De-icing

Newps wrote:

Outdoor sprinklers are filled with air in the winter.

Not all, by any means. When I worked for Grinnel Fire Protection, we frequently
designed sprinkler systems which used anti-freeze. These were closed-head
systems. The water was shut off at the main valve and the system drained. There
was a filler port at the top of the system, and it was filled with anti-freeze.
Then the water was turned back on.

If a fire occurred, one or more heads would blow, the anti-freeze would drain
out the open heads, and water would follow from the mains. After the fire was
out, the system had to be drained before it froze.

This type of system was very popular as an outside branch of a larger inside
system; for example, a few heads providing protection for an outside truck
loading dock.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

City Dweller wrote:


How about applying a stream of hot air (a hair drier-type device)?


Last winter, after a nasty ice storm, we tried the hair dryer and it
was worthless. The wind just blew the tiny stream of hot air away. A
friend used a propane heater with a big heating duct and set up some
sort of a small hood to hold the hot air in, it worked for him.

Hai Longworth

The pink stuff could be ethylene or propylene glycol, but it still works in
combination with hot water and a garden sprayer for deicing purposes. And
no, I don't live down south, but actually reside in Wisconsin, where ice and
flying in ice are concerns from October through May.

I actually stopped using it, since I now collect the overflow from filling
my TKS and spray it on the plane. However, the pink stuff does work, and is
a lot cheaper than car antifreeze, and doesn't contain the rust retardant,
although I don't know whether it would be a problem or not.

Alchohol, hmm, I think ISOPROPYL alchohol (there are three kinds of
alchohol) works well. So does car windshield washer fluid.

Alchohol, hmm, I think ISOPROPYL alchohol (there are three kinds of
alchohol) works well. So does car windshield washer fluid.

There are many many many kinds of alcohol.

Doug wrote:
Alchohol, hmm, I think ISOPROPYL alchohol (there are three kinds of
alchohol) works well. So does car windshield washer fluid.

Doug,
We use isopropyl alcohol mixed for defrosting and for washing off
the slushes. By itself, it can not help to melt ice.

Hai Longworth

Kobra wrote:
: So how to you all de-ice your planes and are my mechanic's fear justified on
: the use of auto anti-freeze?

I have a set of wing & tail covers by Kennon. The ice & snow just peels off.
Don't put the covers on when the wings are wet, though, as the fabric gets
stuck to the wing. Get a set of dark colored covers and the solar heating
will help clear the ice off the covers in no time - mine are maroon.
--
Aaron C.

Well I have two solutions...no pun intended ;-)

1) Automobile windshield washer. Good to -25, cuts ice, and works. Best for
the light stuff. I like to heat it.

2) Isopropyl Alcohol, sprayed on to cut the ice then apply with a different
sprayer RV antifreeze bought at Home Depot. I hear one could mix these two
together 50/50 and get a pretty good third solution that cuts and prevents
refreeze in one application. I would heat this one carefully ;-)

3) Most importantly, be careful of refreeze. Hot water is not enough!!

Bill Snow, PE, CP, IA, ASEL

To clear up a few points.
Both Alcohol and antifreeze and deicing solutions ( as well as salt, and
almost any other substance that dissolves in water ) lower the freezing
point of water. So both alcohol and antifreeze both effectively melt the ice
by lowering the freezing point to below the current temperature. Since the
sprayed solution only contacts the top layer of the ice, it melts it away in
layers. The idea that one only melts and the other only prevents refreezing
is an OWT. Using a heated substance will melt it faster because you
simultaneously raise the temperature and lower the freezing point.

Some mentioned that spraying hot water only on the plane is prone to
refreezing in a dangerous way. Sage advice.

A correction: what I meant was that isopropyl alcohol by itself is
very ineffective against large amount, solid block of ice. It has
lower freezing point than water so it will dissolve the ice layer by
layer very slowly. To loosen up large block of ice, we use hot (not
super hot) water in a plastic bag as mentioned earlier.

Hai Longworth