Painting Over Oil Base Question
crashboy
with an oil base paint. The house is ten years old. I would like to repaint
and change the trim color. I tried rubbing some toulene on the trim to see
if the paint would come of easily. I did not. I was told this was one way to
tell. I would really like to paint over it with Latex water base. Sherwin
Williams Classic 99 or Super Paint is my choice replacement but my wife is
convinced the latex will come of if the orginal was oil based. I have tried
a sample and that seems fine to me.
So my question will latex hold up if applied to trim over old oil base. I am
planning to use pure white, semi-gloss Superpaint ? Any help from the pros
out there would be greatly appreciated. Thanks in advance.
steve
quality paint system you get a much better results. The TSP will remove all of
the oils and etch the existing paint system. This will allow the latex to
stick.
Steve from NH
Paul Broussard
> (snip)
>
> So my question will latex hold up if applied to trim over old oil base. I am
> planning to use pure white, semi-gloss Superpaint ? Any help from the pros
> out there would be greatly appreciated. Thanks in advance.
Carl-
Let's get the nomenclature down first. Latex paint covers a wide swath, usually
just about any paint that is waterbased. Now, an acrylic latex is the latest
advancement in coatings, that really has come into it's own in the last 10-15
years. Most exterior paints nowadays are 100% acrylic or acrylic latex,
whichever the manufacturer names it. That said, we're talking about acrylic
paints, not latex paint. SuperPaint is an 100% acrylic.
We generally don't like to convert to a good acrylic paint without priming with
an acrylic primer first. However, many manufacturers claim their 100% acrylic
exterior paints will stick to oil based finishes. This may be somewhat true,
depends on the paint. I've found that it does well if the oil paint has faded,
most good acrylics will stick fairly well. The problem is the gloss level of the
oil paint. If it still has a gloss in the protected areas, you may have some
adhesion problems. Still, you should scuff sand the oil paint to get a good
mechanical bond.
It can be done, but for us to guarantee it, we'd insist on priming with an
acrylic primer. A good one sticks like glue. This doesn't present a major
problem, as we usually apply 2 coats on an exterior paint job.
Sherwin Williams also has a new coating guaranteed for life called Duration.
It's much thicker than regular acrylics, leaving a coating almost twice as thick
as normal paints. Guaranteed to stick to oil paints. It's expensive, and it's
marketed as a one coat system. You may want to check into that.
--
Broussard Paint Contractors, friend of Bill's
"careful, we might learn from this"- Calvin
family pics from Paul & Laurie-
http://members.home.net/pbroussard/index.html