Re-Dyeing Leather

by Kian Amirkhizi & Doug Snow

The artist has his brush, the sculptor his chisel and the interior restoration technician has a spray gun. You might think that the modern spray gun is just the marvelously engineered device that permits the efficient atomization of pigmented particulates. However, it’s much more than that, it’s the pivotal apparatus that transcends the technical underpinnings of vinyl repair to the artful science that it is. And the technician’s Paint Pistole’ prowess is generally the area that separates the expert from the novice. Improper spraying technique is the cause of all sorts of issues; some immediately recognizable and other problems may take a while before they surface.

This final and highly critical step for the successful completion of the “dye job.” If you have followed the first two articles in the series, you’ll remember that in part one we learned about the proper preparation of the substrate, part two was all about the repair process, and in this installment we will cover the application of coatings.

Equipment

Through the years I have tried just about every conceivable contrivance for the application of coating materials. Airbrushes, HVLP, sponges, wiping cloths, conventional spray guns, turbine systems, air compressors, CO2 tanks, compressed air canisters, you name it—I’ve tried it. All the above methods may produce excellent results if approached thoughtfully. But before we can judge the results we must first have a goal or a target. For some the goal is simply to paint the surface of the material as quickly as possible—blow and go. But for the few who are interested in excellence, every part of the process contributes to the results of the whole.

However, as it usually goes in all things of this business, there is a method that if used consistently produces superior results. Through my many trails, I have found that the turbine spray systems are the best for the application of water-based coatings. This is due to their unique design, which allows high efficiency transfer. The turbine spray system cycles a high volume or quantity of air through the gun, but with very little pressure. This allows you to “lay” the paint on the substrate without overspray or dry-spray. There can be many causes of dry-spray, which we will investigate later in the article. In this case, dry-spray is a condition that occurs when paint dries prematurely as it moves through the air. This usually happens when pushing the atomized paint particles too fast, thereby creating friction and heat, which evaporates the carrier: water. Thus instead of having a paint you create dust. Dust does not make for a great coating. Especially when you spray over the dust that ends up falling onto the surface and then you cover it with more paint. This causes an uneven texture that is readily detected when running your hand over the surface.

Coating Selection

Where do we start? There are myriads of coatings available on the market today. Choosing one can be more frustrating than standing in aisle six of your local market and trying to pick your wife’s favorite brand of “feminine protection.” Sorry ladies, there are just some things that you shouldn’t ask a man to do. So, instead of making specific recommendations on what you should use, I am going to invert that logic and tell you what you should not use. Do not use coatings that have not been specifically designed for leather. Commonly, these are solvent-based vinyl coatings, which come in spray cans. These coatings may look fine at first but they do not retain the requisite physical requirements to endure the unique stresses of leather.

Problems & Solutions

There are plenty of things that can go wrong if you don’t follow the proper procedures during the refinishing process! Here are some common problems that generally plague beginners and even seasoned professionals.

Dry-spray

The most common complaint, “it just feels rough, like sandpaper.” The two causes are inferior or poorly operated equipment and lousy application techniques. I have observed many technicians who do not maintain their equipment properly. A spray gun requires the uninhibited flow of air. That is not possible when it’s obstructed by dried debris from your last three jobs. Unless the gun is performing perfectly you should expect less than perfect results. Shortcutting the cleaning and maintenance of your equipment will produce unsatisfactory results and may actually increase the amount of refinishing time. Also, a critical point is that even if your gun is completely clean, you will discover that very soon after you start spraying a conglomeration of material will develop right at the exit point of the needle. This is crudely referred to in vinyl repairman’s nomenclature as a “booger,” and this “booger” needs to be removed. Usually by picking (sorry—couldn’t help it) the accumulation off with your fingernail is sufficient, but there may be times when more drastic action in necessary. I have found with the assistance of a wooden toothpick (always close by) can facilitate the easy and effective removal of the “booger” without damaging the delicate nature of the spray gun. You should never use a metal object in clearing debris as it may deform the nozzle and needle. Additionally, you may also use a brass-bristled brush to scrub the tip, which works nicely as well without the hassle disassembling the gun.

Spray technique

Whenever you are spraying a seat, you should mentally consider each panel of a seat as a separate section, to be sequestered and sprayed apart from the rest of the seat. This allows an even coat over the entire seat. This also allows the coating to flow. Flow is where the coating is applied wet enough to allow the coating to meld into each successive spray pass. The flow is essential to keep from creating the dry sandpapery texture that is all too common for most technicians.

Keystoning

This is a situation where the technician does not maintain the gun at a constant 90 degrees from the substrate when applying the coating. When this happens, the side closest to the substrate ends up with the heaviest application of coating. A consistent thin coat is essential for proper coating technique. This happens quite often when spraying around seams or on awkwardly shaped materials.

Coating too heavy

Oh, I love this one. When I see this I certainly know that I have no competition to worry about. This is caused when a technician has no finesse coupled with a heavy-hand (a.k.a. blow and go). The fallacy of the logic is expressed as, “If a little is good than a lot is better.” It’s kind of like eating too much at a Thanksgiving dinner. You usually don’t pay the price of gluttony until much after the indulgence has occurred. A closer look at leather reveals why this is not a usable strategy in the refinishing process. Leather moves uni-directionally. Unlike a textile or vinyl that has a weave of fabric incorporated into design there is no directional mesh innate to leather. The unique fiber structure of leather gives it the ability to move and stretch in any given direction no matter the demands. This is necessary to distribute the pressure presented on the surface of the leather, extending the load over the entire network of fibers. If you even slightly inhibit this process you create an unnatural restriction of the natural movement of these fibers. This creates a condition know as “old lady skin” or the new PC version “elephant skin.” In years past, I have always wondered why that after a seat was coated it prematurely hastened the aging process. It seemed that after a year or so the seat would look severely weathered, with deep creases turning into cracks in short order. This condition of premature ageing also created much of the unpopularity that “dye-jobs” seemed to acquire by the general public and some car dealers. Specifically, the heavy coating restricts the natural movement of the fibers and consequently focuses all of the friction into concentrated areas. And since leather is a physical thing with mechanical movement it simply wears out.

Overspray

This is caused by one thing—laziness! Interior restoration technicians are notorious for depositing mass quantities of unwanted droplets of color all over the most readily visible parts of an automobile’s interior. This can really turn into a sticky wicket! (Although no one has ever seen a “sticky wicket” they are believed to be very difficult to deal with.) Generally, if you get a little overspray when using a water-based coating you can get it off with just a little all-purpose cleaner and the gentle pressure of a micro-fiber cloth. However, if you crosslink the coatings and you don’t get it off any unwanted surfaces immediately, you may risk permanent attachment. And the use of powerful solvents in aiding the removal process will most likely result in the damage of the plastics or dash pieces. Especially when there is lettering involved such as the silk-screened identifiers that are all too common in automobile interior panels. A couple of purchased replacement parts can be an expensive lesson to learn.

In conclusion

Anybody can paint, if they have a few fingers available to articulate a paintbrush, just as anyone can re-dye a seat, provided they have a hand to hold the spray gun. But it takes an artist to create a painting that is pleasing to look at and that is exactly the case with the “dye-job.” It truly takes an artist to create a masterpiece! Okay, a little over-dramatic, but the commitment to excelling at this critical stage in the restoration process cannot be overstated. It definitely takes time and patience with an eye for recognizing what is acceptable and what is not.

It takes careful preparation in preventing overspray. It takes the proper selection of coatings for the particular substrate. It also requires time and experience to give you the necessary instincts. Attending a training seminar may speed up the learning curve and give invaluable insights to the process. But the restoration game is a puzzle; all the pieces come together to form a picture. If a piece is missing, the picture is flawed. Learn to master all the steps, completely!

Kian Amirkhizi and Doug Snow are the founders, primary instructors and owners of MATRI-X, a company that provides professional training and supply for the repair and restoration of leather, vinyl, plastic and velour. Both Amirkhizi and Snow are nationally recognized experts in these disciplines, and have won several national awards. Both continue to operate their own successful restoration/repair businesses in the Los Angeles area.

Your feedback is welcomed, so please do not hesitate to contact them with comments regarding this article at MATRI-X at 888.207.6007. For more information on product suggestions, please contact them online at www.reconsupplies.com.