Waterborne Paint Drying Problems – Waterborne Paint Spraying Tips for PPG Envirobase Nexa Autocolor


Hey this is Donnie Smith and I’ve got a
tip for you about reducing waterborne paint. I recently went to this last week went to
a waterborne school for PPG Envirobase Autocolor waterborne paints and we’ve using waterborne
paints, but I did get some tips here and it helped fix some of the problems that I was
having and I thought these maybe the problems you would have too because if you look in
the P-pages the technical data sheets for the Envirobase it is a little bit misleading.
I guess sometimes what they are putting here it should work, but it doesn’t because what
is actually working out in the field it varies a little bit than it does in here. You’ve
got to remember though that when these are printed it is in controlled environment for
example 70 degrees the humidity is certain range and everything. I mean if it is colder
or hotter it is going vary a little bit. But, there is one thing that is quite a bit different
and causes a lot of problems we were having. Metallics no problems and usually the metallics
have more problems than solvents. The metallics lay down great has had no problems with that.
We had no problems with blending. That looks great. The color matching is absolutely terrific
with waterborne, much better than it was with solvents. But there is one thing that I was
having problems with. That is drying, particularly white. We sprayed some whites and the students and
I had more troubles with white than any other color and we couldn’t get it to dry good.
And you may think the less water the reducer that use this is not tap water by the way
that is a special water they have. But you would think the less water the better it would
dry. But in fact it is kind of opposite. If you put more water and it helps it lay down
it helps it dry better. So if you look in the P-pages that talks about reducing says
to add reducer anywhere from 10 to 30% and that is a little bit misleading because just
about nothing reduces to 10%. In fact it says for solid colors require reduction of 10%,
metallics require 20, mid coats 30, you can forget about all that. They said at least,
everything start at about 20% and then check the viscosity. Viscosity is you take a viscosity
cup and you test how long it takes, you got to time it. This is anywhere between 23 and
25 seconds that is where you want regardless of what you are spraying in waterborne. So
if you will do that. If you are having problems with your solid colors and think about reducing
them quite a bit more than it mentions in here. I think we started at 25% and then moved
up from that until we got that viscosity just right. Whenever I sprayed it like that it worked
fine. It went on better and we didn’t have drying problemes. In this case when you have
solids then add more water it dries better. So I kind of hate; it is kind hard to teach
like I use always recommend to the viewers, the DIY, and students to always follow these
P-pages, but sometimes there are things in that doesn’t work and that is one I am going
to point that out to you. Anyway I just thought that I’d share that with you. If you are
using waterborne be sure and play with that reducer a little bit. Worry about the viscosity
not the parts. Like with solvent, It is all about the parts you want exact. Well this
is not the case. I mean this to me if you remember the lacquer days it kind of reminds
me of that. What we would do with lacquer? We would reduce it until spray right. On a
colder day the lacquer is going to be thicker on a hot day was going to be thinner so this
kind of a same thing. It is not about parts it is about getting it at the right viscosity
before you spray. So don’t be afraid to mess around with the reducer a little bit
get it right and check it with the viscosity cup and that may fix a lot of problems you
are having too. Anyway that is it for this tip we will talk to you next time.