Re: [MV] CARC vs Imron

From: Cougarjack@aol.com
Date: Tue Feb 29 2000 - 09:35:22 PST


*This message was transferred with a trial version of CommuniGate(tm) Pro*
list,

I'm sure there are formulation differences, but yes, CARC and Imron are
similar concoctions. Each is a two part urethane paint, which, when mixed,
has a limited pot life. Each polymerizes to an inert hard plastic finish,
which is somewhat brittle on large panels. Imron is common on firetrucks,
emergency vehicles, and professional race cars. It has not caught on big
with the auto painting industry because of the special equipment needed to
spray it safely, and also because of cost. Auto body places are not the most
desireable neighbors these days, especially if they periodically emit clouds
of toxic green and yellow gas into the neighborhood.

A note on use is that it is NOT the best type of paint to use on large flat
panels, like slab sided truck doors and hoods. It tends to craze badly over
time if flexed. It gets big spider-web patterns of cracks all the way
through to the base metal. I have observed this on many Mil-vehs and a lot of
fire equipment. I have an M37 now that was painted with Imron in some past
adventure, and it will require a full stripping to remove the crazed and
damaged paint.

Imron and CARC alike, the danger is not with the finished product in place on
the vehicle. In this state it is harmless plastic, no more dangerous than
your screwdriver handle. During mixing and spraying, the robust chemical
reaction emits heat and toxic gasses, much like other urethane products.
(remember the home insulation scare years ago?)
When either finish is removed, then mechanical action of sanding or blasting
liberates quantities of dust, which if inhaled, remain in the lungs
permanently.
The point of using CARC on a truck is to prevent the absorption of nerve and
biological agents by the paint finish. Inert paint allows the truck to be
decontaminated by washing and neutralization. Urethane paint is practically
solvent proof, and few chemicals will affect it once cured. The former alkyd
based enamels were too permeable to be decontaminated well.
We all use finishes in our homes and shops which are similar to these two,
and which are certainly as hazardous. Oil based two part floor epoxies are at
the top of the hazard list, and those bathtub & tile refinishing plastics
are right in line behind them. If you allow someone to come into your home
and refinish your tub, you're using a CARC-like product, INDOORS!
CARC is not a special case, it's just that the connection with chemical
warfare agents has caused a lot of confusion and ungrounded fears. If your
cured finish is in good condition, and you are sure it's carc, leave it be,
and it will last forever. If you must refinish, let a professional do the
stripping and priming, and avoid exposure to the dust. BTW, it is only
necessary to rough the finish in ppreparation for the new paint..it need not
be taken to bare metal. CARC adheres like glue to steel, and makes a decent
base coat.
The exception to this would be a truck that was poorly prepared before the
carc was applied. (No, not the military...they would never do such a thing,
right? Right?.....)
If it covers a lot of rust bloom on the steel underneath the finish, even
CARC will not bar further rusting....it will just mask it from sight better.
Given enough time, all you'll have left is a CARC shell that LOOKS like a
truck. LOL! Tough stuff this CARC!

Remember that the Military looks at painting in a different light than we
do. To them, paint is a protective coating, like stucco on a concrete curb,
or the slime on a fish.
ROFL! They do not care if it makes the truck "look authentic" or if the
finish is exactly the right color. The coating must perform as per the
contract specs, and they don't feel obligated to explain their reasons to
civilians or the public at large. hence the confusion about CARC.

Comments folks?

In a message dated 2/29/00 10:41:20 AM Eastern Standard Time,
byrdhouse@netease.net writes:
....snippage here.....
<< I was told once that CARC is the same as Imron, but with grit added.
Anything to this? Imron is a paint that you need to be carful with, I guess
you do with any paint. Imron is very hard and durable when dry, and appears
much like CARC. >>



This archive was generated by hypermail 2b29 : Thu Mar 02 2000 - 22:30:41 PST