Sprayer Not Atomizing Properly

[Ken Krawford]

I thinned it again today (didn't measure exact amount of added water) and measured 94 seconds in a Ford cup. The spatter was a bit less than yesterday but not much. When wet, it looked I'd just finished a class in "What orange peel looks like". Fortunately the paint leveled before drying and the results looked pretty good.
I'm painting this bench for my son and he just put down about $90 for a gallon of Duration so buying another product wasn't going to fly. What actually happens when a product is over thinned? Will it not last as long, fade or fail to adhere properly?
Also no mention was made of using a larger N/N set. Would just make the spatter problem worse without having any more air flow from the turbine to drive it?
Thanks again for all the comments.

[John TenEyck]

You didn't mention you had a larger N/N set. Yes, of course, the higher the viscosity the larger the N/N needed to be able to spray something uniformly (without spitting and sputtering).

John

[Jason Roehl]

I thinned it again today (didn't measure exact amount of added water) and measured 94 seconds in a Ford cup. The spatter was a bit less than yesterday but not much. When wet, it looked I'd just finished a class in "What orange peel looks like". Fortunately the paint leveled before drying and the results looked pretty good.
I'm painting this bench for my son and he just put down about $90 for a gallon of Duration so buying another product wasn't going to fly. What actually happens when a product is over thinned? Will it not last as long, fade or fail to adhere properly?
Also no mention was made of using a larger N/N set. Would just make the spatter problem worse without having any more air flow from the turbine to drive it?
Thanks again for all the comments.

Acrylic coatings have long polymers in them that are intended to tangle with each other when the carrier evaporates. Other liquid modifiers help keep the polymers from balling up on their own without intertwining while the carrier evaporates. Thinning causes the polymers to intertwine less and be farther apart when they lay down, leading to a much weaker coating.

Commercial jobs are often specified in a wet film thickness to achieve the rated performance of the coating (and to validate the warranty). I’m not always prone to consulting the manual, but I don’t have a chemical engineering degree, nor tens of thousands of hours of experience testing coatings in extreme weather chambers, so I’m inclined to follow the application guidelines on a can of paint.

[jack duren]

There’s a long time painter on another forum. There was a S&W commercial tech that joined the forum. They got into an argument about thinning, etc. when the argument was over , it was easy to see the painter was going to do what he wanted regardless what the tech suggested. Bottom line is the techs data is in a controlled environment and most painters aren’t working in that.

Problem I gathered is the painter is going to do what he wants as he see fit, regardless what the tech suggested. I lost respect for the painter..

[John TenEyck]

There’s a long time painter on another forum. There was a S&W commercial tech that joined the forum. They got into an argument about thinning, etc. when the argument was over , it was easy to see the painter was going to do what he wanted regardless what the tech suggested. Bottom line is the techs data is in a controlled environment and most painters aren’t working in that.

Problem I gathered is the painter is going to do what he wants as he see fit, regardless what the tech suggested. I lost respect for the painter..

I think that's more often the case than not, Jack. People will do as they want. Sometimes they don't know any better, and sometimes they do it even when they know it's wrong. The better course of action is to think just a little about what products will work with the equipment you have and that adheres to the manufacturer's data sheet. Of course, one does have to read the data sheet, or at least the back of the can. I strayed once on an interior job and thinned SW ProClassic 18% in order to get it to spray through the gravity HVLP gun I had at the time. There have been no ill effects in the 10 plus years I finished that piece, but the sheen definitely is lower than trim work I brushed with the same product. That project, and some upcoming paint jobs convinced me to upgrade to a pressure assisted HVLP gun and to look for products compatible with it; sort of a hybrid approach. That's how I found Emerald Urethane Trim Enamel. With 10% thinning it sprays beautifully and the sheen remains the same as a brushed finish. Same thing with BM's Advance.

John

[jack duren]

For the hobby painter I expect to do what is necessary to complete their project, for the professional I expect nothing less than to have the correct equipment to complete the task.

[Jim Becker]

What Jason wrote above is sound...he's worked as a pro painter and I've learned quite a bit from his posts over the years. John's advice has been similarly received and appreciated. One result of all of that is that I adapted my spray equipment to handle the finishes I use rather than adopting the finish to work with my equipment.

[Ken Krawford]

I don't have a larger N/N set. I was just wondering if that might be a fix going forward. So far the 1.8 set has worked well with all the paint I have sprayed.

You didn't mention you had a larger N/N set. Yes, of course, the higher the viscosity the larger the N/N needed to be able to spray something uniformly (without spitting and sputtering).

John