Why Do We Play With Our Coating Formulation?

    Posted by Mike Bonner

    Mar 11, 2015 2:32:00 PM



    In the last blog, I told the story of Dan, a friend of mine that runs a top-notch coating operation here in the Midwest and the problem he was experiencing during this extended cold snap we have been experiencing.  (Click here if you missed it or want to review)  In the end, Dan’s problem was caused by adding too much solvent in an attempt to adjust for the increase in viscosity caused by the colder paint temperature.

    Adding Solvent is Changing Your Formulation

    Most coaters don’t think about the fact that adding solvent to reduce the viscosity of their coating is fundamentally changing the formulation of their paint.

    But that is exactly what it is.

    I’ve never understood why we work so hard to develop coating suppliers we can rely on, work diligently with them to develop a coating solution that perfectly fits our customer’s demanding specifications, and then, at the first change in the weather, take it upon ourselves to alter that formulation by adding solvent “so it will run right”.  And then, just to compound the error, we blame them when this “new formulation” doesn’t meet the original specification!

    It seems a little absurd when you think about it that way, doesn’t it?

    So how can changing the formulation be an acceptable solution?

    The answer is:  It isn’t.  In fact, it’s a form of surrender.  It’s our way of admitting that there are factors in our carefully designed process over which we have no control and we just don’t know what to do about it.

    When Control Isn’t Control

    In Dan’s carefully controlled process, he has staged his coating on the floor in the coldest part of his warehouse and it got his coating function off to a bad start.  From there, it just spiraled out of control.

    So how can Dan fix it?

    He actually has quite a few options:

    • Change his Staging practices
    • Develop summer/winter blends
    • Install paint heaters

    The Issue with Staging

    The most obvious solution for Dan is to swap his staging around so he is storing his paint from floor to ceiling with the next paint to use at the top.  Seems simple. 

    But what about summer?

    When the temperature rises, the paint at the top will be the warmest.  What is Dan to do when its viscosity is too low?  While adding solvent to reduce viscosity is fairly straightforward, adding thickeners is not.

    OK, so what about staging the next paint in the middle?

    Better, but logistically complex.  Where does the newest paint go?  On the top?  On the bottom?  No, this is not an elegant solution.

    The Issue with Summer/Winter Blends

    This solution puts control over the formulation back in the hands of the experts – the chemists.  But since no good deed goes unpunished, it comes with trade-offs.  Now, you have to track two different part numbers for the same paint.  This often increases the cost by reducing the volume of each part number.  This can be a competitive problem because coating is a low-margin business.  Once you get past the cost ramifications, you have to manage the volumes very carefully to make sure that your winter blend does not carry over into the summer months and vice-versa.  This seems simple on an individual basis, but when multiplied by 500 – 1000 colors over the course of a year, it gets to be a real logistical nightmare.

    It’s All About Paint Heaters, Right?

    If you’re reading this then you probably already know that our business is viscosity control and that our preferred method of controlling it is through the manipulation of temperature – so naturally you’ll be thinking that I am going to suggest that this is Dan’s most logical course of action.

    But not so fast…

    There are a lot of things to consider when you contemplate installing any kind of paint heating system into your coating process.  To start with, as we’ve already established, coating is a low-margin business so Dan doesn’t have a lot of capital to play with – and these systems run from the tens-of-thousands to the hundreds-of-thousands of dollars – which ups the ante on this decision.

    There’s also the issue of safety.  Heating in an intrinsically safe environment can be tricky business – and a mistake here can be far more catastrophic than a few blisters!

    Then there’s that question of what to do in the summer…

    Heating only addresses the winter concerns.  Conventional paint heaters can offer, at best, a 6 month solution.  When temperatures climb in the summer, these simply can’t help.

    So, what is Dan’s solution?

    Stabilize Your Process to Stabilize Your Formula

    Obviously, the key to controlling any process is to stabilize all of the variables, and with a coating process, formulation is key.  Anything short of the optimal formulation is a compromise.  Of course, the performance of that perfect coating formulation is integrally linked to temperature, so stabilizing the process means stabilizing the coating temperature at its optimal point – all-year-round.

    It’s really that simple…

    Topics: Temperature control

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