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

Tue Aug 12 15:19:38 CDT 2008

When chris and I first sealed the fuel system it held balloon pressure, 
so it led us to believe there were no leaks

Dave

bdtopp at comcast.net wrote:
> 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&posted=1#post25569
>     <http://www.canardzone.com/forum/showthread.php?p=25569&posted=1#post25569>
>
>     All the best,
>
>     Chris
>
>
> ------------------------------------------------------------------------
>
> Subject:
> REFLECTOR: Jeffco Problem...worst day as a builder
> From:
> "Christopher Barber" <CBarber at texasattorney.net>
> Date:
> Tue, 12 Aug 2008 02:33:46 +0000
> To:
> "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>, 
> "FlyRotary aircraft" <flyrotary at lancaironline.net>, 
> <canard-aviators at yahoogroups.com>
>
> To:
> "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>, 
> "FlyRotary aircraft" <flyrotary at lancaironline.net>, 
> <canard-aviators at yahoogroups.com>
>
>
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