Thursday December 5, 2013

Day 29..

Flashdance eat your heart out.. Today we we're let loose with an Electric Arc welder.. This method of welding uses an electric arc to melt the metal whereby the current flowing into the circuit can be manually changed (between a range of 25 to 250 amps) to create more / or less heat in the arc. We got kitted up; leather apron and gauntlets (gloves) goggles and a welding mask then watched a demo of how to get the arc lit and create the molten pool thus creating the weld! It was then time to have a go ourselves, we took 5/6 electrodes (arc sticks or rods) - covered in a flux coating to protect the surface from the atmosphere, and entered individual welding booths. Here we took a metal tile and simply had a practice at striking the arc and welding! i took a few goes to get going as it was quite difficult to strike! and the rod kept sticking to the metal plate! however i did get the hang, and tried to make some straight lines!. It was a little scary, and the knack is to go quite slowly moving the rod downwards to get the molten pool flowing and gently from side to side to create a nice ripple effect! both of these techniques were quite difficult for me as a first timer! But i then moved on to joining two small pieces of the same metal together to see how well and deep the molten pool penetrated the metals to fuse them together. The flux leaves a top layer called a 'slag' so this is removed by chipping it away to reveal the weld. Once cooled in a bath of water, i used a hacksaw to saw the welded metal in two to discover how deep the molten pool of metal was - i.e. was the join showing of the two joining pieces? - i had made a slight pool with a little weld on top but did not quite go as deep as half way! i will try harder next time! and we also got to keep our pieces as souvenirs!

Our theory topic this afternoon was worming and parasites.. there are three major diseases in sheep that are caused by worms; Tape worms and liver fluke; roundworms and lungworms so it is necessary to treat the animal with wormer to prevent an attack which can be fatal. Parasitism - is the association of two organisms, one of which is the parasite that nourishes itself at the expense of the other called the host, but usually without destroying it! It is important to note that the adult parasite produces the egg while inside the body of the animal but the eggs do not reach maturity unless they have been passed out of the body first and sustained a period of life outside, so because they live on the grass (after coming out via feces) the animal ingests the parasite while grazing and thats how they build up and attack the animals insides. Good husbandry and grassland management is key to reducing a worm attack, worming animals as they enter new grazing pasture and by mixed grazing where possible, allowing other animals on to graze the same grass - as worms are susceptible to their hosts and therefore do not remain active in another animal.

We then moved on to the calving season of a suckler herd and discussed different reasons that would have an effect on what you do and when such as the type and situation of the farm - much harder for a hill farmer than a lowland farmer for example; availability of labour - where it is busier during the harvest period for example; feed supply - with more being needed during the winter months; when to sell the calves - ensuring you aim for the right market and availability of buildings - whereby infrastructure needs to be in place for calving and rearing to produce a good quality end product! As two groups we discussed these points and listed the advantages and disadvantages accordingly.