All types of wood require at least two coats of oil-based polyurethane. The first coat works as a primer and sealer; the second serves as a finish coat. With water-based polyurethane, a third coat is recommended, because the finish wears away fairly quickly. Sand between coats if dust or lint gets into the wet finish.
Most kitchen cabinets require three to four coats of polyurethane to achieve a durable, long lasting finish. Sand, wipe and apply polyurethane until the desired coating is achieved.
For best results, apply at least two coats of polyurethane. When working on floors, tables, chairs, and furniture that will be used often, apply at least three coats. If you are using water-based polyurethane, you can apply up to four or five coats on floors and sheds.
You do not need to apply a polyurethane finish to painted kitchen cabinets if you've used a durable paint. If you chose a less durable paint, a clear polyurethane topcoat can help prolong its life by protecting it from premature wear. Unfortunately, not all polyurethane finishes are suited for all types of paint.
You can even use one coat and be fine. However, remember not to apply more than 4 coats of oil-based polyurethane or 5 coats of water-based polyurethane. Unlike when you apply less, you can't get away with applying too many coats regardless of the surface that you painted.
If you use water-based polyurethane, you only have to wait between 2 to 4 hours before applying the next coat. However, when using oil-based polyurethane, you might wait for 10 to 24 hours. You can apply the next coat in as little as 4 hours if you are using fast-drying, oil-based polyurethane.
For some types of poly, nothing happens if you don't sand between coats of polyurethane. However, most polyurethane will not adhere properly if you skip sanding dust nibs and brush marks on the finish. The polyurethane finish will eventually peel off or become deformed.
All types of wood require at least two coats of oil-based polyurethane. The first coat works as a primer and sealer; the second serves as a finish coat. With water-based polyurethane, a third coat is recommended, because the finish wears away fairly quickly.
Polyurethane dries in 24-48 hours and takes about 30 days to fully cure.
Do not apply too much polyurethane in one coat, as this can result in the wood grain rising to the surface. You will not need to sand the surface between coats of water-based polyurethane, but it is always best to do it anyway. You will need at least three coats for a surface that is lightly used.
Sand the dried and cured first coat of polyurethane no sooner than 24 hours after applying it. Use a very fine-grit abrasive, sanding with the grain of the wood. Remove the sanding dust first with a static duster, followed by a tack cloth.
Durability of Water Based vs Oil Based Polyurethane
Oil based used to be unquestionably more durable. Today though, water based polyurethane has evolved with better formulations that are equally durable as oil based polyurethane.
So, to recap the answer to this question: You should always use a clear coat on painted cabinets unless you feel like doing a lot of repainting.
As for applying any sealer or topcoat, the general pro recommendation for cabinet painting is to use high quality stain blocking primer and 2-3 thin and even coats of super high quality paint with ample drying time between coats (Benjamin Moore's Advance paint is meant for cabinets without any top coat, since sealers ...
On average, semi-gloss oil-based paint is the most durable finish for kitchen cabinets. Because of its sheen, semi-gloss paint can reflect light and remain durable for a long time.
Allow each coat to dry fully. To give the subsequent poly layers something to bond to, sand lightly between coats with 320-grit sandpaper wrapped around a hard block.
I'd wait, If you coat too soon after the recoat window closes you can have something called a "Recoat Lift" It'll cause the layer underneath to wrinkle and lift off. If at all possible, wait the 72 hours instead of having it potentially get funky and have to be all sanded off and start over.
Let it soak between coats.
When you're done with the brush, rinse it a couple of times in used mineral spirits, then pure mineral spirits, removing the bulk of the solvent on newspaper each time.
Open windows and doors. Use a fan to direct fresh air over the area. It can take up to seven days for the urethane to be 90 percent cured and 30 days to be cured completely. However, you should need the fan only for the first day, with periodic use after to remove buildup of fumes.
Yes, you can apply polyurethane with a rag. Applying polyurethane with a rag is a good way to avoid paint bubbles, brush marks, and also helps you to paint hard-to-reach surfaces. There are many different ways to apply polyurethane, but the most common methods include spraying it or wiping it on with a rag.