Merriam-Webster’s online dictionary lists “blend” as a verb: “To mix (things) thoroughly and usually with good results.” A few synonyms and related words are listed, too: “combine,” “incorporate,” “mix,” “stir,” “conjoin.” Well, that’s not quite what we mean when we say “blend.”
Blend is also listed as a noun: “Something produced by mixing or combining different things.” And that’s not what we mean, either.
While we use the term blend in the paint shop as both a verb and a noun, it certainly isn’t either of the definitions we just read. My 1957 Thorndike-Barnhart dictionary mirrors Webster’s definitions, so I think we can reasonably conclude that the way we use the word blend in our industry isn’t due to generational differences. Nor can it be attributed to idioglossia or cryptophasia (that secret language between twins). But it’s fair to say that, to the outsider, the lingo we use is indeed cryptic.
We know what we mean when we say blend, though – getting into the adjacent panel for color consistency purposes. Creating the illusion of a perfect match by blending (verb). And it’s important that a painter can perform a nice blend (noun). I don’t want to oversimplify the blending process, but once a painter is in command of time-tested techniques and is faithful to the proper execution of them, then it is indeed pretty simple. However, before we talk about techniques, let’s consider the “why” of blending.
The most obvious answer to “why” is to help hide a color that’s slightly off. We aren’t going to go down the rabbit hole of color theory and tinting techniques here, but we will ask, “How do we know the color is slightly off?” We know because we’ve been diligently building our own personal color sprayout library, and when we pulled the appropriate color card out and determined that while it’s not dead-on, it certainly is blendable. Right? No? You don’t have a personal library? How about color chips from your paint manufacturer?
With or without the personal library or manufacturer’s color chips, we can be certain that nothing ever always matches. Therefore, we blend. It could be because the vehicle was repainted before, or it has a transparent color coat from the factory resulting in what appears to be a blotchy metallic that we’re probably calling “mottled.” Try and hide that “mismatch” without a blend. It could just be that UV exposure has degraded the hood at a faster rate than the less exposed fenders, resulting in two colors to match.
Let’s hope most of what we mix is not off due to a corrupt bank of toners – a failure to ensure all agitator lids are engaged to the bank and spinning several times a day. It’s possible that the formula has been altered or even completely overhauled and, as a result, is no longer going to work as the “go-to” formula for that particular color. We also can’t overlook the effects of metamerism, or the perceived difference of color due to different light sources delivering different light spectrums. Whatever the reason, the color is off, and we’re going to blend.
When Not to Blend
It’s important to note, however, that not all things can be blended. For example, a dark metallic flop on a silver vehicle cannot be hidden in a blend. Blending does not replace tinting and adjusting color; it complements it. In most cases, you’ll cycle the car through the paint shop faster by bringing the color to a blendable match and blending than attempting to match the color dead on. Not to mention that due to the differences of the cones in your eyes compared to my eyes, dead-on to me may not be dead-on to you.
Nevertheless, not every scenario is a candidate for blending color. Bumper covers come to mind. We need no reminder that most of the bumper covers we see on the road don’t quite match. We know that the color behaves differently between plastic and steel regardless of where you see the origin of the problem. Static electricity of the plastic affects the lay of the metallic, or the cooling effect of the evaporating solvent results in different temperatures between the substrates and therefore the painted steel parts take longer to dry than the plastic parts, which in turn affects the lay of the metallic. Either way, the metallic can behave differently between the substrates. Yet even with this in mind, it’s sometimes prudent to blend the adjacent panels when replacing a cover. There are colors that simply demand it.
Now hopefully we’re in agreement that, odds are, we’re going to blend the color. And hopefully we’re making that decision at the beginning of the repair process so we can maintain an efficient flow. It’s important that you refer to the technical reference manual provided to you by the paint manufacturer for specifics regarding blending their color. It will cover all the procedures and products necessary to maintain the integrity of their product – and their warranty. So let that be your guide as I present to you a few techniques for you to consider.
Another technique that makes metallic easier to control is a “wet bed.” Most of the systems I’m familiar with have a product that can be applied over the blend panel, and this gives a wet bed for the blend to lay on, minimizing any metallic halo at the edge of the blend that sometimes shows up with high metallic colors. Check with your jobber or technical rep to find the specific product to use. By the way, splitting the color and a wet bed – splitting both the base and the mid-coat at their respective edges – can help you when you’re blending a three-stage pearl or candy job.
As long as we’ve broached the subject of pearls, I would like to offer another time-tested tidbit.
Undoubtedly, you’re familiar with a “letdown panel” or sprayout card you made showing base color and one, two, three and four coats of pearl. Usually only half the card is cleared, and it’s used to compare to the vehicle to ascertain the proper number of pearl or midcoats you would need to apply to achieve a match. The challenge can be when four or five coats of pearl are needed to transform the base into a blendable match, and then you have to blend those four or five coats onto the blend panel without getting a halo of pearl to give your blend away.
Painting only a bumper cover is easy enough with no halo to worry about. But in the middle of a door? That’s more difficult. So I tucked away what a technical rep told me 20 years ago: “Tint your base so when you blend it out, it sort of looks done.” His point was to avoid having to radically transform the color of the base with several coats of pearl; adjust the base instead so you don’t have to.
This tip doesn’t really apply to factory candies – the ones where you have a semi-muddy orange metallic base you must transform into a bright and clean candy apple. No shortcut there. You have to make sprayouts and tint accordingly, but go ahead and split the color. That will help!
Another blending tactic is to utilize body lines to help hide the color transition. In addition, drawing the blend across the panel diagonally rather than vertically can assist in hiding the blend. Pardon the redundancy, but again, the color must be close enough for a blend to begin with; some mismatches simply will not blend out to achieve an invisible blend.
Before we get away from color, there’s another situation that can cause grief for a painter: seeing the edge of the sealer through the color. This can be common with waterborne, which when dry is so thin that it maps the sealer’s edge and it telegraphs to the surface. The practice of over-reducing the sealer in order to render it thinner and achieve a smoother surface is not recommended. That will result in an insufficient film build of sealer, which is one of the causes of sealer failure. A better solution is to mix and apply the sealer according to the manufacturer’s recommendation and melt the edge in with a blending solvent. When done properly, this eliminates a telegraphed sealer edge.
On to blending clear, or “burning” a blend in the clear or melting the edge in with a blending solvent as opposed to taking the clear to a natural breaking point. The answer is “no.” I know of no paint or car manufacturer that endorses that practice. They all predict failure if attempted, maybe not today or tomorrow, but in time as the edge of your clear blend will be revealed since it never melted into the OEM clear.
Yet, as a practical matter, there’s a difference between Grandma’s 1991 sedan (which has a scratch on the quarter panel that you’re painting for free) and a paying customer for whom you’re providing a warranty. The fact that you’re providing a warranty means you’ll want the paint manufacturer to stand behind their product, which demands that you follow their directives when using their products. So while you may have figured out tricks to facilitate the blending of clear, it’s not a sound practice. I guess you’ll have to work that out with Grandma.
What we’re aiming for here is increased production through improved efficiency, specifically in the paint shop. So let’s be proactive in anticipating the blends that will facilitate this, rather than creating a mismatch that will force us back into the booth.
|Splitting the Color
Decades ago, my father taught me a technique called “splitting the color.” When he was a young combo man, lacquer was king. He would sometimes cocktail the color with clear 50-50 for his final coats of color. He believed it better emulated the look of the factory lacquer, which was reflowed with high heat to improve gloss and minimize buffing. That works with lacquer because the color and clear are brothers.
With today’s coating systems, color and clear are not brothers, so we cannot mix them. But we can still split the color. Essentially, the result of split color is half the pigment suspended in a carrier of the same viscosity. The color, metallic or mica – everything – behaves the same as unsplit color but with only half as much being applied. It’s critical to maintain a consistent viscosity in order for the color to behave the same, which is why you cannot simply reduce the color with solvent. If you ever have, you know that the result is a different color as the metallic will behave differently than the more viscous color you’ve already applied and are attempting to blend.
Rather than using clear or solvent as the splitting agent, you use the same translucent product from your mixing bank that you use when mixing a mid-coat such as pearl. This is your splitting agent. Be mindful of any reduction you’ve done to your paint before you’ve split it, so you can maintain the same reduction after you’ve split it. Not to insult anyone’s intelligence, but this split color is applied at the edge of the paint you’ve already applied for coverage in order to transition your color into the car’s existing color. Of course, not all colors need this, but many will benefit from the technique.
Carl Wilson has been painting for nearly 30 years, with formal training from the GM Training Center, ASE, I-CAR and multiple product and color courses. He currently works as a technical rep for Hi-Line Distributors in Oahu, Hawaii. He can be reached at [email protected].