REFLECTOR: Jeffco Problem...worst day as a builder

[jewen at comporium.net]

Hi Chris,

Very sorry to hear about your problems.  The most obvious thing I noticed from pics 1 and 4 was the coloring of the flaked chips.  Most of the chips I could see have a tan color on one side.  This would lead me to believe that failure probably occurred in the material the Jeffco was applied to rather than the jeffco.  At one point I used a material called featherfill, I had some spots that failed to bond to the underlying area.  In this case the material that chipped off was purely the color of the featherfill since the featherfill failed to bond to the underlying material.  In your pics, it looks like the Jeffco was bonded and the failure might have occurred in the material under the Jeffco.  Not enough pics or data to come to a firm conclusion, but at this point I did not see any flaking on your baffles/bulkheads, only on the factory supplied strake parts.  Is it possible the strakes that were produced at the factory with a bad batch of epoxy or a batch that may have not hav!
!
e been mixed properly/ratio.

Not sure how much this helps resolve the problem, but it may make you feel better that it may not have been caused by your building technique.

Joe 


Not sure what your solution might be

---- Original message ----
>Date: Mon, 11 Aug 2008 21:28:40 -0500
>From: "Christopher Barber" <CBarber at texasattorney.net>  
>Subject: REFLECTOR: Jeffco Problem...worst day as a builder  
>To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>, "FlyRotary aircraft" <flyrotary at lancaironline.net>, <canard-aviators at yahoogroups.com>
>
>   Well, this was the worst builder day I have had.
>   That includes the day I realized I had to build a
>   new rotary engine, which, btw, was running better
>   each day before this fuel issue developed.
>
>   As the collective from the various list I am on may
>   recall, I have had persistent fuel leak issues. A
>   few weeks ago I had a visit from the fine men of the
>   Ellington/JSC/NASA fire department when I leaked a
>   few gallons on to the hangar floor while I was at
>   home sleeping late. Also, I thought my original
>   clear factory tubes failed due to ethanol. They had
>   turned color and became brittle (turns out they had
>   not YET leaked.
>
>   I tried sucking new Jeffco into where I thought the
>   leak was (very hard to reach area behind the spar. I
>   found a loose hard point and since I was having some
>   fuel seep through the floor of my cabin I thought
>   maybe the fuel was seeping in behind the hard point
>   into the foam to the cabin floor. Since the two hard
>   points from the strake fuel line were both put in
>   per plans years ago (before my choice to use a
>   rotary, thus auto fuel) they were installed with
>   EZ-84/flox. Since the flox around the loose hard
>   point seemed a bit "off" I decided to redo both of
>   them with Jeffco. At the same time I also took out
>   the factory fuel elbow fittings as mentioned above
>   and installed Vance Atkinson's gages. I did this
>   over the last few days.
>
>   I thought all was well, but when I added fuel to the
>   right strake only, I still had fuel seeping through
>   the cabin floor. So, I am having fuel leak though
>   the inner foam. I spoke with Velocity, Inc who
>   stated I could either go into the inner skin around
>   the stake storage area or cut a hole in the top of
>   the strake to find the leak. I chose to go into the
>   top of the strake as I thought it would be better to
>   not try to patch a leak from the outside. So, I cut
>   a hole in the strake to apply Jeffco to try to
>   find/cure the leak.
>
>   EEEEEEAAAAAKKKKK. I opened up the top right strake
>   and the Jeffco on the top of the strake was sitting
>   in the bottom of the tank. OMG!!!!. Almost all the
>   Jeffco from the top of the strake had fallen off. It
>   was all flaky and not adhering. Also, a number of
>   places from the sides and bottom had also fallen
>   off.
>
>   I called Velocity, Inc and they said they had never
>   had this issue before. They suggested I look in the
>   other stake to see if the problem was there too. We
>   discussed when I applied it and how. Now guys and
>   gals, I am not a complete incompetent. I know I
>   sanded stakes before I applied the Jeffco, I mixed
>   it well and per instructions. Also, the top strake
>   Jeffco was applied at a different time/batch from
>   the sides/bottom. The Velocity top strake is a
>   pre-built piece and is laid on the strake
>   sides/bottom in a separate step and the Jeffco is
>   applied to the top before you seal it, then you seal
>   it with more Jeffco.
>
>   I have never had more than about 20 gallons of fuel
>   in the system (about 60 total capacity). I have had
>   the fuel sit in the strakes for a long while though.
>   I used the Jeffco since it is supposed to be more
>   resistant to fuels like diesel and auto, even with
>   ethanol...at least that was my understanding. Some
>   ares of the strakes seem pretty good (but I don't
>   trust any of it now). I did get TWO, one gallon kits
>   of Jeffco back when I did this part of the build. My
>   first thought is that perhaps one of the buckets was
>   a bad batch. Donno.
>
>   I did cut into the pilot strake too. It was not as
>   bad. The top of the strake looks good, but I do have
>   some flaking on the sides. There are four
>   compartments in each strake. I cut into one on the
>   co-pilot side, and three on the pilot side so far.
>   One on the pilot side seems perfect (so far). The
>   inconsistency has me confused currently. But to be
>   honest, after dealing with this for a while and
>   trying to be philosophical about it...such as I
>   would much rather find it now, I walked away and
>   worked on re-attaching my ailerons after balancing
>   them.
>    
>   So, it seems many of those other fuel issue may have
>   not been the problem I thought they were....this
>   does seem to be the cause for when the fire
>   department came out as that leak just seem to
>   happen.  When I pressure tested this system a few
>   years back, all seemed fine.
>
>   I am posting the pix on the Canardzone but I am
>   posting this message on a few sites like FlyRotary
>   and the Velocity Builders site. The factory asked me
>   to post too so they could have a look and determine
>   if this may be a isolated incident (such as me
>   missing something big) OR if it could be a bigger
>   problem. Well, here are some of the pix I took....if
>   they are blurry, don't worry, it is only my
>   tears......
>    
>   The link to pictures is
>   http://www.canardzone.com/forum/showthread.php?p=25569&posted=1#post25569
>
>   All the best,
>
>   Chris
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