Hardwood Vs Softwood Essay Example

of ignition in electrical and dust extraction equipment.

If there is a fire, use water jets to extinguish the flames. Ingesting softwood dust may cause discomfort, but it generally causes fewer issues than three specific hardwoods. To ease symptoms, drink water and seek medical advice if needed. Contact with softwood dust can irritate the eyes, resulting in redness and watering. It is recommended to wear protective glasses during work. Inhalation of softwood dust may occasionally lead to irritation in the nose, lungs, and throat.

When exposed to wood dust, it is advised to always wear a dust mask. Softwood should be stored in a well-ventilated area and kept away from heat, flame, and sparks to avoid any potential danger of explosion when mixed with air. Timber has two main structures which can be observed under a microscope. Hardwoods are typically characterized by their large vessels or pores. However, it is important to note that the term "hardwood" does not necessarily indicate the hardness of the wood itself; for instance, balsa wood falls into the hardwood category despite being one of the softest timbers.

Hardwood is made up of interwoven tubelike vessels, which makes it stronger than softwoods. Examples of popular hardwoods include eucalypts, oaks, ashes, red cedars, and hickory. In Australia, Jarrah, Spotted Gum, and Tasmanian Oak are easily accessible. For outdoor furniture manufacturing in particular, Jarrah is mainly used. You can find Spotted Gum and Tasmanian Oak at local Yeppoon Hardwares. On the other hand, softwoods or non-pored woods have a simpler cell structure compared to hardwoods. Under a microscope, softwoods appear like brickwork due to their composition consisting mostly of elongated narrow cells called tracheids.

Softwoods, such

as western red cedar, cypress, and radiata pine, offer mechanical support but have lower strength-to-weight ratios compared to hardwoods. These types of softwoods are commonly available at local hardware stores. However, the timber industry has increasingly used natural hardwoods, which possess characteristics like high density and abundant extractives (such as waxes, oils, and resins), making them challenging to glue. Therefore, it is crucial to use different adhesives for different applications.

Adhesive should be chosen based on components, species, wood grain direction, and service conditions. It is recommended to glue immediately after machining. Research indicates that epoxy resin is not suitable for hardwood, though this may vary by species. Gluing or finishing spotted gum can be challenging due to its extractives, requiring lengthy seasoning. As a result, many outdoor hardwood furniture pieces are assembled using screws instead of joints and glue.

Softwoods are well-suited for modern gluing techniques because of their generally porous nature and minimal extractives. Their low density allows glue to penetrate the open cellular structure of the timber. It is important to research and select adhesives that are suitable for specific applications based on weather exposure and strength requirements. Commonly used adhesives for softwood include polyvinyl acetate, high strength wood glue, and epoxy resin. The sustainability of using hardwoods raises significant environmental concerns.

Can trees be continuously harvested? If not, eventually it will have to stop, and the consequences of depleting resources and damaging the environment are similar to those faced by any population that outgrows and ruins its habitat. The majority of hardwood timbers used in construction come from old growth native forests. On average, lumber is made from a tree that is cut down

at 25-40 years old. Currently, there is a depletion of hardwood timber because it is being used faster than it can be replaced. In terms of environmental impact, converting timber has two main concerns. Firstly, carbon dioxide in the atmosphere leads to a gradual increase in overall temperature, creating a warming effect on Earth.

The diagram below shows that for every ton of timber sawn, 30 kilograms of carbon are released into the atmosphere. While this amount is small compared to steel or aluminum production, it is important to ensure that trees are grown at a faster rate than they are cut down in the long term. One key difference between softwood and hardwood is that softwood mainly comes from sustainable plantations. Softwood trees usually reach maturity within 10-30 years, much faster than hardwood found in old-growth forests. Both types of wood release carbon emissions during milling, contributing to the greenhouse effect. However, carbon is still stored in timber from softwood plantations, whereas hardwood is often milled without replacement, resulting in released carbon that isn't absorbed by new tree growth like in softwood plantations.

The report examines the durability of various hardwoods compared to softwoods. Hardwoods in this study demonstrate greater strength relative to their weight, making them more durable. Notably, both spotted gum and Jarrah possess exceptional resilience and weather resistance, even without any added finishing. On the other hand, Tasmanian Oak is softer and more susceptible to rot and fungal damage.

All of these timbers will crack and warp if left unfinished as the moisture moving in and out of the wood eventually degrades the cellular walls. Softwood in exposed situations offer very limited durability. Most

species are very prone to decay, warping, splitting and this combined with their softness makes them not really suited to any outdoor application.
This has been overcome in recent years by treating pine with Chromium Arsenate a timber preservative which is placed in the timber under high pressure. Treated pine is guaranteed to last in the weather approximately 40 years. This treatment however does leave the timber with a distinctive green colouring restricting the design aesthetic options.

This report has investigated various aspects including safety, structure types, availability, adhesive properties, environmental issues, and durability of timber used in outdoor furniture manufacturing. The goal of this report is to provide clear information about the best alternative when choosing timber for this purpose. The comparative table below presents the strengths and weaknesses of the two types of timber:

The comparison table emphasizes that hardwood is significantly better for manufacturing outdoor furniture. Although it may not be as environmentally friendly as other materials, hardwood offers the necessary durability and exceptional strength required for this purpose. In terms of safety, the primary concern is dust exposure, which can be easily addressed by using appropriate protective equipment such as a dust mask or respirator.

Bibliography

1. http://www.hartingdale.com.au/adh/index.html
2. http://www.ifa.unimelb.edu.au/issues/wa/pinehw.htm
3. http://www.nafi.com.au/links.html
4. http://www.brs.gov.au/nfi/forestinfo/callitris.html
5. And personal knowledge.