HOW TO SPRAY

A T-111 Shed coated with Honey Gold stain has always been an iconic look in the shed industry. Things have changed and in recent years more and more sheds are being built with substrates that have a pre-primed surface. These new substrates offer a lot of advantages but one of the disadvantages is they eliminated the ability to get that rustic stain finish that many shed builders and customers preferred. True exterior penetrating stains are not made to go over a primer or lay on the surface. They were designed to penetrate and seal raw wood. Though we still see some builders using them over pre-primed substrates, it’s not recommended and can have some long-term durability issues. Waterbased Semi-Transparent Urethanes were developed to provide shed builders the ability to achieve a rustic stain like appearance over a pre-primed substrate. They also provide superior exterior durability when compared to acrylic paints or exterior penetrating stains.

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Therefore the Water-Based Urethanes have quickly become the premium type of coating for the shed industry. They do present one challenge and that is in the application. When visiting shops around the country we have seen that some have mastered the application, some still struggle with it and others have not started using urethanes because of not knowing the proper way to apply them. When applying a Semi-Transparent coating over a primed surface the goal is to make it “look” stained when in reality it is NOT actually stained. When applying the Semi-Transparent Urethanes you are wanting an even stained finish, no streaks, no dark spots and no sags or runs. To accomplish a quality “stained” look you have to adjust your application method from how you paint with a solid color.

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Below are some best practices along with pictures that should help you achieve the appearance you desire.

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Best Practices:

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• Change your tip size. For solid color paints most shops are using a 415 or 517 tip. These tips give you a wide fan but also provide a good volume of material, which is important when trying to cover/hide the surface. When applying the Semi-Transparent Urethanes we do not need as much material. We recommend using a 513 tip. This will give you a 10” fan and just the right volume of material. The wider fan helps you to overlap your spray pattern and achieve an even finish.
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• Spray with the grain. If the grain of your boards is running vertical then spray up/down. If you’re using lap siding and your boards run horizontal, then spray left/right. DO NOT SPRAY both vertical (up/down) and horizontal (left/right) on the same surface. If you spray in multiple directions, you will end up with dark stripes and an uneven finish. For example: when you come to windows or doors, continue to spray the same direction. Do not change to left/right spray for those and use an up/down spray for the walls.
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• Overlap your spray pattern. Whether spraying up/down or left/right it’s important that on each pass you overlap the previous pass 50%. This technique will help eliminate light spots and streaks.
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• Spray in to or towards the corners/edges of trim boards. Keep your pattern of vertical or horizontal spraying (not both). But only spray in or towards the trim pieces not all the way across. For example, if you have a trim board running horizontal across a gable end. If you spray vertical up to HOW TO SPRAY SEMI-TRANSPARENT Water-Based URETHANE and across the trim board you will create a light area or “halo” above the trim board which becomes difficult to hide. By just spraying up to the bottom side/edge of the trim and then spraying down to the top side/edge of the trim you can eliminate the “halo” effect.
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• Practice First. If you are new to spraying Water-based Semi-Transparent Urethanes it is best to practice on scrap boards to get the technique down before you coat a full shed.

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We hope you find this article useful and it will improve the quality of your paint process. Please reach out to your local Pittsburgh Paints Tru-Industrial Specialist to further discuss painting tips. If you would like to view past issues, please contact Sharon Bird at sheds@pittsburghpaints.com.