 below for me!

marksires's Activity

  1. marksires added a topic in Avidfoxflyers General Hangar   

    Fiberglass fuel tank
    Since this topic comes up occasionally here, I thought I'd post these from the Cozy forum I hang out on.  The Cozy fuel tanks are built into the strakes, no way to do them but fiberglass.
    Joe Person  Jan 21  Per multiple sources (and in general terms), cured epoxy resins have excellent resistance to ethanol (among other things) below 120 Deg. F.  Polyester resins (far-more likely in the boating world)?  Not recommended for many alcohols.   I have a 2-ply BID sample layed up with Saf-T-Poxy & #87 hardener (now EZ-Poxy and EZ-87 hardener), post-cured, and residing in a jar of nasty ol' 87 Octane car gas (with up to 10% ethanol).  Gas is changed a couple of times a year, and this experiment has been going for around 30 YEARS.  No discernable changes in the characteristics of the sample (stiffness, surface feel, etc.) over that time span.   Simply noting that "fiberglass tanks are damaged by alcohol" leaves out a whole bunch of other pertinent information.  Go talk to Gary Hunter, if you need a more scholarly discussion.   -Joe Person - show quoted text - Mark as complete   Phillip Johnson  Jan 21  The problem is that people are still building fuel tanks using incompatible epoxy.  It not in the plans to use Ezpoxy with slow hardener, and many builders are not on this list or join this list after they have completed the fuel tank construction. I built my tanks using Ezpoxy and I still have test coupons submerged in 94 octane fuel from back in the 1990’s.  94 octane has ethanol even in Canada.  That same fuel destroyed my automotive test fuel lines in less than a year whereas my test coupons look no different 20 years later. I use 100% Shell V-power 91 octane in the Cozy and have been doing so for close to ten years with no noticeable effects.  Phillip Johnson (From iPad)Cozy MKIV RG Powered by Subaru IO-200 (SN 0030) - show quoted text - Mark as complete   Joe Person  Jan 21  FWIW, from the ACS website:   Is E-Z Poxy 83 acceptable for use on a composite fuel tank? Is it resistant to ethanol? Yes, our E-Z Poxy line of products are the most fuel resistant epoxy systems we offer. E-Z Poxy has a long history of use in the aviation industry, being originally developed for the Long-EZ kit aircraft. Of the Hardeners, E-Z 83B, 87B and 92B are almost identical with only a slight variation in accelerator to help vary gel time. This series of hardener has undergone long term fuel resistance studies, being exposed to diesel (containing 5% bio diesel), gasoline (containing 10% ethanol) and strain solvents (50/50 isopropyl/xylene blend). The differences in fuel resistance between these 3 should be negligible. E-Z 10A/83B is a great option for integral fuel tanks.   -Joe Person - show quoted text - Mark as complete   Izzy Briggs  Jan 21  So your fuel sample, was it summer or winter blend? What other additives were included? Is it chemically identical to fuel you can buy now? The problem with Auto fuel is that it’s contents are not publicly declared. Kinda like cigarettes or natural GNC supplements or organic gummy bears...ok maybe the bears have the ingredients listed on the package. We are still dealing with MBTE pollution in our wells here in New Hampshire. No doubt your sample and your fuel is holding up. But it’s a stretch to extrapolate those results to all auto fuel blend and all epoxy types.  There’s enough people out there who had problems and had to replace strakes to warrant ongoing caution. Izzy - show quoted text - Mark as complete   Joe Person  Jan 21  My 30-ish year test of auto fuel & Saf-T-Poxy & #87 compatibility has utilized 87 octane auto fuel, sourced (intentionally) from Arco, Shell, Chevron, Exxon, 7-11, Fred Meyer, etc., over the time span noted.  Probably accounts for most of the crappies, light ends, etc. blended into auto fuel.   Yes, YMMV, but, reading the data available over the years, properly mixed, applied, and cured epoxy is quite good against the ravages of ethanol percentages in auto fuel.  As Gary Hunter noted years ago (my words) consider that a lot of chemical holding tanks are coated on the interior with epoxies.   -Joe Person - show quoted text - Mark as complete
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  2. marksires added a post in a topic kitfox 4 with 582 flying   

    The artificial horizon is a Garmin G-5
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  3. marksires added a post in a topic TD main gears needed   

    I have a stock setup on my Avid now.  When I rebuild it, I'm either going with wider gear or convert it to a nose dragger, so I'd be happy to trade with you.  Shipping may be the biggest issue though - I'm in North Florida (although you may want to visit at this time of year :-) )
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  4. marksires added a post in a topic Friendly thrust competition   

    I'm old school NASCAR - "if you ain't cheatin, you ain't tryin" 
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  5. marksires added a topic in Jokes   

    Forced Landings

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  6. marksires added a post in a topic Fiberglass strut fairing POC   

    I believe it was Spruce.  I just bought a truckload (literally) of Spruce when Wicks had an inventory clearance auction last month.  I need to remake the fairings, since I found some rust under mine, and there is no way to get them off without damaging them.  I had priced the spruce several times, but never bought it because it pissed me off that shipping was almost twice as much as the spruce I needed (long length, UPS no likee).  I thought I was getting a small cartload from the picture on the internet, but it was a BIG cartload - filled the 8' bed of my pickup to the top.  I was afraid I'd have to take the cover off!  Admittedly, a lot of it was oddly cut, but I still ended up with enough good stuff to make a lot of parts from.
    The trip to get it cost about the same as shipping the pieces I really needed, but I got a lot more (plus a few other things - you know, auction!), and the spruce was really cheap.
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  7. marksires added a post in a topic Fiberglass strut fairing POC   

    No probably about it, at least for Avids.  Dean addressed that in one of the newsletters or a service bulletin.

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  8. marksires added a post in a topic home brewed nav lights   

    As I indicated, there are other experimental categories that can be used. However, if your 'guy' is flying his experimental 150 around as freely as an AB experimental, he is almost certainly violating his operating limitations.  The testing category is very restrictive - limited range, no passengers, etc.  The exhibition category is also restrictive - to and from events, and exhibition only at the event.  Unless otherwise indicated in the operating limits, no passengers.  Folks like EAA with Aluminum Overcast (B17), Collins foundation with their fleet of warbirds, and others have to jump through a bunch of paperwork hoops to get the privilege of flying passengers on those exhibition experimental aircraft.
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  9. marksires added a post in a topic home brewed nav lights   

    Breezy is not a certified airplane.  And you can't take a Cessna wing and put it on a Bonanza and call it an experimental.  Breezy works because using an existing wing still fit it within the 51% rule.
    This standard hasn't changed much, which is a good thing.
    If you've never dealt with the paperwork side, then you don't have any idea what it requires.  My work requires me to deal regularly with the FDA and other agencies as we do work for pharmaceutical companies.  The cost of the paperwork far exceeds the cost of producing the product/service.  I will say that compared to most agencies, the FAA has minimal paperwork, and a much more cooperative attitude - think that over for a minute!
    For an aircraft to be certified as an amateur built experimental, the build has to have performed 51% of the work.  On the Piper forum I hang out on, there is at least 2 or 3 inquiries a year on how to make their Piper experimental so they can get the advantages.  The answer is you can't.  There are other experimental categories you can get it recertified in, but they are so restrictive no one in their right mind would use them.
    If you've never had to work/fly in the certified world, you have no idea how wonderful the amateur built experimental world is.  A simple gas strut to open/hold open the door to my Cherokee?  $250 + $85 labor to install.  Form 337 filled out and filed, STC and instructions for continued airworthiness (5 pages) added to the aircrafts pilot operating handbook.
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  10. marksires added a post in a topic home brewed nav lights   

    I would agree the T Craft lights would be ok - if nothing else they 'look like' approved lights, so the chances of anyone ever questioning them is barely above zero.  Things that are obviously something else would worry me though.  And there is nothing wrong with having unapproved lights on the airplane to improve your visibility during the day - I'd light mine up like a Christmas tree if I had enough amps to!
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  11. marksires added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    I have a book from the early 1900's on spinning metal.  I really want to try it some day, it looks like a lot of fun.  When I got a lathe and a mill, I was looking for books to learn how to use them properly.  All the ones I could find were from the early 1900's, and man are they disorganized and hard to read.  Technical training books have come a long way since then!  Most of the ones I found were free on Google books.  I wonder if that Google project has died or is still working?
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  12. marksires added a post in a topic home brewed nav lights   

    Just because a part is on an approved aircraft doesn't mean it is approved for your airplane.  Standards change over time, and your aircraft must meet the standards in effect at the time it was issued its airworthiness certificate, and in the certified world, the part must be approved for your aircraft.  Otherwise you could take a Cessna wing and legally put it on a Bonanza...
    The standard for position lights is AC 20-74 ( )
    An approved position light will have paperwork indicating the standards it meets, usually TSO C30c for currently approved lights.  The manufacturer must also have a PMA (Parts Manufacturing Approval) to actually manufacture them AFTER they get them approved to the current standard.  Isn't dealing with the government wonderful?  Certified 'stuff' is expensive not because it is better, it is because of all the paperwork that it carries along with it.
    We are very lucky that the 'amateur built experimental' category exists!
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  13. marksires added a post in a topic home brewed nav lights   

    Here is the operating limitations wording from the latest FAA Order (8132.2H), Appendix C, Item 41.  Your aircraft may have slightly different wording depending on when it received its airworthiness certificate:
    Day VFR flight operations are authorized. Night flight operations are authorized if the instruments specified in § 91.205(c) are installed, operational, and maintained in accordance with the applicable requirements of part 91. (41)
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  14. marksires added a post in a topic home brewed nav lights   

    But if you check your operating limits issued with the air worthiness certificate, you will find a limitation to day VFR unless equipped as required in 91.205.  
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  15. marksires added a post in a topic home brewed nav lights   

    If you look at your operating limits issued with the airworthiness, they usually have blurb about 'day VFR only unless equipped as required in FAR 91.205(c)' or some such phrase.  That is why it applies to experimental even thought 91.205 indicates only standard airworthiness certificates are required to have them.
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