REFLECTOR: Jeffco Problem...worst day as a builder
Christopher Barber
CBarber at texasattorney.net
Wed Aug 13 14:02:45 CDT 2008
I agree. Don't know about complety rebuilding, but I too would have thought
the Jeffco should have acted like a bladder. I did not use wax coated cups,
but the premise is sound. I missed something, to my great chargrin now.
Mostly I hope to get to the root cause so I can move forward.
I am waiting to talk to Scott Swing again. He asked for me to post some
pictures and I gave him the link to Canardzone earlier today. I called a
few minutes ago but he is in a meeting. I am curious on their take. He
expressed legitimate concern especially since they too use Jeffco.
Hopefully the combined wisdom will help us get to the bottom of this. Even
if we determine "simple" builder error, at least it can add to the
collective wisdom.....one more way not to have a filiment for a light bulb,
so to speak.
I am currently consiering various options. I hope not to have to completly
redo the strakes. However, cutting out about everthing down to the lower
outer skin or foam is on the table. Sandblasing, sanding, new bulkheads,
laying glass over the bad Jeffco to form a hard bladder have all been
mentioned. I have noticed how no one has mentiond how fun building is
lately <g>.
Alex Balic stated he may be able to stop by on Friday. I look forward to an
informed observer taking a look. I appreciate his and others offers of
assistance.
I believe the larger concern, regardless of there being hundreds of flying
planes with EZ84, Jeffco etc out there is that in the recent past Ethanal
has been added to the equation. While it may do nothing to our epoxies, it
has had some serious issues with other substances in common use. I believe
rubber hoses is one such issue (older vehicles using biodiesel have this
problem...my '06 Jetta does not). Also, others have mentioned that gas
companies now dump all sorts of chemicals in fuel these days. I donno, but
I do know one of the great things about "standards" is there are so many of
'em <g>
All the best,
Chris
-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
Behalf Of Laurence Coen
Sent: Wednesday, August 13, 2008 9:53 AM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Jeffco Problem...worst day as a builder
Chris,
I think the first thing to look at to find the real problem is the fact
that there are hundreds of flying planes that have non leaking tanks with
internal coatings of EZ-84 or Jeffco exposed to both 100LL and auto fuel.
Even if the Jeffco didn't bond well to the EZ-84 it should still remain
intact and act like a bladder in an aluminum tank. The fact that it cracked
up and seemed to curl would make me think that the Jeffco was somehow
contaminated. It could be something as simple as a wax costing on the
container you mixed the Jeffco in or perhaps something used to clean the
strakes prior to the application. In any event I would take the suggestion
that you completely replace the strakes very seriously.
Larry Coen
N136LC
From: Christopher Barber
Sent: Monday, August 11, 2008 9:28 PM
To: Velocity Aircraft Owners and Builders list ; FlyRotary aircraft ;
canard-aviators at yahoogroups.com
Subject: REFLECTOR: Jeffco Problem...worst day as a builder
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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