Over time, experienced painters and woodworkers learn to appreciate linseed oil and its many uses when painting or staining wood. Linseed oil is also known as flaxseed oil and has been a popular additive and conditioner for paints and stains for centuries. Part of using linseed oil effectively is understanding the properties of your wood type.
Here are some of the best uses for linseed oil when painting or staining wood.
1. Wood Conditioner
Painting or staining certain types of wood, such as pine or poplar, is not always a straightforward process. These materials can be extremely unpredictable at best. Sometimes when trying to add a light color to pine or poplar, the finish can often appear blotchy or uneven. Linseed oil can help prevent this.
The common belief regarding wood conditioners is that it's best to use on porous types of wood that really soak up the stain. While this is true, commercial wood conditioners can be expensive. You can easily create your own high-quality wood conditioner by mixing linseed oil and turpentine together and treating the wood with the mixture before painting or staining. The result will be a much better cohesive bond between the wood and paint or stain used to color the wood.
Do not misconstrue this to mean that linseed oil is a good finish. If anything, it is a coloring agent. Once applied, any excess should be wiped away, and you should allow at least 24 hours for the oil to settle and dry before attempting a true stain with a separate staining material.
2. Drying Agent for Oil-Based Paints and Stains
Adding a small amount of linseed oil to enamel or oil-based paint can actually speed up its drying time. This is useful if you live in a climate where humidity or other conditions would otherwise extend the drying period.
Linseed oil acts as a natural drying agent that helps bond enamel paint with the pores in wide-grain woods. Woods such as cedar or maple have a wide grain structure and will benefit the most from adding linseed oil to enamel paint.
The linseed oil can even be used throughout the painting process, cutting down the drying time and waiting period between individual coats.
3. Cover Paint and Stain Soaking Knots
Painting or staining wood with a large number of knots is difficult since the sap-filled knots often suck up too much paint and cause an uneven appearance in the final coat. However, linseed oil can help solve this problem.
Take a mixture of 1 part turpentine and 1 part linseed oil and brush a generous amount on the knots before painting or staining. Then wipe away any excess. Allow the mixture to sit on the wood overnight. The oil soaks into the knot in place of the paint and provides a less porous and more adhesive surface for the paint or stain to work with.
When you come out to paint the wood in the morning, you'll notice that paint spreads almost as evenly over the knots as it does the rest of the wood. You'll also notice that the paint is much more uniform and that the knots suck up little, if any, paint.
4. Light-Duty Polish
If you have delicate wooden furniture made of softer woods such as radiata pine or poplar, you can use linseed oil as a light-duty daily polish that will not plug the pores of the wood and prevent it from breathing.
Lightly spray a mixture of 1 part linseed oil and 1 part water on furniture and wipe it off with a dry towel. Do this two to three times a week to help keep your delicate furniture glossy and also help protect the wood.