Aluminum alloys are used in engineering design chiefly for their light weight, high strength to weight ratio, corrosion resistance, and relatively low cost. Aluminum is the most widely distributed of the elements, except for oxygen, nitrogen, and silicon. Aluminum alloys weigh about 0.1 pound per cubic inch. This is about one third the weight of iron at 0.28 pounds and copper at 0.32, is slightly heavier than magnesium at 0.066, and somewhat lighter than titanium at 0.163
Which Welder to buy?
For the majority of people (those who don't have any special requirements) a DC inverter is the best type of arc welder to look for. They are the easiest type of arc welder to use, portable, and less demanding on power supplies than other types of arc welder.
Even the cheapest Chinese inverter welders perform reasonably well, but at the time of writing (2010) they aren't known for their reliability or support. There are many reports on the forum of cheap inverter welders failing within a few weeks of purchase. eBay tends to be the source and warranties can be tricky on there. Chinese made welders are best purchased from established UK based suppliers who can satisfy the warranty. It is in the interest of these suppliers to supply half decent ones to save on warranty claims.
Inverter welders do go wrong - they can be sensitive to knocks, power surges from the mains, dust and internal corrosion. Repairs will often cost more than the welder cost to buy in the first place. The difference between Chinese and European made inverters tends to be how sensitive they are to damage. And as a result how long they last.
