You should sand after the first coat of water-based stain to flatten any wood grain the water raised, but it's unnecessary after that. You don't need to sand between coats of gel stain or oil-based stain.
However, keep in mind that if you sand too much, you are going to lose the color and protective nature of the layer of stain that you just put on. It is best to sand very lightly, using very fine sandpaper like 220 grit.
The way to get the smoothest and best-feeling finish is to “rub out” the last coat using sandpaper and abrasive compounds. Methods of doing this are written about often. It's a mechanical procedure that doesn't differ all that much from sanding the wood.
Note: Sanding between coats is not necessary, but it will provide a better finish. After a coat has dried, use 220 or 240 grit sandpaper or extra fine steel wool to lightly sand surface. This will ensure good adhesion of the succeeding coat.
Prep the wood finish for polyurethane
Before you even finish your wood project with wood stain or paint, for best results, make sure that it is sanded well and has a smooth surface. This is extremely important for not just the polyurethane top coat, but for the best wood stain or paint application too!
If you don't sand between layers of polyurethane, the surface may become streaky or discolored. This formula prevents chemical solvents from bonding to it. Once the first layer of paint is dry, you can apply a second coat to make sure everything remains. Each coat of oil-based polyurethane finishes is applied on top.
How long do you let stain sit before wiping it off? For a lighter stain, wait 5 to 15 minutes before wiping away. For a deeper shade, wait 30 minutes. However, don't allow the stain to dry on the surface before wiping.
Apply a second coat of stain after the first has dried fully. This will usually produce a darker coloring, but it adds a step to the process and slows production. Substitute a glaze or gel stain for the liquid stain. Glazes and gel stains usually contain a higher ratio of pigment.
We always recommend two coats of stain for any wood project, but you should only apply as much stain as the wood can absorb. Extremely dense hardwoods may only be able to absorb one coat of wood stain. The general rule of thumb is to apply only as much deck stain as the wood can absorb.
Sealing stained wood with Polycrylic
Polycrylic is a very popular sealant for wood projects. It is inexpensive and easy to apply. It provides strong coverage and is, in general, a great choice.
Remember: a stain provides color, but not protection. Once the stain has dried, apply a clear finish to protect both the stain and the wood—and to make the final results look even more beautiful.
If the color is then not even, or it's too light, you'll need to apply more stain. Switch to a slower drying stain, work on smaller sections at a time, or apply and wipe off the stain faster by using a cloth or spray gun to apply the stain and a large dry cotton cloth to remove the excess stain.
Sanding does help to lighten wood in many cases, but this only applies to surface soil or grime, and even then only if the discoloration has not penetrated very deeply. In addition, heavy sanding is not always practical. It may result in changing the contours of the piece, or in removing more wood than is advisable.
Sand to a coarser grit. To get a darker coloring with any stain when you are wiping off the excess, sand to a coarser grit. More of the colorant will lodge in the sanding scratches, producing a darker effect.
How Many Coats of Stain Should I Apply? Olympic solid color wood stains require the application of two thin coats for optimum durability. Applying two coats of solid wood stains will also hide wood grain and imperfections.
You should also consider the type of wood you are staining, amount of stain you're applying, and weather conditions, like humidity, temperature, and air circulation. On average, wood stain takes about 24 to 72 hours to fully dry and cure, though you can typically add a second coat after about four hours.
Stains lighten as they dry, then return to their damp color when a finish is applied.
Using a lint free rag is the best way to apply wood stain because it is great for controlling the amount of stain that is applied and for removing any excess stain. Also, the rag leaves a beautiful, even, and brush stroke free finish. It also can easily be thrown out once finished.
The most efficient method of applying stain is to wipe it on using a soaking-wet cloth.
No, the sticky stains will not dry after some time, which is why it is important to wipe off the excess wood stain. If you don't, your work will end up sticky because the stain did not dry properly. You will have to use mineral spirits, more stain, or sandpaper to fix the mess.
The Golden Rule of Sanding
The golden rule for choosing your sequence is to never skip more than 1 grit. For example, if you start with P80, and need to finish at P240, rather than using every grit from P80 – P220, you can do P80 – P120 – P180 – P240. This sequence cuts out P100, P150 and P220.
If you sand past 180 grit, the wood dust created by the sandpaper starts getting incredibly small. This wood dust can work its way into the wood pores, and clog them up. This prevents the wood from absorbing stain and finish properly.