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Showing results for tags 'The arguments for and against'.
David Coram's mention of fibre-board being used as a material in the Compton organ at St Geroge's RC Cathedral, Southwark, sent me on a bit of a "google" concerning the materials now often used in organ-building. In the process, I discovered things that I didn't know, including a few "thumbs down." In fact, when I started to search, I wouldn't have known that there was a difference between hardboard and what we call MDF, but in fact, there is a huge difference in the make-up of the materials. At the ouset, let's draw a veil over "chip-board," which is a fairly brittle and rather horrible material probe to the effects of even modest damp. On the other hand, we must include the best marine quality ply, which has been used very successfully by many organ-builders. It would seem that hardboard is a completely natural material: in effect disintegrating real wood, autoclaving it, deliberately venting the autocalve pressure suddenly and allowing the fibres of the wood to literally explode. The bonding resin of the original wood is effectively re-used, producing a grainless, very consistent material, which can then be accurately worked and machined. The effects of damp can be protected against by the use of various varnishes: not that hardboard is especially bulnerable to mildly damp conditions. MDF (medium dense fibre), is a very different material, though broadly speaking, it is similar to hardboard, except that it uses formaldehyde as a chemical agent in the bonding resin. A couple of thumbs down seem to be given on the basis that it can easily be gouged and chipped, and screws do not hold well when undone and then re-tightened, which explains why MDF furniture manufactirers tend to use special fixings. One of the more alarming things I have discovered about MDF when used for toe-boards, is a tendency for metal pipe-feet to corrode very rapidly, which may have a lot to do with the formadehyde in the bonding resin. (The jury is out on this at the moment). What I find interesting, is the fact that there are a vast number of materials from which to choose, and a similar range of quality, just as there is with real, seasoned timber. The intial question is simple. Why should natural wood be any better for organ-building than the best composite board, and if it isn't, is it just a matter of tradition and pride that it is used? To put it another way, if you were a consultant engineer called into investigate organ windchests, which path would you choose; contemporary materials or traditional ones? MM