Posted by Rick Denney on October 30, 2002 at 15:33:55:
In Reply to: Fitting a new leadpipe + fifth valve posted by Dave Erickson on October 30, 2002 at 15:06:35:
I would recommend getting a valve designed to be a fifth valve, if possible. The through ports on the player's left side point up and down, but the valve branch ports usually point to the side. A fifth valve has the top branch port pointed up, and the lower port to the side, so that the tubing will go straight up from the valve and then curve into it at the lower port. If you use a first valve with side ports, you may have to turn it at an angle so that the tubing will extend in front of other tubing. This wouldn't be bad, but it will complicate the linkage and give the horn a "unique" look.
As to bending a leadpipe, repair techs don't use tar, they use pitch. Similar but not the same. Pitch is very stiff to the point of being brittle, and it is finicky to use and requires practice. Most hobbyists use lead. Take the straight pipe, stick one end in a bucket of sand, and poor molten lead through a metal funnel in the other end. Play a torch over it to melt the lead in the pipe to make sure any voids have bubbled out. When the lead hardens, you can bend it around your form, though you will still have to round out the bends with draw rings unless you are lucky. Then melt the lead, working from one end (!), so that it has all flowed out. Most pros use pitch, but they have lots more practice, too.
If this tuba uses the same tubing diameter as a Miraphone, you can get the pieces of tubing you need to construct a fifth valve easily, so that you don't have to bend any of the tubing. I have the parts, but my valve is a first valve and I haven't taken the project on yet. I need more practice, and probably someone willing to trade a fifth valve for a brand-new first valve.
Rick "with too many projects as it is" Denney