The main difference in weight in the different topcoats is how much you
wind up putting on. The pigments used in white house paint, Stits,
Randolph, Airtech etc are all the same and weigh the same. The difference
in weight of the base resins is negligible, the real difference in weight
of the dry, cured film is in how much you apply. There is probably more
pigment in latex house paint, as the manufacturer is trying for one coat
coverage, than in a typical aircraft coating. However, if you use house
paint you should be able to get by with less application thickness.
One word of caution, if you go the non-certified route and use latex house
paint or auto paint, you are serving as your own test lab. Unfortunately
with most of us this testing will occur on the plane as the final product.
Even if you make up some test frames and stick them outside for a few years
of exposure, its not real world. For example, make a test frame using
Duponts 2 part Urethane Imron for the fabric topcoat, it will appear to
weather just fine. However, put this same coating on a fabric covered
aircraft wing and it will crack and ringworm in a couple of years time.
Some will claim they have used auto enamels with success, but how thick did
they apply it and how many flight hours on the cover job? Latex house paint
may work fine for some, but if you follow someone elses lead you can't be
sure of the same results unless you follow the exact same procedure.
Rick Schreiber
> [Original Message]
> From: Oscar Zuniga <taildrags@hotmail.com>
> To: Pietenpol List <pietenpol-list@matronics.com>
> Date: 11/25/2008 8:08:26 AM
> Subject: latex house paint
>
>
>
> It sounds to me like it might be time for a scientific test. Lay up two
wooden test frames of a statistically-significant size (say maybe 2 ft.
square apiece), cover both using the same fabric, and then finish one with
the Poly-Fiber process and the other with the Fisher latex house paint
method (as detailed in Stevee's notes on Westcoastpiet).
>
> When completely cured, cut both test sections out of their frames and put
them on a digital scale and compare the weight. Multiply the difference by
the approximate number of yards of fabric used in a Piet project, and we
will then know how much difference there is in weight.
>
> I was quite surprised to see that John Dilatush's (now Greg Bacon's)
"Mountain Piet" also wears latex house paint. It's a beauty.
>
> I do value Ernie Moreno's input. He is a Tech Counselor and has quite a
number of fine projects under his belt, is extremely generous with his time
and talent, and lives at the Independence, Oregon airpark that spawned the
"Noon Patrol"... the squadron of 13 Nieuport replicas that flew into the
history books a few years ago as a remarkable group project. Pictures and
story at http://eaa292.org/noonpatrol_hi-res.html
>
> Oscar Zuniga
> Air Camper NX41CC
> San Antonio, TX
> mailto: taildrags@hotmail.com
> website at http://www.flysquirrel.net
>
>
