How to Mix Paint for a Spray Gun

I’m Scott. I design build and repair
woodworking pieces I’m opening up the doors to my shop to help you become a better woodworker Since publishing the video on how to spray-paint the staircase and wainscoting we’ve had a number of questions about how to spray paint This is the first video in a series we’re going to use to answer those questions We’ll answer questions about how to use a spray booth in a small shop, how to make sure you’ve got the right air cap set or nozzle on your sprayer, the difference between airless spray and HVLP spraying, and some clear finishes This video is going to cover off a question we had from our viewer that asked how to dilute paint for a paint sprayer Thanks for asking the
question Ben. Here’s your answer To measure the thickness of a finish
you need to viscosity cup What I do is I put the finish in my container here and I’ve put the cup inside until the fluid is overtop of it and then I start timing as soon as that that breaks the surface of the fluid I time how long it takes for this fluid to start to turn to a drip I’ve got a clock here I use that reference That tells me how many seconds I’ve got to get through that cup and I use that with my reference guide to figure out the right viscosity of the paint or the finish I’m working on Inside my spray manual there’s a section here that’s called the viscosity guide Here you use a viscosity cup to measure how long the fluid takes to get through the cup There are a number of different measurements here For latex paint it should take 20 to 30 seconds For primers it’s 30 to 40 For stains they go on undiluted And polyurethane should take 20 to 25 seconds to go through the cup I’m mixing up some primer for the paint sprayer so I can get some boards ready for a paint test but this primer you can see is really thick right out of the can You can see how it sits on top of the paint and slowly merges in I’ll show you with the viscosity cup how that’s far too thick I sped up this video and you can watch the second hand on the left-hand side here As the time goes by, I’m looking for a viscosity of 30 to 40 seconds for this primer but as I finish this at 40 seconds you can see there’s far too much paint in the cup I only paint with water-based finishes so I keep a clean container of water in my shop It’s a matter of experience that teaches you how much water to put in The first time I ever did this it took me about 45 minutes just because I was adding a little bit of water at a time and I didn’t want to overdo it What you need to do is really mix it up well and then you can test it out with a
viscosity cup I sped this up because there’s nothing worse than watching paint move but I’m going to slow it down right near the end so you can see what it looks like when it transitions to a drip This is normal speed here and
there you’ve got the drip I’ve got a 35 second viscosity here which is perfect for what I’m looking for, between 30 and 40 seconds A paint sprayer can work so fast and gives you the quality you just can’t duplicate with any other method this is something I’ll teach you more about in upcoming videos If you like this video please give it a thumbs up so others can find it and don’t forget if you subscribe down at the bottom here You’ll get notified when our next video
comes out the next one we’ve got scheduled for is this knock down booth that I use in my small workshop I’ll show you the ins and outs of how it works and how you can build one as well Until next time, enjoy your time in the