I now tend more to oil finishes for our woodworking projects; there is something to be said for a high-gloss finish. It adds a wonderful air of elegance to wood and adds depth and quality to its appearance.
QUICK ANSWER:
To get a high gloss finish on wood, start with thorough sanding, use grain filler for open-grain woods, apply multiple coats of shellac or varnish, and finish with careful buffing using high-grit sandpaper and a polishing compound.
One of the reasons I like oil finishes is that they enable the full warmth of the wood grain to shine through as the star of the project. A clear and glossy finish, though, does that same thing, and I can endorse that for projects, too.
For that to happen, it’s necessary that the finish (I’ll get to a few of them later in this article) be even in its coating of the wood, and the wood must be even, too.
That will ensure great light reflection; the more light reflected, the shinier the surface.
Preparing The Wood Is Important
In order to achieve the highest reflection of light, it is necessary to have a smooth finish. In order to get a smooth finish, it is necessary to create a smooth surface for that finish to sit on.
When light hits the surface of the finish, it either comes back to us at an angle complimenting the finish, or it is separated and bounced at many different angles. The former presents that gloss wanted, while the latter diminishes the gloss.
The diffusing of the reflection will be caused by defects and imperfections either in the wood or the finish. This makes prep work on the wood essential for the gloss. Surface imperfections will deflect the light, and that will mean the surface is not smooth.
When prepping the wood, you eventually want to work your way up in grit number until you reach a minimum of 400 grit sandpaper. Surface preparation is an important part of the project, and a flat surface without defects or imperfections will get you halfway to your high-gloss finish.
Wet sanding can also help; if you are unfamiliar with wet sanding, it is exactly what it sounds like. Using water as a liquid lubricant helps wash away grit particles. It also helps you avoid scratches on the wood surface and will lead to a smooth and even finish after your dry sanding with 400-grit sandpaper.
You also want to be sure to use a damp cloth after dry sanding to remove any lingering sanding dust particles from the surface. If left on the wood, they are another imperfection that will inhibit a complimentary angle of light reflection, dulling the finish you were hoping to achieve.
The Wood You Choose Will Impact Smoothness
Of course, it matters to start your work with as flat a surface as possible and then sand the wood to a smooth surface. There are some woods, though, that has an open grain with large pores, woods like walnut and mahogany. Sanding may not be enough to get the smoothest surface you’re looking for; that is where some filler might be necessary.
Products like Aqua Coat Water-Based Wood Grain Filler or Goodfilla Wood Filler will fill those pores for you. These wood filler products are easily sanded once applied and allowed to dry fully. If the pores are not filled, they will constitute enough of a surface imperfection that will diffuse light reflection and diminish the glossy finish no matter how carefully you apply it.
Water-based grain fillers tend to be thick. But, because they are water-based, they are easily thinned with – you guessed that – water. Mix it well when adding the water, and look for a creamy consistency. Apply it moderately, and be sure to wipe away most of the excess filler so that just the pores are filled.
A damp cloth can help, as can one of your credit cards. Allow the filler to dry fully, and then lightly sand away with a high-grit sandpaper down to a smooth surface. Again, make sure all of the sanding dust is removed using a shop vacuum or a soft cloth.
These grain fillers are readily available at local hardware stores, DIY stores, and online retailers. They are not expensive and are good to have around in your woodworking shop as a part of your finished product inventory.
Applying High Gloss Finishes
Approach the finishing of your wood only with a high-gloss finish. Don’t build up a satin or matte finish expecting the final coat of glossy wood finish to do the trick.
Choose a finish like a shellac or varnish. Each of these finishes builds upon the previous coat, melting into each other, if you will, meaning that after all of the coats of finish applied will form a single, thick layer. The point we’re making is this – no defects or imperfections in the finish will result.
You could sand between each coat of finish applied, but it’s probably not necessary. However, you will be wise to do so before the application of the final planned coat of varnish or shellac. Actually, we don’t mean to limit the choice of finish to just these two, but their nature to form a single layer after multiple coats is appealing.
However, lacquer could also be a good choice for a high-gloss finish. Plan on 4-5 lacquer coats if brushed, 6 – 8 coats if spayed, and save the sanding again before the final planned coat.
Allow The Finish To Dry Fully
Ensure you allow each finish coat to dry fully before applying subsequent coats. Again, it’s not necessary to sand between each coat.
After the final coat has fully dried, you will want to buff to add even more luster to the finish. Cotton buffing cloths will serve well, but a power buffer will also do well in adding a further gloss to an already glossy finish.
Before buffing, a very light sanding with ever-increasing grit number paper, from 600-grit up even to 1200-grit, will adequately prepare the surface for buffing. That high a grit paper will not lead to any sanding scratches, and the surface will be ready to take a buffing compound.
A rubbing compound may not be necessary if the sanding has prepared the surface well, and you can go directly to a polishing compound. You can apply the compound with a tack cloth in a swirling motion and then bring on the power buffer. If you polish your own car, you know about polishing compound and power buffers and the mirror-like finish you can create.
It is true that even the softest of cotton buffing cloths on your power buffer can leave a very fine scratch. But they will not be visible to the human eye, and you don’t need to worry about this.
All these steps will result in a shiny finish and a highly reflective finish, even a mirror-like finish.
Video Demo for a High-Gloss Finish on Wood
I’ve returned to one of the channels we follow on woodworking to find a presentation of rubbing out a high gloss finish on wood. He discusses filling pores, prepping the wood surface well, and buffing, just as we have in this article.
Sometimes it helps to hear this or see this, in addition to reading this, so here you go.
Whether it’s a shellac or varnish, or a lacquer finish, you’ve chosen for your preferred finish on your project, the approach is the same.
Prep the wood very well, get that smooth surface, use a filler to smooth the grain pores, apply the finish coats, sand before the last one, let each coat dry fully, buff out the surface, and the result will be that glossy finish you want.