Posts Tagged ‘structure’
What you Need to Consider in your Search for a Chiminea
What you Need to Consider in your Search for a Chiminea
The tribesmen back in Mexico, during the 17th century, introduced to the world of fire pits and fire places a new structure that served the same purpose. Its characteristic long neck attached to the rounded bottom resembles a chimney and serves a similar purpose there as well. It is an outdoor fireplace that can also be used to grill skewers and cook meat. When not in use they are an ornamental addition to the garden or patio. These are normally made up of clay, aluminum and cast iron. You must know some facts about chimineas before deciding the kind of chiminea that would be apt for your backyard or other outdoor living space.
When it comes to choosing clay chimineas it sure does sound like a pretty good idea because that is how traditional chimineas used to be. And when used for cooking it produces a lot of heat and its temperature raises high in a short span of time. The food cooked in these clay chimineas may have a different flavoring as well that comes in with the mixture of charcoal and clay particles. These clay chimineas can be either air-dried or kiln-dried. The air-dried version is generally the untreated version and may need some painting to be done to completely coat and seal it. The kiln-dried versions do not require any extra touch ups. The clay chimineas are weakly bound at the neck of the structure i.e. the junction between the end of the round bottom and the start of the neck-like structure so it is not advisable to carry the chimney at the neck.
Metal chimineas as compared to clay chimineas are way better with a lot of advantages over their clay counterparts. Metal chimineas are considerably stronger and more durable. They cannot be easily damaged or broken like the clay chimineas. They do not allow seepage of water into their bodies unlike clay chimineas and thus do not have the limitation of not being able to use in moist surroundings. They also conduct heat very efficiently. However, all the burning activity might give rise to rust on the metal body which needs to be maintained every now and then. Even then the rusty body gives it an antique look and it only enhances its presence as an attractive show piece.
Another thing to be considered is the size of the opening for the fuel inlet. It should be large enough to easily accommodate wood pieces of variable sizes. So it would be productive if you choose a chiminea with a larger bottom. You can also purchase a spark arrester which is a mesh like structure that can be used to cover the opening at the top of the chiminea or at the opening at the bottom. This would prevent sparks from escaping outside and damaging the surrounding. In all, it is a great addition to your backyard with all its uses and its heating properties. Chimineas are a great addition to any outdoor living space.
Amber Liddell is resource for Net Health Shops, your online stores for indoor and outdoor living. At PremiereFirePits.com you will find a full selection of fire pits, chimineas and patio heaters.
Article from articlesbase.com
Posted in Cast Aluminum Chiminea | 
Tags: Clay, clay chimineas, metal chimineas, Neck, structure, touch ups | 
No Comments »
Tips on Building Your Own Fire Pit
If you are you surprised on how to build a fire pit and to find out the steps involved in making a backyard fire pit that you will be proud of go on reading this article. As a homeowner, making an open-air space that your family can make use of all through the year is an excellent initiative. Unpleasantly cold summer evenings or fall nights don’t have to trail you indoors as soon as you’ve got a warm fire pit to get together. Here’s what you want to be familiar with to set up a simple fire pit bowl.
You will have to collect these materials to put together your fire pit, a few 3×8 lumber, galvanized screws and fasteners to fasten, sand, small gravel or rocks, cement, a steel fire bowl, miter saw, drill for making holes, screwdriver.
Make use of the 3×8 lumber to construct a structure for your fire pit measuring 60×60 inches square. Complete your structure by finishing with four more pieces of lumber and using it to build an attractive border all along the top of your structure. You will need to take care your border has mitered trimmings with the intention that the corners have a smart looks. As soon as the border is finished, make use of the screws to fasten it to your structure. You can coat your frame with color, if you want. Take care that it is fully dried up earlier than you move to the next step.
Lay the structure in the area where you would like your fire pit to be positioned. Take care that the structure is level. Load the structure with about two-thirds of sand filled in it. Level the surface with a smooth leveling tool. At this instant you will put the fire bowl in top of the sand. Be certain to put a little additional sand up alongside the bowl to hold it in position. Now put in the small gravel or rocks until the sand is fully covered.
At this time you can begin to enjoy your backyard fire pit. However, it’s essential to be safe as soon as you are managing an open fire. You will need to take care that you haven’t positioned your backyard fire pit very near to your home. You should set the fire pit no less than 12 feet away from your home. This as well applies to your garage, shed, fence, or other things on your home. As it comes to your backyard furniture, keep some tables and chairs as a minimum four feet further than the fire pit.
You may have to buy a screen to contain stray sparks from flying out. At all times be certain that the fire is fully extinguished earlier than you leave it, as well. Take care of the weather conditions; if it’s very breezy outside, avoid lighting the fire and leave it for other occasion. Now that you are familiar with how to build a fire pit, you can simply decide on a personalized design, which will make a balmy open-air atmosphere in your own back garden or patio.
Posted in Sculpture |
Tags: Building, Fire, galvanized screws, how to build a fire pit, open air space, pit, Shane, structure, Tips |
No Comments »
The Truth About Cryogenic Processing for Improved Characteristics in Metals
In order to fully appreciate and understand the process of cryogenics, one must have a basic understanding of the purpose of heat treating.
Parts to be hardened are heated by one of several different methods, none of which are important to the understanding of the cryogenics process. Tool steels are generally pre-heated to a fairly high temperature before they are then soaked (a certain temperature a metal is held in is referred to as a soak) in their final heat treat temperature. This allows for temperature equalization of the metals throughout as well as sets the grain structure to allow for better transformation in its austenizing temperature.
Lower alloy steels however, are not preheated but are soaked directly at their austenizing temperature. Austenite is the name of the grain structure that forms in ferrous steels at this critical temperature. It is this austenizing temperature, along with the correct amount of time that allows for the metal to transform to this austintenic grain structure. Austenite grain structure is a very large, coarse, irregular, loosely bonded structure. At this critical temperature the metal has essentially melted within its own physical structure. The molecules are now free floating with no bonds to one another.
There are many variables in this stage that can determine the amount of retained austenite in the next stage. However, it might also be noted that cryogenics can fix some of these problems, although it should never be used as a “band-aid” to repair sloppy heat treatment.
After the austenization soak the metals are then quenched. A quench is a removal of heat at a controlled rate; this rate is dependant on the alloys the metals posses. This is a deliberate action to motivate transformation of the austenitic structure to the preferred martensitic grain structure. This is the grain structure that is highly resistant to wear. The martensitic structure is a much more refined, hardened, smaller, tighter, and stronger bonding grain structure. To accomplish the transformation the heat must be removed from the metal. This is one of the most critical steps in heat treating, if the temperatures and times are off, then transformation will not be of ideal structuring.
The parts will be quenched to a temperature of approximately 65°C. At this stage the newly formed “raw” martensite is very unstable and needs to be tempered in a tempering oven to stabilize the structure. There is also a slight transformation of some retained austenite to martensite in the temper. Tempering steel after fresh martensite is formed is an absolute must as the highly unstable behavior of the grain structure can crack or shatter.
This ends the heat treatment process; however there still remains untransformed retained austenite in the metal. Even though a very high quality controlled heat treating may give up to 90% transformation, it is very highly unlikely in batch applications. The usual transformation for a good heat treatment is around the 60-80% mark, with poor treatments falling well below these percentages. However even with as little as 2-3% retained austenite, the difference after transforming the remainder can be very significant.
Cryogenic technology to continue the transformation to 99.8 – 100%, increasing wear resistance in heat treated steels.
Cryotron cryogenic equipment, designed to do a deep cryogenics process – often incorrectly referred to as “cryogenic tempering” – uses cryogenic temperatures (-196°C, -320°F) to transform the retained austenitic grain structure, into the smaller, stronger, more desirable martensitic grain structure. Hereby enhancing the molecular bond within the properties of the metals and giving them greater strength in several areas, including drastic increases in wear resistance. The transformation rate is much greater than that of heat treatment alone and will get a rate of about 99.8 to 100% transformation. However, Cryogenics should not ever be considered to replace the heat treatment, it is a complimentary treatment that enhances what took place during the heat process.
To add to the mixture; during the cryogenic process there is also a precipitation of fine eta carbides throughout the metal; this is in addition to the larger carbides already present in the ferrous metals. These fine carbides increase the bond mechanisms within the molecular structure of the metals, which in turn increases wear resistance again.
Once again, the metals are taken out of the cryogenic equipment and tempered in a proper tempering oven to stabilize the newly formed martensite.
When the process is complete, the metal is a tougher, stronger and a much more durable substance than before. Cryogenic processing is a thorough process and permanently alters the entire thickness of the wear resistant metal; it is not just a coating or surface treatment. This deep cryogenic treatment also relieves the stress built up by the heat treatment process, as well as any residual stresses that may subside from the manufacturing and/or machining process. Please click here to read more about cryogenic stress relief, and the array of materials the treatment will work on including castings.
The combination of the newly formed martensite and stabile stress relieved material makes the surface of the metal less porous, so there is more surface area to wear; again adding to the arsenal against wear.
However, the process will not work on all metals to improve wear characteristics as believed by some. If the carbon content is too low, or the proper heat treatment is not done correctly, the results may not show any value at all, or may even show the contrary. An assessment may be critical on some metals to find out more information in the chemistry and heat treatment practices done to properly determine the outcome of a cryogenic treatment.
As for the speculation over whether or not cryogenics can act as a stress relief, yes it can. As documented in the ASM “Handbook of Residual Stress and Deformation of Steel” it was proven at both the Technologic Institute of Louisiana, and the Technical University of Jassy, Romania that cryogenics will work to favorably redistribute the residual stresses throughout the entire part.
Cryogenic treatment has been documented throughout the scientific world as a means to improve wear resistance in many heat treated metals and thoroughly relieve any built up and residual stresses. It is not a cure all “snake oil” as is read in many places on the web, but it will significantly improve several characteristics in many metals in areas that are beneficial to some. There is no need to do a cryogenic treatment on your silverware at home, as it will not be beneficial. However, if you are having breakage problems with a high torque part, or abrasive wear problem at work, a cryogenic treatment is something to look at.
Metal Casting
Posted in Uncategorized |
Tags: alloy steels, C. At, grain structure, heat, structure, temperature, tool steels |
No Comments »
