Best Products to Thin Wood Stain. By considering your application equipment, technique, where you spray, and characteristics of your polyurethane, you can ensure that you will apply your coating in a more efficient and better appearing way. If thinned water based products are stored, they will separate and lose the semi-gel consistency. However, you’ll build thickness by applying multiple thin coats. There are a lot of myths floating around about how to thin polyurethane, and the benefits it provides for bonding. Click to see full answer. You may also need to add thinne… I’d suggest acetone. FFLP208 tip, 2000psi. Fill the cup with thinner and spray thinner for about 10 seconds. With the varathane, I usually had to thin 10% with distilled water (don't use tap water due to the minerals in tap water). The easiest way to know whether or not you may need to add thinner is by trying to spray the material without any thinner being added. In between different coats of polyurethane, you should sand (with about a 220 Grit sandpaper) to provide a better surface for the next coat. Add the polyurethane to the container and then add half that amount of paint thinner. If you will be using a water-based polyurethane, you want to raise the grain and then sand it down prior to applying your first coating of polyurethane, this will help prevent raised grain which can create an ugly finish. To be clear, most of these myths are untrue, and thining poly does not create a stronger bond. In between various coats of polyurethane, you will want to sand (typically with about a 220 Grit sandpaper) as this will help provide a surface for the next coat of polyurethane to adhere to. If you’re looking for the highest production of the options,  will want an air assist airless spray outfit. Rust-Oleum Varathane Polyurethane Spray is the best scratch and stain resistance coating for interior wooden surfaces. Forum Responses Naphtha dries (evaporates) much faster than mineral spirits (paint thinner). A thin coat will help to reduce or eliminate issues such as runs in the finish. Brush flat surfaces with a thin coat using a bristle brush. If you want something really slow, you can use kerosene. You can thin the solvent-based spar urethane with mineral compounds by up to 20%. Work with the grain, and avoid applying too much polyurethane to avoid raising the grain. Aside from that sage advice, I would recommend that you get a waterbased poly (acrylic or urethane or both) and rent a little turbine HVLP to lay it down. When you are finished, remove the cup and pour the remaining polyurethane back into the can. Then after suitable drying time, I spray subsequent coats using a 75% poly/25% mineral spirits blend. September 14, 2006. Additionally, you can typically expect a longer time to complete the coating application due to longer dry times. Wipe contoured surfaces with a clean cloth, going with the grain. 10.3 When Spraying Polyurethane, can an Airless Sprayer be used? The best guidance will be your coatings technical data sheet and how the coating is spraying visually. What can I use to thin the poly to get a good laying finish? Hi Kerry, I've used the Varathane water-based a number of times but have sinced moved on to spray lacquers. Due to polyurethane being a thicker coating, you may need to use thinner to reduce the material’s viscosity so that it can be sprayed well. Tread lightly when using a … How To Thin Polyurethane? You can thin it. Polyurethanes are typically slower drying coatings in comparison to other wood protective finishes. If while trying to spray the material without thinner you get large clots or orange peel appearance in the finish, you’ll typically want either to consider adding thinner or trying a slightly higher air pressure. Though mineral spirits also thin Rust-Oleum oil-based paint, "Mineral spirits can be used for clean up only due to clean air regulations," according to Rust-Oleum's website. When you use the spray polyurethane you do not have to worry about brush strokes or fibers from the brush being in the finish. Choose the type of paint that you will be using. 10.1 Do you Need to Thin the Polyurethane before you Spray? How was the gun set up? What type of thinning ratio and air pressure should I use? If you are looking for the greatest versatility at a lower price as far as being able to spray polyurethanes along with paint or even glue, you typically want to consider a conventional spray gun. Thinning of polyurethane will vary depending on a variety of factors, but typically thinning can require 10% or more thinner to achieve a thin enough polyurethane for spray applications. 10.2 How do I Apply the Polyurethane Coating? You can thin the polyurethane out the same way you would thin paint out. You can also thin solvent-based poly by adding up to 10 percent mineral spirits, but only if you live in a state that allows it. Apply a THIN coat of Minwax® Fast-Drying Polyurethane using a high-quality natural or foam brush. I have a customer who has specifically requested a sprayed polyurethane finish. However, spraying provides a lot of benefits that may make it worth considering when applying polyurethane, especially if you plan on applying a high volume of polyurethane. Oil-based varnish, including polyurethane varnish and oil paint, can also be sprayed, of course, because any thin liquid can be sprayed. In addition, if you select a spray gun, you want to consider how you feed material to the spray gun. A super simple way to thin polyurethane is to use mineral spirits. You do have to worry about applying the polyurethane so that it is in thin coats that dry quickly and so … Please note for certain product categories particularly filters there is at times an additional charge for shipping. Slight thinning and a fine bristled brush with good … The most common options include via pressure, gravity, or suction. These finishes dry fast, sometimes too fast in warm temperatures to successfully brush onto large surfaces. This is not entirely the case. Question If while trying to spray the material without thinner you get large clots or orange peel appearance in the finish, you’ll typically want either to consider adding thinner or trying a slightly higher air pressure. The ratio isn’t crucial. I use a conventional Spartan spray gun, no HVLP or LVLP yet. Is Spray Polyurethane better than brush? Epoxy resin varies from brand to brand but, on average, there is a 35% decrease in its strength properties of the epoxy for ever 5% of thinner added to the mixture. Like all varnishes, oil-based polyurethane dries in two steps. This leads many to believe that thinning polyurethane with naphtha will make it dry faster. You can learn more about whether HVLP or Air Assist Airless would be better for your application by reviewing this guide here. The easiest way to know whether or not you may need to add thinner is by trying to spray the material without any thinner being added. Have you ever tried spraying your own polyurethanes, and if so what have the challenges been? Due too polyurethanes being a heavier body coating, we would recommend considering a pressure fed spray gun. The initial coat should be dry within a couple of hours, and you can then apply a second coat. My method is to thin the poly 50/50 with mineral spirits for the first 1 or 2 coats. Since 1947 we have served as the experts on surface preparation and coating application equipment. To achieve the protective performance of polyurethane, you want to build the coating thickness up. Michael Dresdner: Use a fairly thick, fast-drying polyurethane, and thin it 50/50 with acetone (instead of mineral spirits or naphtha). Brushing a rounded, contoured or vertical surface is more likely to create drips. Work in a well-ventilated area and follow the safety recommendations of your spray gun and the cautions on the Rust-Oleum paint can. To get the best finish when spraying polyurethane, you should try to apply a thin coat (as thin as possible). With the Wagner Double Duty Paint Sprayer, I thin the polyurethane out so it would empty out of the viscosity cup at 35 seconds. After all, polyurethane is often a little bit of a thicker coating when compared to other protective wood finishes like lacquers. Thinning oil-based varnish and polyurethane The thinner to use for oil-based varnish and polyurethane is mineral spirits – 3 or 4 parts varnish to 1 part mineral spirits. Even the slightest breeze will deposit gunk and small bugs onto the finish. Dust Collection, Safety and Plant Operation, Job Opportunities and Woodworking Services, Many different solvents can be used to thin poly, but the resulting slow-drying overspray can turn into a serious problem. Did you thin it or use any additive? Thin coats will help eliminate or reduce problems like runs in your finish. You can thin them, but the manufacturers usually state a limit (normally 10% or so) on the label. I know it can be sprayed because I’ve seen it sold in aerosol cans. Thinning Polyurethane for Spraying Many different solvents can be used to thin poly, but the resulting slow-drying overspray can turn into a serious problem. I have a HVLP gun and want to spray rather than brush polyurethane. That’s when I decided to buy a HomeRight Super Finish Max paint sprayer. The coverage of this product is 30-40 square feet per aerosol cane. Polyurethanes are a popular finish in wood working. Yes, it is possible. Has worked well for many projects. You will also potentially want to consider an HVLP for field work as they come in turbine styles that are portable which make them well suited for the field. Learn how to use polyurethane outdoors and how to thin it to be sprayed by an HVLP spray gun. Thin it heavily—50 percent or more—so you’re encouraged to apply very thin coats. How to Thin Water Based Polyurethane for Spraying Using Water-Based Poly as a Spray. Polyurethane can also be heat resistant making it a good coating for kitchen tables. To initiate a return you can contact us via phone and we can coordinate the return with you. Not all products qualify for free shipping. Apply only one thin coat. If you will be using a spray gun, you’ll typically hold the gun closer, while if you are using an air assist airless, you’ll hold the spray gun further from the product surface. We offer on site service in Ohio, West Virginia, and Pennsylvania3601 Library RdPittsburghPA15234. For starters, the paint you will use in the spray gun … My Polyurethane Change of Heart. Our primary carriers include UPS and USPS and for large items a variety of freight carriers. Spray it outside if you can. As mentioned above, there are several different types of products you can use to thin wood stain. Returned items must be in the original packaging. You may also need to add thinner if you’re trying to spray with a gravity or suction feed spray gun and are unable to get material to flow from the fluid nozzle. September 14, 2006, KnowledgeBase: Finishing: General Wood Finishing. 60 mesh filter in gun. Here is an overview of each: Mineral spirits (paint thinner): only to be used for thinning polyurethane and thining oil based stain and varnish. You'll need half as much finish, it'll dry before the bugs or dust can get to it, your recoat time will be much shorter, and you'll be able to sweep up any over spray. Thinning the epoxy resin using a solvent is very damaging to the strength characteristics of the epoxy. Naptha and mineral spirits are safer choices, but I often use lacquer thinner and even combinations of any of these products. Spraying overcomes this problem. Or if you can handle it, a CV would be even better. 10.4 Do you get Polyurethane Spray Paint? This will mean using smaller fluid nozzles (1-1.4mm) or air assist airless nozzle sizes and making a swifter pass over the product surface. [/quote] Hi Alan, This was sprayed with a Graco GX19, no thinning. For floor projects, use a square buff orbital or disk-type sander with 220 grit sandpaper or the equivalent grit pad or screen (specifically designed for sanding between coats). You can also consider a gun that will allow you to spray in both conventional or HVLP, like the Binks Trophy Gun which allows you to change from conventional to HVLP by changing the air cap. You may also need to … I use a conventional Spartan spray gun, no HVLP or LVLP yet. 2- Applying Spar Urethane As a subscriber you will receive the following perks: -  Advanced notice of deals and promotions, - Helpful content on equipment use, selection, and more. If you prefer to apply these finishes with a rag, thin them with about 50% mineral … Earlier this year I was getting ready to paint the outdoor coffee table and estimated it was going to take me SEVEN HOURS to paint the pieces with a brush! This paint is tricky. Thinning: Thin GF water based products with 10-15% extender or water at point of use only. Except as otherwise described below, if you are not satisfied for any reason products may be returned within 30 days of shipment for a full credit or exchange (if the product is undamaged). Generally, the dry time of oil based spray of too long but it get dried an hour or two. (Finishing Forum) Eventhough you are using a FFLP tip, you still need to have the PSI at 2000. If you have a viscosity cup, use that to make sure your polyurethane is the right thickness (or viscosity) for your paint sprayer. Spraying polyurethane is troublesome because of the slow drying and the sticky overspray that will coat everything in your shop. You can use mineral spirits, naptha, lacquer thinner... assuming that you have an oil base poly (not a waterborne). Spray on this coat using an aerosol polyurethane and let it cure overnight, photo below. If the poly is water-based and too thick, thin it by adding water (no more than 10 percent). Incidentally, the acetone may make the polyurethane appear cloudy in the cup, but it will dry clear. From contributor C: You will build your desired thickness … Due to polyurethane being a thicker coating, you may need to use thinner to reduce the material’s viscosity so that it can be sprayed well. Wipe-on varnishes are very much thinned and still work well. This oil based aerosol spray is recommended for interior wood projects like furniture, doors, cabinets, paneling and trim. This will typically require making faster passes across the product surface, as well as using smaller fluid nozzles (1.0 – 1.4 mm typically) or air assist airless tip sizes. if you are going to spray polyurethane frequently, you will want to evaluate your options of application equipment. A common question that woodworkers have is whether or not you can effectively spray polyurethane. Apply a very thin coat of polyurethane with a fine brush, foam pad, or cloth. From a single spray gun to fully automated systems. Decant what you need into a separate container and use immediately. The benefits of spraying over hand applying can include faster production and a finer finish appearance. NEVER SHAKE. But you need to be aware of a significant difference. Remove the cup and then unscrew the tip and submerge it in thinner. 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The strength characteristics of the options, will want an air assist Airless spray outfit email and send.