Electroplating and Annodizing

Electroplating, the process of coating a metal object with a thin layer of another metal.

Method:

1) A container is filled with a solution of a salt of the metal that is to form the coating.
2) The object to be coated with the metal is connected to the negative terminal of an electric battery and therefore this then becomes the cathode (the negative electrode).
3) Then when the electrical connection is established the metal that is connected as the annode starts to leave and form onto the outer layer of the cathode.
4)The longer you leave the process happenning the thicker the layer of metal that forms on the cathode.

Electroplating is used to give metal objects a better appearance or to protect them from corrosion, wear, or rust. Tableware, trays, decorative pieces, and jewelry are plated with gold or silver to make them more attractive.

















Annodizing is a very similar process however process to electroplating however there can be the introduction of a dye and this is how many of the parts gain its colour. Also there is more players built up during the annodizing process so that the layers of colour can build up so they are harder to remove. Then a lacquer is applied to seal the result and maintain the colour from weathering.

Metals and Alloys Notes

Iron - is converted from ore to solid metal by heating. After the impurities are removed from the furnace when it is cooled a greyish metal.  Iron is rarely used when its not combined with Carbon as otherwise its not strong enough to fulfill the needed purpose. The result of mixing Carbon and Iron is Steel.

Steel - Is a mixture of Iron and Carbon. The percentage of carbon in the steel determines the strength. Alloying this material with other materials enhances the properties of the steel giving it different specific properties. These properties can include the resistance to corrosion.

Carbon - Carbon is an element found in a range of materials. Organic materials including Diamond and Coal are made of pure Carbon they are just produced under a different degree of pressure. The amount of Carbon in Steel can change the properties.

Iron and Carbon - Iron is generally soft and ductile which does not make it very commercially useful. When Carbon is added which is a very hard, brittle element. When it is mixed with Iron it can be used for the following qualities;

• The hardness is increased
• The toughness reduces making it more brittle.
• Can be heat treated to increase strength and hardness.

PD AS Coursework December

Tanalising Timber Process

Tanalising Timber Process

1) The Tanalising process involves placing the timber within the treatment cylinder and creating an initial vacuum within the cells of the timber.

2) The cylinder is then flooded under vacuum with the preservative treatment.

3) Hydraulic pressure is then applied forcing the preservative deep into the timber cells.

4) After a pre-determined period of pressure depending on the species of timber being treated and its eventual use, the treatment solution is pumped back into storage and a final vacuum extracts any excess treatment solution from the timber.

5) Low pressure inside the timber draws in surface solution when vented to the atmosphere and the treated timber is left for a specified period for fixation of preservative to occur

Wood Joints

Wood Joints


This is a Mortise and Tenon joint and it is a traditional joint and is popular due to its strength. A mortise is simply a hole in the piece wood and the tenon piece slots inside. There are many different forms of mortice and tenons and also uses – but they are mostly used in tables and doors. The reasons why people use mortise and tenon is because it is very simple concept however is extremely effective and quick to manufacture.




This style of butt joint is the simplest of all methods of joining two pieces wood together. However the strength of the joint relies entirely on the glue and any additional fixings such as screws. This type of joint is often used on bed frames as it causes the different parts to be lined up so the product fits together correctly.

Steam Bending Notes

Steam bending is a technique used on woods in order for them to change shape. During the process strips of wood/timber are steam heated using a steam box.  A steam box is a long sealed container which is where all of the steam bending process takes place. Then the heat and mositure makes the wood more flexible which allows the timbers shape to be changed. However during the process the shape has to be held by a mould so that is doesn't have chance to change back to its original shape.


Steam bending is relatively cheap, effective and quick however there is a disadvantage that the wood can only bend to a certain degree. Which can be a pain depending on the purpose that you want to use the wood for.

This is a image showing a steam box

 

This is showing a steam bending jig

Manufactured Boards Notes

Hardboard: is a high-density wood fibreboard and a standard material used in furniture making and in the carpentry industry. The production process results in one very smooth side and a rougher side due to the way that it is manufactured. It is a extremely dense fibreboard. It is manufactured and sold at a thickness of 3mm.

Plywood: is a manufactured board that has properties including increased stability, high impact resistance, dimensional stability, high strength to weight ratio,  chemical resistance. Plywood is generally known as an assemblage of wood veneers bonded together to produce a flat sheet. Which is machined to a thickness of 6mm and is sold at that thickness.

Blockboard:is made up of a core of softwood strips that are extremely thin. These strips may be up to about 25mm wide however they are normally . The strips are placed edge to edge and sandwiched between veneers of hardwood. The sandwich is then glued under high pressure. In order to compress it and make sure that no water enters any gaps that are left. It is sold at a thickness of 18mm and this is the thickness that it is machined to this thickness initally aswell.

Chipboard:is made by gluing together wood particles with an adhesive, under heat and pressure makes chipboard. This creates a rigid board with a relatively smooth surface. Chipboard is available in a number of densities: -normal, medium and high-density. Is sold at a thickness of 18mm.

Medium-Density Fibreboard (MDF)- is a reconstituted wood panel product. It is a dry-processed fibreboard manufactured from wood fibres, as opposed to veneers or particles, and is denser than plywood and particleboard. MDF has an even density throughout and is smooth on both sides.