Preval Sprayer

Audrey and I enjoy working on and restoring small boats. An oft-repeated task is the application of coatings, and one of our favorite tools is the Preval Sprayer, a versatile and portable aerosol spray gun ideal for applying finishes to small areas or complex surfaces like the interior of a lapstrake hull with closely spaced frames, or when just a touch-up is required. We first learned about it through an informational video put out by Jamestown Distributors, and later got a strong endorsement of the sprayer’s versatility from a friend who runs a marine repair business.

Photographs by the authors

The Preval Sprayer components can be purchased separately, but we have found the Valpack to be comprehensive and cost-effective: it includes a complete sprayer with extra power unit, several reservoir jars with extra caps and tubes, and a vGrip Universal Handle.

The Preval Sprayer can be used with oil-based, polyurethane, and latex paints, varnish, and even polyester gelcoat. The sprayer consists of a power unit and a reservoir. The power unit is an aerosol can that contains 1.94 oz of propellant (a mix of dimethyl ether, isobutane, and propane)—enough to spray 16 oz of liquid at 70 psi. The top of the power unit has a finger-operated spray button, and the bottom has a screw cap and siphon supply tube with a nylon filter on its end. The tube comes in two lengths and the power unit can be screwed onto either a 2.9-oz “touch-up” reservoir or a 6-oz reservoir. The reservoirs are available in plastic or glass, are reusable, and come with their own screw-on caps. Both the plastic and glass reservoirs are solvent-proof, and the glass ones are also shatterproof.

Painting with the Preval Sprayer

Using the Preval Sprayer is straightforward. Strained and thinned paint is poured into the reservoir—filling the jar no higher than its shoulder—which is then capped and shaken. Next, a supply tube is inserted into the bottom of the aerosol, the cap is removed from the top of the reservoir, and in its place the power unit is firmly screwed on, the supply tube setting down into the paint. With that the sprayer is ready to use.

The Preval Sprayer is very portable and can be used in small spaces. It can be operated at an angle of up to about 45°—as long as the end of the supply tube remains immersed—but beyond 45° liquid can flow out of the power unit’s vent. The supply-tube filter is recommended when using thinner liquids but can be removed for thicker liquids. Some coatings must be thinned, and the user’s manual offers baseline thinning guides and coverage estimates for commonly used finishes.

We have found that the spray comes out of the nozzle at a steady rate and the flow is easily controlled either directly with a finger on the spray button, or with an optional vGrip Universal Handle, which comprises both a pistol grip and trigger. We like the vGrip as it gives us better control, is less tiring on the fingers, and keeps our fingers away from whatever finish we’re spraying.

Spraying at a distance of between 8″ and 12″ from the workpiece gives the best overall result: any closer and sags can develop, farther away and incomplete coverage shows up as a pebbled finish. We find that varnish lays down more smoothly with the sprayer than with a brush or roller and, with no need for repetitive brush strokes, it’s a lot quicker to apply. However, since the varnish is thinned more coats are required, and the thinner knocks down the gloss a bit. We prefer a satin finish, but for a high-gloss look a final coat could be applied with a brush or using the roll-and-tip method.

Cleaning the Preval Sprayer

Cleanup is easy. The reservoir is separated from the power unit, which can be flushed out with a compatible solvent and reused. Solvent (or water for water-based coatings) should be sprayed through the system for at least 10 seconds. Compared to cleaning brushes, much less solvent is used, and the cleanup process is considerably faster. If any liquid remains in the reservoir, the jar can be capped and stored for future use—a considerable advantage when compared to coatings left over in a cup during conventional painting, which cannot be poured back into the can. If the finish is all used up, the jars are easy to clean—again, with compatible solvent.

As our handle shows, we have used the Preval Sprayer for varied finishes and have had good results. The sprayer can be used without the handle, but we appreciate the extra control it offers.

Power units and reservoirs for the Preval Sprayer can be purchased separately from hardware and online stores, but we purchased the Valpack kit directly from Preval. The kit includes one complete unit—aerosol, reservoir, vGrip handle, and siphon tube—plus two replacement power units, and an assortment of reservoirs, caps, lids, and tubes. It has proven to be excellent value, and just the right size for our small projects.

Audrey (Skipper) and Kent Lewis mess about in the creeks, rivers, and bays of Virginia’s Tidewater Region with their tiny fleet of 16 boats. Their adventures are logged at smallboatrestoration.blogspot.com

For more on how to achieve a great paint finish, see Kent and Audrey’s article “Using the Roll-and-Tip Method,”  and our Fitting Out Guide on how to achieve “A Smooth and Level Painted Finish.”

The $62.99 Preval Valpack and all replacement parts, including power units—$7.99 for singles, $82.45 for a 12-pack—are available from Preval.

Is there a product that might be useful for boatbuilding, cruising, or shore-side camping that you’d like us to review? Please email your suggestions.