To limit wood damage, preserve furniture AND keep it looking natural you'll want to seal raw wood with Liming or Cerusing wax. Any other wax or poly (from my experience) will darken the wood, enhance orange tones and change the color.
While leaving natural wood projects bare is an option for some, in our house, dirty fingers and kids make top coats for furniture very necessary. Natural wood is susceptible to damages such as water rings, scuff marks, household chemicals, etc.
Use a rag to slowly apply 2-3 coats of the oil, making sure to wipe up excess oil as you go and sand in between coats. To take extra preservation steps, use a "wood preservative," limit the wood's exposure to water and sun, regularly wipe off dirt, stain and paint periodically, and keep the nearby area ventilated.
While you might expect it to do nothing or just leave a small stain, rubbing alcohol acts as a solvent when it comes into contact with wood and wood finishes. To understand how big of a problem this is, you need to know what a solvent does. Solvents are designed to liquify wood finishes, including varnishes and stains.
-If it is a piece that will get a fair amount of use – like a tabletop; apply a coat or two of soft beeswax based paste wax to protect it. This will condition the wood, keeping it looking very natural with a matte finish while enhancing and protecting the wood grain.
To treat untreated wood for outdoor use, you need to apply the treatment. This treatment contains chemicals that can make the wood shrug off insects and harsh weather. The best option you have to treat wood for outdoor use is pine tar. It's a popular option as it can provide a stain-like finish.
Use an outdoor-rated finish like polyurethane, epoxy, lacquer, or varnish. Make a natural oil finish with one part tung or linseed oil, one part mineral spirits, and one part polyurethane. Use a stain sealant combo that gives your wood some color and a durable finish all in one.
Shellac. In my opinion, shellac is the best natural wood finish for one main reason: it's the most protective natural finish on the market. Unlike other options, shellac forms a barrier on top of the wood, stopping water, dirt, and other things (*cough*crayon*cough) from reaching the pores of the wood.
Paint Or Seal Unfinished Furniture
Bare wood, when left unfinished, keeps your furniture with a natural wood look but the risk is exposing it to harsh elements, even if it's indoors, such as light, dust, moisture and water damage, making it more susceptible to stains, warping and cracking.
Tung oil is often recommended as a sealing oil for furniture because it protects the wood from moisture and stains.
Varnish is great option to treat untreated wood for outdoor use because it's relatively cheap and provides superior protection for your wood. It can also last longer than some other sealants, which is something we all want.
Wood can Start to Rot in 1-6 months If:
Wood is untreated. The wooded area is sitting in water. Water and/or air space is hot & humid.
You simply soak the lumber in the borate solution. Most people just build a trough using 6-mil plastic sheeting. The different borate chemicals come with instructions telling you how to mix the powder with water and how long to soak the lumber.
It usually consists of linseed oil, Tung oil, mineral spirits, synthetic resins, and/or varnish. It is usually food-safe (check the label) so it is a popular option for kitchen cabinets, cutting boards, and wood counter-tops.
Softwoods such as pine, redwood, fir, cedar and cypress are not ideal for cooking because they contain terpenes and sap. This gives the meat a bad flavor. Each wood produces a different flavor. The climate and soil in which it grows greatly impacts the flavor.
Stay Away From Softwoods
Softwoods are trees with needles or scale-like leaves that typically stay on the tree year-round.  Some examples include pine, fir, cypress, spruce, and cedar. You shouldn't cook food over softwoods for two main reasons. First, they burn quickly as they're less dense (contain more air).
Mineral oil, also known as liquid paraffin and butcher's block finish, is easy to apply. It has lower water resistance and requires reapplication more frequently. Mineral oil is one of the most common food safe finishes.
A kitchen staple, white vinegar is a natural way to clean a number of items. It is also safe enough to use on unfinished wood, though never apply it straight. It can be used to remove general grime, but also fingerprints and is a natural way to kill bacteria if you do not want to use dish soap.
Finished surfaces: Since the ethanol in it is a solvent, rubbing alcohol can liquify varnishes or finishes, doing major damage to your furniture or other surfaces in your home. Avoid rubbing alcohol on painted, shellacked, lacquered, or varnished surfaces, including treated wood.