This is known as zebra stain. Zebra stains happen when iron or manganese darkens the browning and makes it turn black. Sun Exposure. If your wood product is left outside and exposed to the sun, over time it will darken (like a sun tan) and may make the wood appear dirty or damaged.
When you see the black mold cover wide areas of lumber, usually this happens because the wood got wet and stayed wet while it was being stored. If it's warm and humid, the growth of the mold and mildew can be rapid. Spotty outbreaks can sometimes be traced to food or liquids that nourish mildew or mold.
While blackwood and ebony are the most well-known, some species, like rosewood, walnut wood, and mahogany, can also have a blackened finish. Blackwood is a name given to several different species of trees, including those in the Dalbergia, Merremia, and Pterocarpus genera.
Sapstain: The most obvious form of discolorations, called sapstain or bluestain, is caused by the presence of pigmented fungi infecting wood. These fungi colonize mainly the sapwood and cause a bluish, greyish or black coloration to the wood.
After several years of growth, the wood cells become inactive and increase extractive content like resin, gum and tannin to become heartwood. Heartwood is usually darker in color than sapwood because of a higher level of extractives that give heartwood its color attributes and odor.
As a result of oxidation, wood subjected to heat treatments tends to lighten with time. Changes in colour also depend on the finish any particular wood was treated with. These phenomena are associated with the very nature of wood and have always been part of its beauty.
Dark wood stains have a high level of opacity, allowing minimal light to pass through the surface and resulting in a dark stain on the wood grain. Woods stained with a dark color just barely reveal the wood grain behind the stain.
What Are Those Ugly Black Marks? These back marks are called metallic discoloration, or iron stains, caused by elemental iron reacting with phenolic chemicals in the wood, forming black iron tannates. Iron stains require the presence of iron, water, and wood and will not occur if one of these elements is absent.
Patinas are a surface layer that develops on the surface of an item over a period of time. They tend to be a toned or darker layer that takes decades or centuries to naturally form on a material - unless the material is treated in such a way as to encourage a patina to form quickly.
Wood rot is mostly behind wood decomposition and crumbling. Decay fungi will darken your wood and cause it to shrink, leading to serious structural damage to the beams and joists.
Wood rot presents as decay, and mold presents as discoloration, usually black or white. Wood rot is a dangerous but avoidable condition often found in the wood of older houses.
There are thousands of molds that grow on wood, feeding on the structural polymers, sugars, and proteins in the wood. Generally, molds produce spores that are clearly visible as black, white, green, orange, or purple spots on the wood.
In its early stages, it will be gray or green in color, and sometimes white around its edges. As it matures, it will darken, eventually achieving its eponymous black hue. Within damp and dank rooms, black mold is especially likely to appear on wooden surfaces.
Wood Turns Black When Burning – A Summary
Due to the moisture still present inside the wood, underseasoned wood has a difficult time burning and turns black. Check the wood's conditions, where and how it's stored, the sort of wood, and your fire-building technique if you discover that it consistently doesn't ignite.
The main cause of staining through introduced causes, is Iron Staining. This happens when wood is sprayed with welding spatter or grinding metal. The iron then rusts when exposed to water leaving small black blotches over time.
There are many different options available on the market when it comes to wood stain, from oil-based and gel to water-based and varnish wood stains. There's no right or wrong answer when it comes to choosing a wood stain, it all depends on the desired finish look and the level of protection you require.
Black wood stain samples on pine
On pine, Varathane Classic Black had the most contrast and distinct grain lines. India Ink was definitely the blackest black, with just a hint of grain pattern. Minwax True Black is a happy medium between visible grain pattern and black color.
Wood stains, which can be oil- or water-based, contain dyes or pigments that soak into the wood to accent the grain. Clear wood finishes—varnishes, shellacs, lacquers, natural oils and water-based finishes—protect wood from moisture or sunlight.
However when wood is burned in an oven with the flow of air stopped, oxygen inside is soon used up and is not enough to oxidize the carbon in the wood. Thus the carbon is left to turn into charcoal. This is why when charcoal is burned, only carbon dioxide is released and there is neither smoke nor smell.
The heartwood por- tion of a tree is often darker than the sapwood and may appear to be discolored. Weathering will usually change the color of wood. In other cases, wood stains are due to the growth of microscopic organisms, the most common of which are harmless staining fungi.
Common types of wood decay:
Advanced stages of brown decay result in dry, powdery wood that is unable to support much weight, and crumbles easily. white rot: This type of decay appears whitish, stringy and mushy, and tends to be more common in hardwoods.
Black spots are formed when the wood is exposed to metal and moisture. Like a wet glass or leaky vase. This causes a chemical reaction from the tannic acid and water. The chemical reaction leaves black spots on your wood.