[AT] Salting roads (was Re: Trans. fluid

[Mike Sloane]

The problem with "salt" (sodium chloride - NaCl) is that it doesn't work 
much below about 15°F (-9°C). But it turns out that our old friend 
calcium chloride (CaCl) is effective down to much lower temperatures 
than common salt. So if the road department sprays some liquid CaCl on 
the road *before* the precipitation, it will prevent the "black ice" and 
hard pack snow from forming. Another alternative is to spray the regular 
road salt with the CaCl right before spreading it, that will increase 
the effectiveness of the whole process.

Needles to say, if you see the trucks spraying liquid down before a 
storm, you DO NOT want to be following them with your vehicle. :-(

The only reason I know about this stuff is because I am part of my 
town's government and have responsibility for the DPW. We are 
investigating the various alternatives to just dumping large amounts of 
(increasingly expensive) salt on the town roads. I recently took a 
"field trip" to a nearby town to see how they were dealing with the 
issues <http://public.fotki.com/mikesloane/allamuchy-calcium-c/>. For a 
number of reasons, we will more likely be going with an arrangement to 
spray the regular salt with liquid CaCl as we load it onto the trucks.

If you think salt is bad for the underside of the vehicles, you should 
see what it does to the spreaders and truck bodies, even when we hot 
pressure wash them after applying the salt. (I suggested that they not 
bring the trucks inside the building after spreading, but that just 
creates a different set of problems.) The next truck we order will 
likely have an aluminum body.

Mike

charliehill wrote:
> Ralph that is kind of what I meant.  I figured you lived far enough out of 
> town and moved around little enough in the winter that you didn't get in a 
> lot of it.  I'm sure there is plenty of the main roads and in town up there. 
> It is used here when necessary but that's maybe 3 or 4 days a year and most 
> of what we get is a liquid compound sprayed on the roads the night before 
> they think there will be some snow or ice.
> 
> Charlie