This is the question, I and those in my profession, struggle with more and more every year.

Back Story: The Air Quality Management District, (www.aqmd.gov) is a California State agency empowered to reduce pollution in our state. As long as I have been practicing this trade of Wood Finishing I have dealt with new materials reformulated to comply with ever stricter regulations implemented by the AQMD to reduce volatile organic compounds, (v.o.cs.) in paint, clear coatings, the solvents used to reduce these materials and for clean up after use.

It is these v.o.cs. that allow solvent borne materials, (and to some extent water borne materials) to flow out onto the surface properly. In addition, they promote fast dry / cure times. They are also a prime contributor to pollution and in particular, ozone in the air we breathe. Hence the mandate to reduce v.o.cs. It should be understood that there are few usable zero v.o.c. paint and or clear coatings at this time. This includes water based paint and clear coatings as even they emit v.o.cs. as they dry.

History of Material Use: When I began practicing this craft of wood finishing thirty years ago, I never thought too much about the chemical makeup of the material. The goal was to produce a furniture grade finish that would hold up to average family use in kitchens, baths and furniture. We used nitrocellulose lacquers. They held up well, looked like furniture finish and were easy to use.

It was in the late eighties that the AQMD began to mandate reformulation of paints and clear coatings to reduce v.o.cs. It soon became clear that the reduction in v.o.cs. compromised the wear and tear / durability of these materials. In addition, this reduction greatly degraded the ease of application and use of these products. At that time, I began trials and experimentation with new and different clear and paint coatings that continues to this day.

The initial change in our production coatings use was to upgrade to acrylic lacquers with the use of vinyl sealers. Over the years, we have tried many different alternative finishes. These finishes include water based lacquers, water and solvent borne conversion varnishes, catalyzed polyurethanes etc. However, nothing has thus far duplicated the thin transparent, durable and easy to use lacquer that was in common use thirty and more years ago.

Impacts of Recent Reformulation: In the summer of 2006, the AQMD mandated the most drastic cut in v.o.cs. to date. Limits were set at less than half their previous level of 570 grams of v.o.c. per litter to 275. Many of the paint manufactures had not done enough research and reformulation to achieve satisfactory results at these levels. In some cases, the new materials were unusable and wear and tear / durability was drastically reduced yet further.

To the consternation of the homeowner / end user and applicators / wood finishers, painters etc. these finishes have required far more maintenance and touch up work than should be reasonably expected.

Reaction / Action: Due to these issues with the degradation of these materials, we at Thomas Craven Wood Finishers have greatly stepped up our research and trials of new materials. This effort has led us to the manufactures that are making the greatest commitment to the R & D that is leading the way to improved performance in not only the wear and tear but also the appearance of these materials.

It is this commitment to change and the hard work required that will result in I believe better materials in the long run with little or no pollution. While others in my industry resist the changes made, we embrace them. I have always staked my reputation on the quality of the finish we produce. Not only the appearance but also how well they hold up to the everyday wear and tear of family life.

Attitudes Toward Change: I have heard many viewpoints both positive and negative regarding these mandated materials changes and in fact, many of my peers / competitors have chosen to resist the changes. Some choose to import illegal materials from Mexico or from states that do not have regulations in place as the State of California does. Others have chosen to close up shop and exit the field altogether for other perceived easier careers / business.

My position with Thomas Craven Wood Finishers has always been to embrace these and all other changes and in fact be the forerunner of change. It is only through open-minded experimentation with changes in materials, working practices and attitudes that we achieve growth for ourselves, the community and world.

The inspiration for this attitude on my part comes from my memories of growing up in the heart of the San Fernando Valley in the ′60s. On bad smog days, we could not see the surrounding mountains that ring the valley. If you breathed deep and or exerted yourself greatly on those days, it would hurt your lungs.

Today it is rare that we are unable to see the surrounding mountains and I cannot remember having a difficult time breathing since those years of the ′60s.

Excerpted from the AQMD Website: Air quality in this area has continually improved despite an enormous increase in population and cars. For example, maximum levels of ozone, one of our worst smog problems, have been cut to less than one third of what they were in the 1950s, even though today we have nearly three times as many people and four times as many vehicles.

In the past decade, we have virtually eliminated Stage I smog alerts, the level at which schools are advised to keep children from playing outside. We have not reached Stage II levels, which used to occur 100-120 times a year, since the 1980s.

Relevant Analogy: When talking to people regarding the constant flux, confusion and frustration with wood finishing materials in use today, I use an analogy to put this point in time into perspective. That is, the federal government mandated catalytic converters for cars in the early ′70s. Everybody complained about the lack of performance of their cars and reduction in gas millage. Today after massive amounts of money spent on research and development by the auto industry to reduce emissions we have cars that far outperform the cars of the ′70s with greater horsepower, almost double the gas mileage and very near zero emissions. The only downside of this process has been that we all pay a lot more money for cars now !

The auto industry had much deeper pockets, (back then) to fund the R & D necessary to implement the mandated changes than the paint manufacturers of today do. However, we need to keep in mind that the changes mandated by the AQMD are for the state of California only. If we had federal regulations, matching the stringent requirements mandated by the state of California the paint industry would be spending much more money to implement these changes.

Conclusions: The important changes are coming. However, it will take time to perfect the materials to achieve satisfactory results. We have had success in the last twelve months implementing the use of new and stronger materials. Yes, they are more money. However, I think it is worth the money for a cleaner environment to breathe and live in.

I remember the 2008 Olympics in Beijing China and seeing the smog on the broadcasts that the Chinese government tried to hide and downplay. I am glad that we in this country and this state made the commitment many years ago not to live like that.

We at Thomas Craven Wood Finishers are dedicated to the task of determining which of these materials work the best and under what conditions. We will always be committed to spend the time, money and effort to achieve the furniture grade finishes, that hold up well as you have been accustomed to from Thomas Craven Wood Finishers.

© Copyright by Thomas Craven June 2009 ©

All spray systems attempt to achieve one thing, that is atomization. Atomization from the dictionary is to, “reduce to minute particles or to a fine spray”. Whether you chose conventional, HVLP, or airless spray equipment, they all achieve the same thing; that is atomization. A satisfactory finish is produced when the spray material is atomized to the point that the material will flow onto the surface and become a uniform and even coating.

Viscosity and pressurization are the two main factors that effect proper atomization.

I looked up the definition of viscosity in the dictionary and found it to be just as hard to understand as the name itself. So I will tell you my definition of viscosity as it relates to spray finishing. Are you ready for it; it’s how thin the material is! Correct atomization occurs when the material being sprayed is just viscous or thin enough that the pressurization provided by the spray equipment in use can break up or vaporize the particles to produce a satisfactory coating. You only thin the material down enough so that your spray equipment will atomize the material while producing a coating that flows out onto the surface. Thinning the material too much will leave a coating that is spotty and runs down vertical surfaces. A coating too thick that is drying to fast will give you dry, rough areas and orange peel.

Now that we have our material correctly reduced; how do we then atomize it? By pressurization. It is the air under pressure coming out of the front of an air gun that breaks up the material. Or in the case of airless spray equipment, it is the pressurization of the material itself in the spray line that is then forced out the front of the gun through a very small orifice or spray tip that causes atomization at the front of the gun.

Spray Equipment

Conventional – High-Pressure, Low-Volume air spraying is out dated technology. Rarely in use inCalifornia any more. Produces a lot of over spray and hence wasted material. Material is presented at the front of the gun where air ports in the air cap at the front of the gun introduce a low volume but high pressure, (40 – 60 psi.), stream of air into the material to break it up and create a variable fan pattern.

HVLP – High-Volume, Low-Pressure, is the standard equipment in use today inCalifornia. It atomizes the material in the same manner as the conventional gun, by introducing a stream of air into the material that is presented to the front of the gun. However HVLP guns use a larger volume of air at a lower pressure typically 10-20 psi. Reversing the relationship between pressure and volume. This system decreases voluminous over spray and saves materials.

Compressors and Filters. Both of these spray systems need compressed air to operate. This air should be filtered as the action of compressing the air heats it up. While in the tank and hose, this air cools down. The moisture in the air then condenses in the tank and lines. In addition compressors will inject oil and other contaminants into the air supply. An oil and water separator / filter mounted close to the end of the airline is recommended. The compressor should be installed outside the building whenever possible. Remember it will be drawing air from the surrounding area you install it in and blowing it on your work.

Spray cups / guns and spray pots.

A siphon cup gun has a one-quart cup attached to the bottom of the gun. When you pull the trigger on the gun, air is released out of the air ports in the cap at the front of the gun. This air stream siphons / pulls material out of the cup. The vent hole at the top of the cup must remain free and clear to allow air to enter the cup so that the siphoning action can take place.

A gravity feed cup gun is a new innovation in cup / gun design. The cup is mounted above the gun so that the force of gravity is used to bring the material down and present it at the front of the gun. You must keep the vent hole at the top of the cup free and clear to allow the material to drain into the gun. It is superior to the siphon feed cup gun design. Both siphon and gravity feed cup guns are best used for small amounts of material. Sample work, shading and toning procedures, etc.

A spray pot is a two-gallon or sometimes five-gallon pot or bucket that has a pressure regulator attached to the top of it. The regulator allows air to free flow through to the gun to atomize the material, but it also pressurizes the material in the pot. Instead of passively siphoning or allowing gravity to feed the material to the front of the gun, the spray pot will deliver material under pressure to the front of the gun for atomization to take place. This will allow greater production as less air is needed to atomize more material. In addition greater capacity is provided by the two or five gallon quantity of material in the pot.

Airless spray machines use a hydraulic pump to pressurize the material that is sucked up in a pick up tube from a five-gallon bucket. The material travels in a ½” diameter spray line that is available in fifty foot lengths. The material is forced out the front of the gun through a very small orifice or spray tip. This spray tip atomizes the material and shapes it into a spray fan of preset widths 3 to 21 inches wide.

Air assisted airless is a hybrid system that combines the low pressure high volume air only atomization of hvlp systems with the high volume delivery capability of airless spray equipment. The material is atomized first by a single orifice spray tip under pressure. Further atomization occurs via an air cap on the end of the gun that introduces air into the material stream. The advantages are less over spray than conventional or hvlp systems with greater material flow and transfer efficiencies like pure airless systems.

The big advantages to airless spraying are, 1. Dispensing with the need for compressed air to atomize the material. You get straight material coming out of the gun without the cold, damp, dirty air that is delivered by most compressors. 2. A uniform spray pattern delivering a consistent amount of material all the time. This spray pattern does not require constant adjustment like the conventional and HVLP guns do. 3. It is a closed airtight system so that you may leave material in the spray rig and bucket for extended periods of time. 4. Only one material line too the gun allowing for more mobility. Excellent choice for high production shops.

Spray Techniques

Spray finishing skills take a lot of raw gun time to be proficient at. You can speed this process up with proper training and coaching. A very simple concept I express to my spray man trainees is; Spray until the surface just gets wet, no more and no less. If you spray too dry, the material won’t flow and will be rough. If you spray too wet, it will run and fall down vertical surfaces or pool and puddle. Your goal is to get the material to flow and become one even uniform coating with no orange peel, dry spots, runs etc.

Always start from the up wind end of the work and spray away from you towards the face of the booth. You don’t want to spray into the airflow of the spray booth as this will leave over spray on previously finished parts and the spray man too. Shoot all edges first and try to shoot your best surfaces last.

Cabinet boxes should be shot from top down, working from inside out and horizontal surfaces last. Start and stop your spray movement before and then after you get to the corners. This will allow your over spray to fill in the corners. Do not spray all the way into the corners of a box.  This usually results in to much material deposited in the corners and the ensuing dreaded runs.

Lapping the material. The general rule of thumb is to overlap your spray pattern by 50 %. This is not set in stone. It can vary depending on the speed you are moving your spray hand. Just remember the basic principal. Spray until the surface just gets wet, no more and no less. Be sure to overlap the leading and trailing edge of a panel to apply a uniform coating to the edge.

Six to eight inches away? Again this is a rule of thumb that is not written in stone. Hold the gun the distance from the surface that produces a coating that is just wet.

Watch the material coming out the front of the gun. Don’t watch the gun or the surface you are spraying. Keep your eye focused on the material flowing out the front of the gun. This technique gives you a better perspective on how much material is being deposited on the surface.

© Copyright by Thomas Craven November 2008 ©

This is another exceptional buffet cabinet we have recently completed for a client. Antique, handmade and hand shaped, heavily distressed mahogany buffet with Malibu Tile inserts. The client delivered it to us, asking to make it darker than it already was which was almost black. The steel hardware was rusted. As we washed the existing color off, I could see the beautiful color of the underlying wood tone. I convinced the owner to finish it lighter with a dark glaze absorbing into the distress while highlighting the details and hardware.

This is a beautiful buffet cabinet we have finished for my good friend at JKF Cabinets of Simi Valley, Jon Flugum. The top is lightly distressed. Stain and glaze color treatments. Finished with satin clear conversion varnish top coats. The base was stained black. Hardware, (hinges and handles) were painted black too. It was then painted white. Distressed and lightly sanded back on the edges and details to reveal the black wood tone underlying. We then applied a light raw umber glaze to shade, highlight and antique the white paint and darken the distressing. Finished with satin clear conversion varnish.

I wanted to take the time to congratulate you and your team’s excellent conversion of a raw alder wood cabinet into a duplicate of a finished maple cabinet purchased long ago from a discontinued manufacturer. Many other local finishers had viewed the same sample I provided to you and summarily rejected the job as being too difficult, but you were able to visualize the required process and achieve the desired result. Many of my neighbors have had a chance to look at the originals and your finished cabinet and they cannot tell the difference between the two even though you only promised to get “close”.

The biggest critic on the planet is my wife, who is so pleased she’s been calling family and friends to show them the result.

Again, thank you very much. It was a pleasure to do business with you.

Regards,

Brian Reynolds
Director, Quality Assurance
brian.reynolds@xirrus.com

Xirrus
2101 Corporate Center Drive
Thousand Oaks, CA 91320
http://www.xirrus.com

805.217.2230 (mobile)
805.262.1631 (office)
805.262.1601 (fax)