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

Tue Aug 12 10:07:41 CDT 2008

Chris;

Boy, that definitely is a very bad day. But then history is history, and we
can only deal in the present.

I can't offer anything additional as cause, but I wouldn't put the blame on
the use of auto fuel.  There is no evidence that I am aware of that EZ poxy;
when properly mixed and cured, has any incompatibility with the fuel.  There
are EZ flyers that have used auto fuels for 15 years without problems.  

I've had auto fuel in my tanks for 6 years, and haven't noted any evidence
of damage to the epoxy.  I did have a few pin-hole leaks on the inner skins,
and then found that the fuel had wicked through the glass plys in the skins
that had not been completely wetted out at the factory. I attributed those
leaks to me not being thorough enough in coating the very porous skins on
the strakes as delivered. There is an EZ flyer in Oregon who has used fuel
with 10% ethanol for years without an issue.

The caveat, of course, is perhaps the issue that Joe raised about the proper
mixing of epoxy used.

Back when I was finishing my strakes - I guess about 9 years ago (yikes!) I
talked with the folks that made both EZ-poxy and Jeffco.  The issue of good
bonding of one to the other did come up, and the uncertainty of the coating
adherence was enough for me to decide against it.  That apparently changed
later.

Tenacity, tenacity - and all issues will be resolved.

The very best,

Al

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of bdtopp at comcast.net
Sent: Tuesday, August 12, 2008 5:10 AM
To: Velocity Aircraft Owners and Builders list; Velocity Aircraft Owners and
Builders list; FlyRotary aircraft; canard-aviators at yahoogroups.com
Cc: Christopher Barber
Subject: Re: REFLECTOR: Jeffco Problem...worst day as a builder

Chris,

   Sorry to hear about your problem.  It was mentioned earlier (forgot who
responded to your email) that maybe the material the Jeffco bonded to failed
instead of the Jeffco itself failing.  There is evidence of this by the
yellow discoloration on the Jeffco chips.  Here is a possible senerio to
think about when trying to figure this out.

   When you originally built the strakes and coated with Jeffco, there was a
small leak somewhere.  This allowed a very small amount of auto fuel to leak
into the foam.  The auto fuel started to slowly break down the EZ84
underneath the Jeffco.  This may of continued to leak which in turn caused
more leaks as the Jeffco broke down and chipped away.  In other words, it
deteriated over time getting worse and worse.

   Maybe it wasn't the Jeffco that originally failed?  Something to think
about anyways.  Good luck with your repair.  

Bruce Topp

-------------- Original message -------------- 
From: "Christopher Barber" <CBarber at texasattorney.net> 

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 bot! h put i n 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
<http://www.canardzone.com/forum/showthread.php?p=25569&posted=1#post25569>
&posted=1#post25569

All the best,

Chris

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