8.1 Pro's and contras of the ''do it yourself'' approach

The fact that a ferrocement gasifier can be built at any location, using locally available materials and a few simple tools, fits perfectly into a self-help strategy for underprivileged parts of the population. In fact, encouraging proper engagement of the target group of rural development programmes helps to avoid a wide spread "gift mentality" and seems a promising approach. Some pro's and contras with respect to owner-built ferrocement gasifiers will be discussed here.

The way how to manufacture a ferrocement gasifier has so far been documented in the manual of R. Reines [9] and Alan Gonzales/ Bui Tuyen [10]. These documents are adequate to inform the scientific and technical staff of an institution, that means, to inform the later"multiplicators" of a know-how transfer. But a written manual is not helpful to people with a low educational level. The capability of people in rural areas of developing countries to read and to interprete written instructions and blueprints is very limited.

Making vessels by handling wire and cement seems to be an easy job which can be done by anyone with average skill. Basically this is true, but it should not be forgotten that the typical, interested potential user is an absolute beginner. He has, normally, to learn how to work with wire and cement mortar, but simultaneously he has to get an idea what happens in a gasifier of the type he is just building. This is more complex than it may appear. At the educational level which can be expected in developing countries, a do-ityourself approach can only be realized with the help of well-trained instructors. Patience and care are the most important "skills" which have to be trained with any new group.

It is not only the necessary skill which has to be considered in a do-it-yourself concept. Financial aspects play an equally important role. At first glance, do-it-yourself seems to be by far the cheapest solution to acquire a gasifier. But, it has already been said that the do-it-yourself method depends on well-trained instructors. In rural development projects the salary and the travel expenses of the instructor will normally be covered by governmental institutions or donor agencies. If not, the costs of the instructor are a relevant part of the overall costs.

As soon as a relevant number of gasifiers is to be installed within a certain area (forming a "cluster" of gasifier application sites), a commercialization of the gasifier manufacturing is a recommendable way. The following principle has been tested in Bremen as well as in Argentina [ 1 1]: At the manufacturer's place, all the inner cylinders and attachments are completely prefabricated (see figs. p. 16). These components are transported to the site of installation. At the site, the large cooling tank is built and the final assembly is done with the participation of the later user group. In that way, the construction is done effectively by trained personnel, and the final costs are still low due to the low level of labour costs.

A summary of these considerations is:

- The do-it-yourself method is not always applicable. It is possible that the user of the plant is not interested in investing his own time and prefers to pay for it. This is realistic, considering the low labour costs in developing countries, which make the ferrocement concept so cheap.

- It is possible that manufacturing by the users (a community) is difficult to realize for reasons of insufficient availability of qualified labour.

- For the above reasons, the promotion of local manufacturers of ferrocement gasifiers has to be considered as an alternative or as a supplement to the self-help approach

- On the other hand The self help approach may not be always applicable, but at least this possibility exists. This is not the case with conventional gasifiers, which always require the facilities of a rather well equipped metal workshop. If the participation a of team of community members-preferably the later operator team-can be organized, and if the operation and maintenance of the gasifier is reasonably integrated in the economic activities of a community, the self-help approach is a unique chance to save investment costs, acquire the necessary qualification, and settle responsibility for the equipment.