Is Wood Grain Filler Necessary?

Are you concerned about how tedious and messy the process of applying a wood grain filler is? Well, if you’re wondering if it is optional, we’ll like to state that using grain filler for your finishes can deliver spectacular results. But can it be skipped? Is it essential? Here’s what we think on whether a grain filler is necessary.

Using a grain filler is more of preference than necessity. Most woodworkers don’t use them. Even though grain filling will make your projects aesthetically pleasing and more functional, you don’t necessarily have to use one unless you are targeting a distinct look or effect.

While applying multiple coats of finish to the surface of your boards and then sanding back may work for most wood species, open-grained woods like oak and walnut beg to differ. This is why grain fillers are used. But are they necessary? Let’s find out.

Is It Necessary to Use Grain Filler?

It is more of an aesthetic decision and not a requirement. It all hinges on the results you desire. For example, the glossy finish that comes with grain fillers may seem unappealing to some artisans who like to keep the look and feel all-natural. So, they don’t fill the pores.

On the other hand, the natural look is less than elegant to some woodworkers. To this group, a mirror-flat appearance is what they want, so they fill the wood’s pores.

Like we said before, the final look and feel you want to achieve determines which way you’d go.

So, When Is It Necessary to Use Grain Filler?

Now you’re probably thinking, “at what point does pore filling become necessary?”. First, you’d have to consider whether you want a faultlessly flat surface.

There are some species of wood that no matter how much or well you sand the surface back, you won’t get that smooth finish you desire unless you fill before finishing.

Let’s say you are making a guitar from ash. A grain filler turns a crude-looking guitar body into an exceptional piece. It gives you a smooth glass finish that hours of sanding won’t deliver. But, of course, you want to have the surface as smooth as possible.

If you’re applying a finish like lacquer on open-grained woods, you need to use a grain filler first. Or else the lacquer would sink into the pores of the grain, and you won’t get that smooth finish you want.

Another example is making furniture from oak, mahogany, or other species with large open pores. Again, since you’d likely be aiming for elegance. In these cases, you need to use a grain filler.

Effects of Wood Grain Filler on Wood

Here are some of the effects grain fillers have on wood

It provides an even smooth surface

We are all aware that open pores are blemishes that reduce the visual appeal of your projects. Besides, it is very easy for dust and debris to collect in the open pores of a wooden surface like your tabletop or cabinet doors that may prove difficult to clean. A grain filler protects against that.

It delivers a smooth reflective finish

Imagine applying high gloss on an unfilled guitar body. It looks all wrong, right? Yes, it is improbable that you’d want a rough-looking project unless rustic is what you want.

Increased Visibility of the Wood Grain’s Nuances

Another plus when you opt for wood grain fillers is that applying one accentuates the grain’s subtle nuances that may get lost in the coloring process. Here’s how to achieve this;

Dye your grain filler to a darker shade of your desired color and rub it into the wood, then spray the guitar with the primary color. Be careful with the dark dye to avoid over pronouncing the effect as it may end up making it look unappealing.


Finally, it’s also crucial you know that grain filling prepares the wood surface for subsequent application steps, especially when using lacquer or varnish on species like ash, oak, and mahogany.

Should I Use Grain Filler on Oak?

If you don’t want grainy or rustic-looking projects, then you should.

The process may seem time-consuming and tedious, but it is worth the effort. Rolling a primer or applying multiple coats of finish would not take care of the large pores that contribute to the intense grain pattern oak is known to have.

We know it is nearly impossible to do away with all the hard grain from oak. Still, two to three coats of a grain filler should suffice to reduce it to a much smoother finish that can be sprayed or painted. Multiple applications of the filler would leave no trace of the oak pattern behind.

Another way to hide the grain pattern is to apply two coats of BIN primer after a single application of grain filler. Sand back in-between surface applications. This works pretty well in filling the grain but is not as effective as multiple coats of grain filler.

Do I need to Grain Fill Pine?

Pine is a softwood that doesn’t need a pore filler, irrespective of the type of finish you plan to use. This is because it is medium-textured and close-grained. All it needs is a good finishing job. Here are finishing processes that will get you the result you desire

Sanding: Sand the wood grain carefully to remove any scratches from the wood surface. Make sure to sand the surface uniformly and thoroughly.

Tacking: Get rid of all dust residue by wiping the surface with a tack cloth.

Priming: Spread on a single coat of primer in even strokes following the direction of the grain. Allow it to dry, sand back, and wipe using a tack cloth.

Finishing: Apply a sealer coat first before finishing, especially if you would be staining. This helps because pine has a variable absorption rate that may look blotchy after staining. Or you can stick to clear finishes like varnish and polyurethane, which pine accepts well.

Grain fillers are necessary when working on open-grained woods like oak, ash, and mahogany. It helps reduce the grain pattern by filling the pores and leaving an even smooth surface sprayed or painted. It is unnecessary for close-grained woods like maple, beech, and pine.

If you don’t know the difference between open grain wood and closed grain wood, don’t worry; we got you. Check out our article on Open Grain Wood vs Closed Grain Wood to know more about it.

But you can fill it if you want to. Also, if there are large cracks and holes in the wood, you should consider applying a wood filler.

Final Thoughts

Grain filling is a good step in the finishing process of a wood project. It helps enhance the appearance of your results. It gives a beautiful smooth surface and prepares the boards for subsequent steps. But it is not a compulsory one. You can skip or use it if you want to. It all depends on your preference.

Martin Swizz

Hi! This is Martin, I like to research, experiment, and learn new things related to wood carving and other kinds of woodworking.

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