Steve B wrote:
"dadiOH" wrote in message
...
Steve B wrote:

I was merely asking if the liquids in enamel would be bad for an
airless sprayer. I have since read up, and have changed to an
alkalyd paint, as it is gentler on the sprayer, and has a good
outdoor performance rating.

What liquids are there in "enamel" that there aren't in alkyd paint?
Actually, how does alkyd paint differ from "enamel"? AFAIK, enamel
(paint) is just glossy oil paint. Or maybe you mean a water born
alkyd? --

dadiOH

Herein lies my confusion.

I used to use enamel way back before California outlawed it, and then
the ornamental metal business had to readjust big time. At that
time, in the 80's, I used what was called "enamel". It used solvents
to clean up. It was an oil based paint, and water would not clean it
up very well from tools or sprayer.

I tend to think that what I am thinking about is VOCs. The stuff in
the paint that keeps it wet while contained, and help it dry when
exposed to air. And the VOCs (volatile organic compounds) would be
what eats on the soft plastic parts of the sprayer.

Enter: alkyd. Described as a synthetic oil vehicle that cleans up
with mineral spirits. Not sure what the VOCs, or comparable
component, does to plastic parts, but the fact that it would clean up
with common thinner makes me think the VOCs are not as strong or
corrosive as other solvents used to clean up paint.

I am asking what to use, as I obviously don't know. I am going to
paint the exterior of two ocean-going containers, along with some
corrugated metal I put on them. It is going to be exterior, exposed
to a harsh environment. I would like to go with something that it
doesn't take plastic eating components. I have used alkyd before,
and it performs to what I want. The clean up seemed easier than
"real" enamel.
So, I would appreciate any suggestions on what to use.

I would use a paint that is meant for that purpose. Most likely, an oil
paint, possibly poly (not likely to find that except at a marine store).
Read some at
http://www.rustoleum.com/CBGProductFinder.asp?pfm=BBS

Automotive paints should perform well too. I know nothing about them but
here, briefly, is what I know about paint in general, learned both
empirically and by reading...

Paint is a coating meant to protect and/or beautify a surface. All paints
consist of:
1. a material that will dry and/or cure to a film (a resin)
2. a liquid to keep #1 in suspension or dissolved until use (a vehicle)
3. something to make it opaque; used to be, it was usually white lead,
now, most is titanium oxide
4. color
5. possibly, other materials to modify properties of the above

Take away the last two and you have varnish. (Or lacquer. Or shellac.)

There are a whole bunch of different types of paints but for our purposes we
can divide them into two: oil base and water base.

Water base paints use acrylic, vinyl, PVA and others for the resin, water
for the vehicle. Their films are durable and elastic but not very hard.

Oil base paints use alkyd, polyurethane, phenolic and others for the resin;
the most common is alkyd. They use petroleum based products such as mineral
spirits for the vehicle (used to use turpentine). Their films are durable
and hard but not very elastic. Any of various oils are added to the mix to
increase elasticity but at the expense of hardness...more oil = more elastic
but less hard. Nothing in oil paint will hurt your sprayer.

When you were talking about "enamel" you were really talking about plain old
oil paint. AFAIK, it is always glossy unless something else is added to it
(by the manufacturer) to reduce the sheen. Used to be, you could go into
any decent paint store and buy some flatting powder (talc). Ask for that
now and all you would get are blank stares.

The manufacturers of water base paint call some of their product "enamel".
It isn't; it is neither hard nor as glossy. Moreover, it takes months to
cure...set something on a shelf six months after being painted with it and
it is very likely it will wind up stuck to the shelf. I think acrylic
paints are great for walls, wonderful for the exterior of a house but suck
for anything else.



--

dadiOH
____________________________

Winters getting colder? Tired of the rat race?
Taxes out of hand? Maybe just ready for a change?
Check it out... http://www.floridaloghouse.net