Cheers:
(probably few as I am slow), I have some stats gleaned from the log
which MAY prove of casual interest......
I have now spent 1158 hours building, and many more arranging,
preparing, staffing and sorting. To date I have built Vert. fin, rudder,
stabs and tabs and both wings (with the 1/2" bolts mod).
The weather finally broke this week with night temps of 14deg C and day
maximums of a dry 22 - 25deg C., perfect for filling wings, I thought.
This morning I spent three hours filling the stbd wing bottom surface.
This completes the set. This aft, I spent three hours sanding it all off
the port wing bottom. This last is not finished, but it's a promising
start.
My method has been to moisten the surfaces with MEK to repel oils and
sand the surfaces by hand (per the manual) to give initial teeth to the
filling. I have found that a VERY CURSORY layer of epoxy on the wing
afetrward, tends to thicken during the 45 minutes it takes me to mix all
that airy-fairy plastic Xpancel into the mix. This really makes the fill
stick when applied and as an adjunct, gives me a super view into the
structure, as it makes the surface transparent. Let me say that I used
only about 45 grams of epoxy per wing top/bottom, by cutting a Chinese
brush short to 3/4" and "stippling" the epoxy sparingly onto the surface
(took about 30 minutes to stipple and leaves a muted shine). The epoxy
is disarmingly liquid in that it imperceptibly wandered down into every
tiny pore. Having done the stabs and tabs, I had an inkling as to the
ratios of surface area to weight of fill. It turned out that mixing the
fill to bread dough consistancy took 45 minutes for a pot - and piles of
@#$%
& patience, as the airy-fairy tends to leap from the mix before you
can incorporate it. Nevertheless I found that for separate mixes, I
averaged 8.3% of the weight of mix was Xpancel, over a seven mix series.
I then used this to preweigh the #$%
& so as to have a chosen box of it
available as soon as the epoxy was finished on the mixer. This speeds
up the process
As for what I added to fill the wings, I kept a log of weights of
materials. I was afraid of wildly differing numbers when I began the
second wing, but ir all averaged out fairly consistently:
e=epoxy mix; x=#$%
xpancel; m=fill mix
TOP Starboard WING: 40e(stipple) + (575e + 93x) = 40e + 668m
BOTM " WING: 45e + (340e + 42x) = 45e + 382m
STARBOARD WING TOTAL: 85e + 1050g MIX
TOP Port WING : 45e + (394.4e + 44x)= 45e + 429m
BOTM " WING : 51e + (533e + 53x)= 51e + 586m
PORT WING TOTAL : 96e + 1015g MIX
So, what I have added to each wing is less than 100g epoxy to prepare
the surface, and about a kilo of #$%
& mix to fill. There are a number
of minor additions in the way of leading edge and installation jobs
which will add a minimal amount, but that'sd basically it. I have no
idea what will be sanded off, so don't know what the end result will be
as far as weight goes. Plus (actually MINUS) some weight will be
diffused gasses in future curing and baking.
STARBOARD bottom, 3.5 on the PORT bottom, and 3.0 on the STARBOARD top
in that order - so there is a learning curve! (plus my wife did some
stippling).
I don't know if this is any use to anyone, but perhaps it was worth
chronicling for comparison. XS wings are just a dream here.....
Happy Landings,
Ferg #A064 (319)
|