Yellow pine is one of the hardest varieties of pine wood available. It is often used for hardwood flooring or paneling, but it can also be used for pyrography, or artistic wood burning. Aim for broad textures, patterns or gradients when using a propane torch for pyrography, as it has less control than a wood burning pen. Yellow pine is often sappy, so overheating the wood can make the sap bubble to the surface, creating fissures in the wood.
Propane torches apply broader burn strokes and more heat to wood than traditional wood-burning pens. To prevent overheating, keep your yellow pine object moving while you work by placing it on a turning table. Keep your torch flame moving as well, even if the object is already turning, and take frequent breaks. Always keep a fire extinguisher and spray bottle nearby, and never work indoors with pyrography. A concrete patio or driveway a good distance from any building is recommended. Yellow pine is especially reactive to heat and sap can bubble up and split your wood if you're careless. Do not attempt detailed line work with a propane torch, as you will not only fail, but likely ignite your work.
This technique will create a rich, obsidian coloring to your work. Use broad, even strokes from your propane torch over the entire surface of your yellow pine object. As flames tend to rise, begin with the bottom of your piece, and always keep it turning. Be patient with a blackout burn, as it may require many layers to complete. Allow your work to rest for 30 to 45 minutes for every 10 to 15 minutes of burn. If you see sap bubbling or notice cracks, reduce your work time. Sand and varnish your work once the blackout burn is complete.
Caramelizing will apply a warm, brown glow to your work, but requires far more finesse than a blackout burn. Professional wood turner and pyrographer, Steven D. Russell, recommends slow, arcing strokes -- somewhat like an airbrush -- to achieve the caramelized effect. Yellow pine is already rich in color, so you should only apply light burns to the surface. Begin at a good distance and work closer until you can see minute coloration. Work from this distance and keep the piece turning.
Follow the wood grain of your object to achieve the zebrano effect. As your standard propane torch will use broad strokes and a great deal of heat, you will have to move the flame quickly -- and closely -- over the surface to avoid overheating the work. You will also have to turn your piece by hand, so you need to wear protective gloves. Practice on a piece of scrap yellow pine before you attempt the zebrano effect on your object. You will also notice char flaring around your lines. This is expected with a broad-flamed tool, so use it to your advantage and blend lines around knots or close grains.