Using a Paint Viscosity Cup to Help You Achieve Better Paint Finishes


– All right, today we’re gonna
cover paint viscosity cups. We’re gonna cover how to choose one that’ll work well for
your particular paint, how to use different
cups to get a measurement on any paint that you may need, cross-reference charts
to determine viscosity. If you have a certain cup and another cup is what’s mentioned, as a timing and how to use the cup to determine how thick a paint is. We’ll also show you why
the paint viscosity cup is so helpful in achieving a good finish so you can know how to use it as a tool in your painting arsenal. So how to use, when we
use a paint viscosity cup, for example this is a Zahn cup, you fill the cup to the top with paint and then you begin to pull it out of your bucket or container of paint and what we’re gonna start doing, the moment that the stream comes flowing out of the bottom of the cup, we’ll start timing to
see how long it takes before there’s a break in the stream. One of the most useful
references with viscosities in general if a material flows at 20 to 30 seconds in a Zahn tube cup, it’ll spray easily with an HVLP spray gun. So you can use that as a
baseline reference point if you’re using an HVLP gun, if it’s much higher or lower than that, if it’s much higher you’ll
potentially need to thin it, if it’s lower you just
will have a very easy time spraying it, but want to
control volume of material. So here we go, out of
the material it comes and then as you can see,
I have a stream flowing. You can see in the top of the
cup the material will drain. I’m also timing this on my phone to determine how long it’s been ’til we start seeing the material stop flowing out of the cup. This is a very thick material, as you notice, it’s not flowing very well. It would depend how I
would want to spray this, if I’m using an airless, this
will probably work fine as is but if I’m using a spray
gun, whether it’s HVLP even conventional, I might need to thin it based on how thick it’s showing me here. All right, so we notice it’s too thick and actually in this case, a Zahn cup wouldn’t be well suited to measure this. As you can tell, the
stream isn’t consistent. To really use a viscosity cup, you need consistent flow of the stream and what we’re looking for is
a break in the stream’s flow. So we’ll thin this and we’ll review to show what it will look like. We’re also going to show a brief second of what this looks like sprayed out so you can see how much viscosity plays in to how a material sprays. All right, so that material
we just tested in the Zahn is running over 45, 55
seconds in a Zahn tube. And like we mentioned,
that’s usually beyond what can usually spray well with HVLP. For conventional as well if you’re looking for a fine finish. We’ll show you here, we have about 12 pounds of fluid
pressure on the pot, which is pretty limited and
not giving me excessive paint. I have a one four tip on the gun and then I’m using about 35 pounds of air when it gets to the gun it’s around 30. So we’re right about where
this HVLP gun is meant to run. What you’ll see with our
viscosity being as thick as it is (spraying sound) is I get a lot of splatter
and pretty poor results. Like I mentioned, when paint’s too thick, with an air spray gun especially, you won’t get good
atomization or break up. Now you may be able to spray it with an airless with a
little better results but that’s why a viscosity
cup can help you. It can help you prepare, to
choose the right equipment. It can verify that your paint
has been mixed correctly. We’re going to show you that now. We’ll add some thinner to
this material to get it closer to where it would be to
spray well with this gun. We’re also gonna show
you a conventional gun with the same material, just to show you the little bit better
breakup we might achieve. This is the same paint, same viscosity, nothing thinned conventional cast. Again, we can see it’s
very thick and orange-peely we’re not getting a good finish. So we’ll go ahead and thin this down and show you what the results are, we’re gonna be using water,
as a water based product. And we’ll be aiming for 30 to 40 seconds in our Zahn tube, and
show you the results. All right so we tried it un-thinned and we noticed the material
wasn’t giving us breakup and it didn’t look good at all. We went ahead and put in
10 to 15 percent of thinner into this solution and we’ll
go ahead and start the cup. Again, we start the cup
full and we pull it out. Once it’s out, we start a
timer, as you can see here. What we’re gonna wait for is both the cup to get relatively near the end, to empty out most of the
way to the very bottom where we’ll start noticing
a change in the stream. As you can see this
stream’s very consistent and even right now. Eventually, we’ll see what
we call a break in the stream which is when we’ll stop our timing and that’ll be considered how long the material ran in the cup. We can then use a chart that’s available to determine what viscosity we’re at. As I mentioned, usually
in the 30 second range, 20 to 30 seconds is an
ideal volley of time for in a Zahn tube for HVLP spray. So when you notice the
pattern start to slow down, and there we got a break,
so right at that point, we’re about 40 seconds, 44 seconds. So what we’ll do now, is we’ll show you what this looks like sprayed out and from there we may
need to thin slightly more to give you a good finish but
you’ll know as we learn here. So as I mentioned, the
material at this point’s around 40 to 45 in a Zahn tube, still on the little heavy end in our world for spraying typically. But we want to show you that we’re getting a little closer to where we’d want to be. (spraying sounds) So by no means is that
going to be a car finish, you can see there’s
still some thick chunks, but compared to our
earlier spray over here, we’re getting a lot thinner. We’re also going to show you conventional so you can see that
difference that’ll make. (spraying noises) So if you’re not concerned
with a car finish, maybe a general industrial finish, 40 seconds is not horrendous looking. But we’ll thin it a little
more so you can see, kind of final level when we get down to that 20, 30 second mark, you should see the finish
is even more improved. (spraying noises) Go ahead. All right, at this point,
we’ve thinned this paint about 20 to 25 percent, before
you’d thin a paint this far, you want to reference
your tech sheet on a paint to make sure you’re not over-thinning it and compromising paint performance due to it being over-thinned. So we’ll go ahead and time
it, like we’ve done before. And now we start a timer. You can see a good, solid stream. Cup’s getting close to being
empty so I start watching for that break in my stream, right there. I’m at about 19 seconds,
that’s actually right where we’d want to be for HVLP,
we’ll see how it sprays out. All right, so we thinned the
material down quite a bit, 25% or so, we’re at about
20 seconds in the Zahn tube. This is about where an
HVLP gun sprays well. With this particular material,
it’s a little over-thinned we’re using it for demonstration,
but you’ll see we might have some issues with runs and
that’s kind of the downside. If we over-thin the material,
and we make it run too fast in a cup or just in general,
it’ll run as you apply it because it won’t stick
to the surface very well. So we’ll show you what it looks like, you should see it breaks
up a lot better compared to the other two times that we
did some time tests in the cup. (spraying noises) So you can see, compared
to our other sprays, even though it’s pretty
good, it breaks up better, we do have issues with runs because it is too thin at this point. But that’s why a viscosity
cup can help you, by making sure it’s about
right where it needs to be. Around 30 seconds, this
material probably wouldn’t run and we’d have the finish that we needed. (spraying sounds) So that’s how you use a Zahn cup or a viscosity measuring
cup and then we’ll go over some options of different
cups so you can choose one that would work well for you in a moment.