[VAC] Re: white top

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

R-19 in 4 mils and standing missile reentry sounds to me as more
fantastic than Jim Ross Lightfoot being elected governor of Iowa. Its
far more fantastic than the claims of Icynene that say R value isn't
important because the foamed in place product seals better. I fear that
won't fly when the regulators require a certain R value to meet building
codes. Worse, the Icynene product inhibits drying of wooden parts of the
structures which I believe will lead to structural failure from wood rot
in a decade or so. But I digress.

I'd tend to expect that R-19 was transitory, good for a few seconds of
reentry as the insulation ablated. A sample of aluminum coated with the
material should feel hot in the hands like good foam insulation if it
works.

Sometime about 25 years ago (instead of going to the Iowa state
Republican Convention as a delegate) I built an active solar collector.
I bought a can of paint supposed to make a super heat absorbing surface
for about $12 a spray can, but experiment with sheets of aluminum in the
sun with thermometers showed Krylon Ultra Flat Black accumulated
significantly more heat for $3.50 a can.

I don't know the NASA derived product. There should be something on some
NASA pages about it. NASA works at transferring technology to the public
on their web pages.

Since insulation R values are not trivial to measure, there are many
claims that are difficult to confirm. More often than not, when an
independent test doesn't confirm the maker claims the test is not
representative or applicable to the product. For example, a maker of
foam acoustical absorbers claimed the standard procedure for flame
spread was faulty, which I read to mean their product burns furiously
when ignited. They have since come up with a fire retardant treated
product.

Skeptical? YES VERY! Sounds too good to be true, and nearly everything
that sounds too good to be true, proves to be a lie. It would take
readily reproduced test results to convince me its true in test
apparatus that gave industry accepted values for other insulating
materials like foam and fiberglass bats.

Gerald J.