marksires

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Posts posted by marksires


  1. One of the reasons we shut down airplanes with fuel starvation rather than ignition is to make sure there isn't a fuel/air charge sitting in a cylinder ready to 'go' if someone moves the prop and the mag P-Lead is busted, or a nice hot lead ball isn't still there to give them a really bad day.  Even after cool down, the lack of fuel in the float bowl/fuel lines reduces the chance of an inadvertent start on prop movement.

    In our 2 stroke, gear reduction engines, I'm not sure if that is a big concern or not.

    Mark

     


  2. 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
    1 person likes this

  3. Thanks for posting the video Mark.  Who makes the instrument in the center of your panel with the artificial horizon on it?  What can you tell me about it.  Also curious about the reserve lift indicator.  What are your thoughts on it?  JImChuk

    The artificial horizon is a Garmin G-5

    1 person likes this

  4. 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 :-) )

     

    Mark


  5. 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.

    Mark

     

    2 people like this

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

    While ya'll are monkeying around with the fairings please remember that they are indeed structural.  Unless you address the structural issues (I made mine out of 1" X .058" tubing) then you need the wood fairings installed, or something that will give you the rigidity of the wood fairings.

    :BC:

     

    You're probably right Leni,  my Kitfox 4 project flew for about 640 hrs with no fairings, but it does have the 1" lift struts.  JImChuk

    1 person likes this

  7. 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.

    Mark

     

    I used to fly with a guy that had his Cessna 150 registered as an experimental so your wrong about not being able to move from certified to experimental. A more recent example would be Draco.

    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.

    Mark


  8. 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.

    Mark

     


  9. 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!

    Mark

     


  10. Here's a interesting link for those thinking about spinning a spinner out of metal.  https://www.youtube.com/watch?v=JgRLWAPgD7s

    I mentioned people buy wood lathes such as yours and add riser blocks under the head and tail stock to get the clearance needed for spinning. I've seen them take the wheels out of an old pair of roller blades and use them to make spinning tools. After watching the video it will be a little more clear how the roller blade wheels are used. You don't want 6061 as a material for spinning. There are other grades that work better for spinning.

    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?

    Mark

     


  11. 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 ( https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_20-74.pdf )

    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!

    Mark


  12. 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)

     

     


  13. 91.205(c) part 2 - Approved position lights

    Also part 3 - anticollision light must be approved (even in day VFR if aircraft is registered after March 11, 1996 )

    https://www.ecfr.gov/cgi-bin/text-idx?SID=6744ba5e6f946ba5d34803a569e01de5&mc=true&node=se14.2.91_1205&rgn=div8

    Unfortunately 'experimental' is not a get out of jail free for this one.

     

    Mark

     

     

    Paragraph (a) does say standard category airworthiness certificate

    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.  


  14. 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.


  15. Buckchop,

    The door is great, and with this kind, you wouldn't have to reengineer the building, since it doesn't put any load on it opening.  It is also very nice to not have any locks or latches to worry about.  The catches are at the bottom, and engage during that last 1 foot.  If anyone can lift the 4000lb door up to disengage them, they are welcome to anything in that hangar!  :lmao:

    1 person likes this

  16. Well I've been fighting with bad brakes on the Avid for a while, and thought I had fixed the problem with the new brake pedals.  They were super sensitive though, and it was hard to stay off the brakes.  Also, I thought the leverage could be better.  I bought a set of the shortest master cylinders Matco sells.  # MC4GH  www.matcomfg.com/catalog.html?Tp=6&adv_search%5B1%5D%5B37%5D=0&adv_search%5B4%5D=5&adv_search%5B1%5D%5B56%5D=0&adv_search%5B1%5D%5B38%5D=0&adv_search%5B1%5D%5B39%5D=114&adv_search%5B1%5D%5B41%5D=0&adv_search%5B1%5D%5B42%5D=346&adv_search%5B1%5D%5B43%5D=0&adv_search%5Bkeywords%5D=&sbT=Go   They are only 5" long, the next length Matco sells is 6 1/2" long.  If there was a 5 3/4" length, it would be just right.  I was going to use some brake pedals from a Kitfox 1, cause they have way better leverage then the Avid brake pedals.  I did end up using them and it seems like they will work fine.  Couldn't really test out the brakes, cause I have snow on my runway, but I think they will work out.  I'm not riding the brakes, and it doesn't take much push to lock the wheels.  Course it's in snow, but still I feel it's going to work out.  If I remember right, with the Avid brakes, the master cylinder hooked on about 2 1/4" from the pivot, on the Kitfox pedal, it's about 1 1/4" to the pivot.  The new cylinders are 5/8" bore, the old ones were 1/2" bore.  All in all, an improvement in pressure I believe.   I had to make up a bracket on the one side to mount the cylinder in the right place, what I did would not involve pulling the rudder pedals out and welding tabs on them, although, that may be a better way to do it.  I think the nice thing about this is you could use your existing Avid pedals, if you weld new arms on them to mount the master cylinder to.  The left pedal would get turned around 180 degrees and the existing arm would be cut off.  I did make some extensions for the bottoms of the cylinders to make them longer, but you could also weld the new arms lower to make up the difference, and that would probably give you even better leverage.  Well I'll quit typing, and try to find the pictures now.  Don't laugh at the crappy welding.  It should hold.  JImChuk

     

    I used the same brake cylinders, and although I total redid my pedals, the basic end result is the same.  Much better braking.  With the old stock setup, I couldn't hold 3,000 rpm, now I can hold to about 5,500 rpm.

    Mark

     


  17. Do you plan on painting it? My plan was to polish then epoxy paint. The FBO I use to work for was painted. You spill some oil and you mop it up. It sure was easy to clean!

    Why termite protection? The structure is all steel, right?

    I also found out that termite treatment is required in Florida for all structures, regardless of construction type.  We have nasty termites here, and they will find any cellulose in a building,whether structure or just a cardboard box on the floor.

    Mark

     

    1 person likes this

  18. Final inspection today - Passed!!!  I have my Certificate of Completion printed, so I can hang it on the wall!

    Hooray - 1.5 years in the making, but since I worked only weekends, and we've had record rainfall in Florida since I started this project (this month we normally have 3", we've had 9" so far) so I missed a lot of weekends before the roof was on, I don't think that is too bad.  Did it all (my son and one other person helped) except the concrete and the drywall.

    Place is a mess at the moment, now that is done I can concentrate on cleaning it up and organizing.....  I'll take pictures when it is presentable.

    Mark

     

    1 person likes this

  19. Jenki, not the same as split lock or spring.  both of those are to keep the fastener from becoming loose.  Belleville washers are to keep the connection from coming loose, or to keep constant, predictable pressure on a connection.  One use of them is when fastening a wooden propeller, so as the wood expands and contracts with humidity the connection to the hub stays tight.

    Mark

     


  20. Jenki,

    Belleville washers are washers that are not flat, they are cupped, and if not made of spring steel, have some spring to them so they keep pressure on the bolt/nut when they are torqued down correctly.  The amount of pressure can be varied by changing how much torque is applied to the bolt.

    Mark

     

    1 person likes this

  21. Aeropoxy seems to be the best epoxy for fuel tanks.  I have Cozy plans, and hang out on the Cozy forum as well.  All reports of Aeropoxy used in the fuel tanks are positive.  On user did a coupon test with various epoxies.  Most worked fine, but Aeropoxy held up a year in a bottle of E-85.

    Mark