Date: Fri, 27 Aug 1999 12:23:06 -0400 (EDT)
Subject: Re: How to build a natural trumpet

> A while back there was talk of instructions for building a natural
> trumpet using a spare trumpet bell.  I have a bell that I'd like to use
> but I don't remember how to get a hold of the instructions.  Can anyone
> help?  Also, I just got ICQ if any of you want to talk trumpet.

This can be a very rewarding project, however be aware that a modern trumpet bell will probably not be as easy to play in tune (without vent holes) as the shallow flares of the early baroque instruments. Making a trumpet is not very hard to do crudely, although it depends a bit on what you have to work with.  If you can find a pair 180 degree tubing bows (know anyone who has cut the valve section out a a french horn to make a natural horn?) those will simplify things a lot.  But you can make them yourself, it is just harder and involves pouring molten metal.

You can get the basic tubing from a company called "Small Parts, inc" in Florida.  They have a web site, but not an online catalog.  You want three 36 inch pieces of 15/32" tubing with .014" wall.  That gives you a bore of around .440 which is about right for a natural trumpet.  You also need a 12 inch piece of the next larger size to make ferrules.  Get a short piece of the next smaller size if you want to use a modern trumpet mouthpiece (not recommended).  You might even want to get a piece of 16/32" tubing (which will have a 1/2" inside) or even larger to connect to the end of your bell where you will cut it just above the bow.

To bend the tubing for the bows at each end of the trumpet, you have to first soften it by heating with a propane torch until it just begins to glow, then let it cool.  Coat the inside with motor oil by swabbing a bit of paper towel through it.  Make a wooden plug for one end from a dowell and plant it firmly in a large bucket of sand.  You will also need a metal funnel that can fit securely in the open end. WORKING OUTSIDE, wearing long pants and sleeves, shoes, leather gloves, and a face shield, melt about a roll and a half (1.5 lbs) of Oatey lead-free silver plumbing solder (about $20) in a small saucepan (that will never be used for food again).  Hold the top of the tube in a pair of slip-joint pliers and carefully pour the molten solder into it.  You can hear it filling up by the rising pitch of the droplets. Tap the tube with a piece of wood to bring any air bubbles to the top, then leave it to cool.  (And David, this is really something you must discuss with the parents before attempting).

Once the tube is cool, you can bend it by hand around a form, either made from wood, or buy a cheap brake line bender at the auto parts store.  Wire each bow with the ends down to a firebrick and carefully heat (working in from the ends with the torch) to melt out the solder. Be especially carefully not to heat in the middle of a full section of tubing, as enough pressure can build up to make it explode, throwing molten metal all over you.

With that accomplished, actually building the trumpet will be simply a matter of cutting the right tubing lengths and joining them together, eitehr in the modern style with flush ferrules and perhaps solder, or the traditional method of shrinking one tube and expanding the other until they fit together, with the ferrule over the outer tube as reinforcement and decoration.

See the "do it yourself" section of my web page.  And please be carefull when working with hot brass or molten solder!


PS - you might also want to look at under wind instruments, and track down a copy of the book "The Art of the Trumpet Maker" by Robert Barclay.