When choosing spray booths, woodworkers have two primary options: an open face or an enclosed paint booth. Here are a few things to consider.

Finish quality of the product
Controlling contamination in open face paint booths is difficult, especially in wider booths. To reduce contamination, woodworkers try to keep pre-finishing operations away from their paint booth. Still, contaminants are inevitable in an open face paint booth, as unfiltered air is pulled into the spray booth by the exhaust fan.

Open face paint booths are only available in crossdraft airflow; however, enclosed paint booths are available in several airflow styles, including crossdraft, side downdraft and downdraft. The style of airflow can have a significant impact on the quality of the paint finish.

With crossdraft airflow, air enters at the front of the booth, then flows horizontally through the spray booth, over the product and into a filter bank at the rear of the spray booth. As one product is sprayed, overspray may be pulled across products downstream, affecting the quality of the paint job.

Side downdraft airflow provides a consistent flow from each end of the spray booth. This is due to a filtered ceiling and exhaust plenums that run along both sides of the spray booth. The air flows downward, over the product and toward floor-level plenums, keeping overspray away from the product being painted.

Similar to side downdraft spray booths, enclosed paint booths featuring downdraft airflow achieve uniform airflow through a full-length, filtered ceiling and exhaust pit. Gravity carries overspray into the exhaust pit, making downdraft airflow the optimal airflow style for controlling overspray and contamination.

Paint booth size
The handling of parts in a woodworking paint booth can be cumbersome if the spray booth is not very wide. Open face paint booths are perhaps most attractive to woodworkers due to the flexibility in their dimensions. While traditional automotive and truck paint booths are typically deeper than they are wide, standard open face paint booths can range from 6 to 20 feet wide and can be purchased with depths of 6 or 8 feet.

Woodworkers with enclosed finishing paint booths often choose smaller models due to the added cost of filtered doors. In addition, adding doors on requires additional space considerations, including allowing floor space for the doors to swing open.

Price considerations
Open face spray booths are a more budget-friendly option than enclosed paint booths. Not only is the upfront cost lower, but they also require smaller and fewer fans, as well as fewer filters, since they do not feature intake filtration. Compared to equivalent-sized paint booths with crossdraft airflow, enclosed paint booths with downdraft airflow are about 25 percent more expensive upfront.

Ongoing operational costs are also higher for enclosed paint booths than open face spray booths. Downdraft enclosed paint booths require a significantly higher volume of air — about 20 to 40 percent more — compared to crossdraft open face paint booths.

Woodworkers who want to reduce contamination but do not want to pay the added costs for an enclosed paint booth may consider placing curtains on an open face paint booth.

Source: Global Finishing Solutions (GFS). For information call 800-848-8738 or visit GlobalFinishing.com.