Requires less sanding: You don't need to sand between coats with lacquer (like you do with polyurethane) — and you don't even need to sand your project that high before finishing. I usually only go up to 150 grit, and the end result still feels ultra smooth.
That said, two coats of lacquer is usually enough to provide a great finish that will last for years. It doesn't tend to yellow over time like other products do either so will keep your surfaces looking fantastic for longer.
The quick way is to lightly wet sand the surface with 600 grit or 0000 steel wool and then put a thin final coat of lacquer on top. That final coat will restore the gloss while retaining most of the smoothness from the sanding. The slow way is to wet sand, starting at 400-600 and working your way up to 1500 or higher.
The end-goal for painting projects is to produce a very smooth finish: One way to achieve this is to lightly sand between each coat of primer and paint you apply using fine-grit sandpaper. Sanding between each coat of primer and paint is one way to achieve the best finish for any painting project.
Requires less sanding: You don't need to sand between coats with lacquer (like you do with polyurethane) — and you don't even need to sand your project that high before finishing. I usually only go up to 150 grit, and the end result still feels ultra smooth.
Make sure to sand the polyurethane between coats. Sanding removes drips, bubbles and other uneven spots in each coat. Dry the first coat for a full 24 hours. If the coat feels tacky or sticky after that, let dry until it feels completely dry.
In short, that rough texture that you feel is basically a mix of micro-level dirt that has stuck to your clear coat that won't come off with a simple wash.
When you overlap the spray, you even out the coating of the lacquer. Never try to even out the lacquer film by brushing it. Apply a thin coat first, allow it to dry, smooth it out and clean it, then apply another thin layer. Repeat until you are satisfied with the finished look.
After the lacquer cures for a few weeks it can be sanded perfectly level and buffed to a high gloss. During those weeks, almost all of the solvents evaporate and the remaining solids get dry and hard.
As for time between coats, it all depends on the product and the instructions on the can but generally speaking, most products want 5-15 minutes between each coat of that product on top of itself, depending on temperature, and about 30-60 minutes before going onto the next product.
Thinner coats of all finishes dry faster than thicker coats. The difference is great enough that you can build the same thickness with several thin coats in less time than you can get that thickness with a thick coat.
How to Sand Lacquer. If you're hand sanding lacquer, start by wetting the surface lightly and using 320- to 400-grit sandpaper to smooth the surface until you see your desired sheen and finish.
The idea here is to brush on a thin coat of lacquer thinner, causing the old lacquer to reactivate and be spread, just as it did when it was first applied long ago. Any scratches or blemishes should disappear before your eyes.
Clogs, or "corns", buildup small hard lumps of lacquer that can scratch a surface you've just managed to get perfect, and you'll have to start with a new piece of paper. Wet-sanding lubricates the surface, washing out any grit-clogging particles and reduces the heat of sanding.
But you must know how many coats of lacquer on wood. Usually, three to four coats are enough, but you need to consider several aspects before deciding on the number of coats.
When applying several coats of finish to a project it becomes necessary to sand between coats to not only remove any trash that has settled into the finish but also to promote good adhesion between the layers of finish. Here are some tips: Never sand any finish with less than 320 sandpaper.
Polyurethane is more robust and durable, making it ideal for high-traffic areas and outdoor use.
Lacquer is toxic, and also requires solvent (lacquer thinner) to clean equipment afterwards. I sprayed lacquer for a short while, but found the trade off for clean up and disposal was not worth the switch from water based poly. That being said, it's easy to spray, cost effective, and gives excellent results.
The material you're painting will also determine if sanding between coats is necessary. As a general rule, if the surface you just painted doesn't feel or look smooth, sand it!
Coat the entirety of your workpiece, but don't brush excessively or you'll create areas with too little polyurethane. 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.
Waterborne polyurethanes usually require a minimum of 3-4 coats to be effective. Although there is some evidence that too many coats can result in a plastic-like finish, waterborne polyesters are thinner than other types and therefore require several more coats to provide the same protection for hardwood floors.