Wood Grain Fillers
Fill Pores and Holes on Open-Grained Wood
Wood grain fillers help to smooth the surface of certain types of wood before stain, finish or paint is applied. Fillers are either water-based or oil-based and are used on the types of wood that are considered to have an “open grain.” In most cases, wood that is in the soft category is considered to be “closed grain” and does not require grain filler, but some hard woods need a layer of filler in order to produce a smooth final finish.
What Types of Wood Require Grain Filler?
The most common types of wood used to construct furniture that require grain filler are:
- Mahogany
- Hickory
- Elm
- Chestnut
- Ash
- Walnut
- Cherry
- Oak
In their raw state, these types of woods have large pores or “holes.” Some like the look of open-grained wood and do not choose to fill the grain. However, in order to achieve a smooth finish for furniture, the gain must be filled. If stain is applied to an open-grained piece of wood that has not had grain filler added to it, the stain will pool and soak into the wood’s pores unevenly, which will ultimately produce a darker finish in those specific spots. The result is splotchy-looking furniture that is also not smooth to the touch.
Water-Based vs. Oil Based Wood Grain Fillers
As with most oil-based substances, oil-based wood grain filler takes longer to dry than water-based filler. Both types contain similar bulking agents and the overall result is comparable. Colors and/or pigments can be added to both types of filler to create a shade that matches the wood on the furniture.
How to Apply Grain Filler
The application process is not difficult, but the wood must be prepared. In order to get an open-grained piece of wood furniture ready for filler it must be sanded. After the sanding process is complete, the wood grain filler should be stirred and thinned (if necessary). Most types of wood filler can be applied with a paint brush, a clean cotton cloth or a wood scraping tool. Make sure to add the filler to the wood in both vertical and horizontal directions (e.g. both with the grain AND against the grain) as well as in a circular motion. This will help to ensure that all of the wood’s pores are filled appropriately.
Make sure to wipe off extra wood filler before it dries. Once the piece is completely dry, a second layer of grain filler can be added if the surface of the wood is not completely smooth. After the furniture’s surface is level, it should be sanded again and then thoroughly wiped with a clean cloth to ensure that all left-over dust and debris is gone. After the sanding and cleaning process has been completed, it is time to apply the desired finish!
If Unsure, Practice First
Wood grain fillers are not overly complicated to use, but applying filler for the first time can be challenging for those who have never worked with this type of material in the past. It is recommended to practice on a scrap piece of wood before applying grain filler to the piece of furniture that will ultimately finished.
